The JBL 4345 Club

[Ian Mackenzie]

Some members have mooted why we do not have JBL 4345 Club.

Well we are not aware of that many owners on the Forums.

However there are some potential benefits of forming a club such as sharing technical help, upgrades and the opportunity to communicate with other JBL 4345 owners.

So for those members who are currently owners you may wish to register you interest.

There appears to be a raft of posters who are more intent on watering down the prestige of owning these magnificant monitors of late.

We are not interesting in those members identifying themselves here.

For this reason you may wish remain private and send me a pm rather than post here.

This club will remain exclusive to 4345 owners or those currently in the process of building the 4345 to JBL specifications.

[Ian Mackenzie]

JBL 4345

[Ducatista47]

Ian, I might suggest that former owners, if Subwoof is any example, may have a lot to offer in the way of ideas and assistance. I imagine Ken may have some valuable opinions as well. Didn't he own a pair before his Westlakes crowded them out of the house?

Clark in Peoria

[Ian Mackenzie]

I welcome all feeback. That which was deleted was obviously "stupid" noise.

Yeah well given recent events someone like Ken might qualify for an honorary life membership.

Good ideas to all who are interested.

I was only testing the waters. I just think there is merit in there being a "focus" in specialities like this.

Its unfortunately that we have so many members but such few active posters and the ratio is growing at an exponential rate.

No doubt there are more owners or former owners we would like to hear from

[Ian Mackenzie]

Travis,

I had to think of a way to filter out the usual spam we usually get in these types of situations. The intent was not to make you react they way you did. I Read your post and it does not bother me in the least.

I also wanted to make a distinction of are you in or are you out in your own words. You are by your own admission out and that is fine.

There is nothing wrong with a diy variation as long as the distinction is made with the original design in the technical sense specifically.

This is one of the key reasons DIY was split from the technical forums and whole gist of this is about preservation of Lansing Heritage of JBL designs per say.

About the 4345 its actually taken a hell of a lot of effort over the past 3 or 4 years by only a handful of members to gather up all the information and do the technical research into this perhaps little known model and to bring it forward to where it is today in terms of awareness on the forums.

If you think you can pick all of that in 3 months you are obvisously an exceptionally gift designer.

Otherwise its very easy to pass off something as just another model in the line. Sadly this is what tends to happen and people in their passion and haste can pass over what it was and is without an inckling of it was really about.

[saeman]

Some members have mooted why we do not have JBL 4345 Club.

However there are some potential benefits of forming a club such as sharing technical help, upgrades and the opportunity to communicate with other JBL 4345 owners.

So for those members who are currently owners you may wish to register you interest.

There appears to be a raft of posters who are more intent on watering down the prestige of owning these magnificant monitors of late.

We are not interesting in those members identifying themselves here.

For this reason you may wish remain private and send me a pm rather than post here.

This club will remain exclusive to 4345 owners or those currently in the process of building the 4345 to JBL specifications.

Hello Ian: I'm affraid I'm lost in trying to understand the issues here.

How will this New "Exclusive 4345 Club" work? Will the members have a special password they can use to access a special 4345 section of this "Public" forum - set up exclusively for 4345 Club Members only. Will there be a court with a king, queen and wards? It's been some time since I've had a pair of 4345's but if there will be a secret handshake for clubmembers, I'll definately be looking for a pair so I can join.

For all owner's of 4345's who want to discuss the many attributes and the design of this fine monitor I would suggest using the "DIY" or "Technical" areas provided within the LHS Forum Structure. What's wrong with sharing 4345 info with all forum members - like all other JBL info is shared with "all" forum members? For "Top Secret" matters they can simply converse and share information via "PM".

[Ian Mackenzie]

Travis,

It was special moment when I met Bo and heard his 4345's.

Yes I was convinced and I still am.

It was worth the long journey across the Pacific and a hair raising 30 mile car chase on roads in a foreign land I had never before seen.

Such is the wild west.

[Ian Mackenzie]

Hello Ian: I'm affraid I'm lost in trying to understand the issues here.

How will this New "Exclusive 4345 Club" work? Will the members have a special password they can use to access a special 4345 section of this "Public" forum - set up exclusively for 4345 Club Members only. Will there be a court with a king, queen and wards? It's been some time since I've had a pair of 4345's but if there will be a secret handshake for clubmembers, I'll definately be looking for a pair so I can join.

For all owner's of 4345's who want to discuss the many attributes and the design of this fine monitor I would suggest using the "DIY" or "Technical" areas provided within the LHS Forum Structure. What's wrong with sharing 4345 info with all forum members - like all other JBL info is shared with "all" forum members? For "Top Secret" matters they can simply converse and share information via "PM".

Hi,

Rick..nice to hear from you.

Well I don't think there needs to be a corporate structure a such.

Its more Sunday school gathering of like minded people who believe in what they have or had or aspire to and to share experiences.

Yes I think it would be appropriate figure out where to have it. Ideally all the technical stuff should go in the Techncial forums and obviously this would become a useful reference for restorations etc. The actual projects might better be in the Diy forums.

A specific thread like this is cool for a chat..as I said the inital reference was a filter and a focus.

If it as felt there was a need for special place and there was justification it might be considered.

What might be useful is photo gallery "collection" and a private pm or email steam for anything else.

[alskinner]

Building a clone of the 4344 has been one of the most challenging and rewarding endeavers I've undertaken. The one thing that helped more than anything was Ian's and Bo's Building the 4344/4345 threads and Giskards work on the crossover. Also, Not only was the thread an excellent step by step instruction on building the boxes but the amount of time taken by the individuals to remain true to the original design was much appreciated by me. But, the one thing that made the thread so good was that it stayed for the most part on target without the usual off topic rhetoric that destroys so many good threads. After two years into the project I have got the 2245hs to build the 4345. One thing I did find is the 2122h is essential, I tried every other 10" imaginable and nothing gells the system like the 2122h. I have a deep respect for the original designer and the amount of research and effort it took to make this outstanding speaker. Can it be made better, possibly, but for me to have the orignial design down pat, will be the only way I'll know. I for one would like to see a section devoted to the purity of the 4345.

[Ian Mackenzie]

Hi Al,

Purity, the sums it up beautifully.

Nice post.

Ian

[Ducatista47]

In that case, I can be the village idiot. Hope I can still carry a sword or a staff.

Tell you what, Giskard. Convince Bo to sell his and I'll give it some thought.:)

Clark

[Ducatista47]

Not at all, sorry to offend. The drivers are better, and soon to be better yet. Greg is a genius and knows more every passing year, I'm sure. I have not heard any K2 or a 250TI, so I speak from some ignorance. But the overall synergy of the 4345 still seems to invoke superlatives from experienced listeners. I think there may be something to it.

Reading your added material in your response, I see I owe you an apology for real. I am still pretty new here, and not an audio professional. I had little idea what you were up to, and I hope - and imagine - you will succeed, if indeed you have not already, in what I most want to see accomplished. How about I say I am really sorry, and you have even more of my respect than you had before, which was considerable. I meant to talk up my favorite speaker and its designer, and I seem to have insulted you and Greg instead. Can I still be the village idiot?

Peace, Clark

[Ian Mackenzie]

Giskard,

Speaking of upgrades, Are you going to talk about Diaphragms? Huhmmm

In recent times I would state my sword on the diaphragm as the most noteable improvement.

I doubt whether it would be worth the trouble in the lesser 43XX designs but in the case of the 4345 it deserves a mention.

[Ian Mackenzie]

]

No doubt but that is privilaged information and they are not Heritage products per say....you have been spoilt .:D

[Ian Mackenzie]

They are a more worthy compliment but on lesser systems possibly not.

The 4344Mk11 used acquaplas as I recall. You know GT's thoughts on the matter and one would imagine he would use them a second time around.

I think we should pontificate on this further for the benefit of the rest of the Order.

Edit. The distinction seem to be more obvious on classical music were natural tones are more easily identified with greater timbre accuracy and with masses strings and percussion where the stop start of transient is much clearer.

Ian

[Ian Mackenzie]

I have edited post #8 because apparently (although I have not seen evidence as yet) some from within the masses were a bit put out by the change of thinking that sparked this thread.

This thread is just a focal point for those who are deeply passionate about a particular subject and that is the purpose of this thread. To share and to enjoy experiences about this loudspeaker and to discuss how best to attain maximim listening pleasure.

If you think you are as deeply passionate as the owners and users of the 4345 you are welcome to post here.

Similarly, if you are very passionate about what you have ie a 250ti, a 4333 or an L100 you might want to get together for a good chin wag

Please do not be offended, this is not a private meeting room.

If you do have concerns send me a pm.

At this point I have only had positive feedback

[saeman]

Yo Down Under: Your post #8 was fine the way it was. I can't see how it could have offended anyone. A little Aussie humor now and then helps take the edge off. See Ya - Rick

[Ian Mackenzie]

Yes exactly,

However trans continental cultures and mindsets often get these scewed up.

I saw a great movie last night The Worlds Fastest Indian. Aside from the immense Utah Salt flats the story was facinating and will ring true for many.

http://www.imdb.com/title/tt0412080/

[Ian Mackenzie]

While I don't want to be seen as leading anything here perhaps we need to list a few initiatives and take on board what members globally might be interested in seeing arranged.

This might take quite a while to action but a list of what would add value is useful. We can work out the how , who and when over a forum beer.
I am sure there are other items so please elaborate.

Product Profile

There is not as yet a product profile in the Library of the 4345
An account of this model and how it came about would be quite interesting.

Owners manual

I don't think there is one but l am sure we could work on something and perhaps use something along the lines of the 4344Mk11 OM as a template/guide for the contents.

This could be quite a job to work on and would make a great project.

Photo Gallery.

I have some images on my HD. I'll bet others have some as well aside from your own set up. We need to do something with this.

Members Systems.

This could be part of the photo gallery but that would not allow discussion and questions. Members stuff like Bo's has been talked about from time to time but what is out there is fragmented.

Maintenance and upgrades

Part of the manual. A while ago I did some stuff on the 4344. Some of it applies but there needs to be a revised focus on vintage 4345's.

Building a 4345

Cad drawings. I know we have some basic drawings but there is a need for some proper drawings. I recall Rick and someone else has done something. We need to update where we are at here.

Serial number registry

[hapy._.face]

over a forum beer

only 1 ?!

[Ian Mackenzie]

only 1 ?!

When I first joined my local audio club..The Melboune Audio Club I was asked if I would like to attend Sunday School with the Lad's.

Wanting to fit in so I turned up and was the odd man out without an Esky( a beer cooler that holds a slab of Fosters).

[hapy._.face]

When I first joined my local audio club..The Melboune Audio Club I was asked if I would like to attend Sunday School with the Lad's.

Wanting to fit in so I turned up and was the odd man out without an Esky( a beer cooler that holds a slab of Fosters).

What's 'odd' about that? How else were you supposed to keep your beer cool? :D

[Chas]

While I don't want to be seen as leading anything here perhaps we need to list a few initiatives and take on board what members globally might be interested in seeing arranged.

This might take quite a while to action but a list of what would add value is useful. We can work out the how , who and when over a forum beer.
I am sure there are other items so please elaborate.

Product Profile

There is not as yet a product profile in the Library of the 4345
An account of this model and how it came about would be quite interesting.

Owners manual

I don't think there is one but l am sure we could work on something and perhaps use something along the lines of the 4344Mk11 OM as a template/guide for the contents.

This could be quite a job to work on and would make a great project.

Photo Gallery.

I have some images on my HD. I'll bet others have some as well aside from your own set up. We need to do something with this.

Members Systems.

This could be part of the photo gallery but that would not allow discussion and questions. Members stuff like Bo's has been talked about from time to time but what is out there is fragmented.

Maintenance and upgrades

Part of the manual. A while ago I did some stuff on the 4344. Some of it applies but there needs to be a revised focus on vintage 4345's.

Building a 4345

Cad drawings. I know we have some basic drawings but there is a need for some proper drawings. I recall Rick and someone else has done something. We need to update where we are at here.

How about a serial number registry specific to 4345's, too? It might prove interesting.

[Ian Mackenzie]

Good idea!

[Ducatista47]

My babies are #12511 and #12555 They are a matched pair, left and right.

4345 #12555
2421B......#11604
2405...no name plate!
2308 Lens...#79778

4345 #12511
2421B......#12770
2405........#121990
2308 Lens...#79791

2245H's and 2122H's are not original.

It will be interesting after a public post like this to see if they show up on eBay in Singapore or Nigeria.:D

Clark in Peoria

[Ian Mackenzie]

Good stuff.

[gtimbers]

I can't belive all the interest in this 30 year old system. It was never very successful during its life time primarily due to its size. Most people would get something smaller. It also had a reputation for less than detailed bass, which I have always thought was due to the enclosure not being quite large enough. I haven't thought about these things in years but since I have received a few requests for comments - here goes.

The system was and probably still is a stellar performer if you like the inherent sound of the traditional big JBL 4-ways. There is good news and bad news in the basic design. Good in that they are dynamic as hell and never get confused with intermodulation products of any type. They don't take much power to run and can swallow up a really big amp should you wish to do so. The weak areas of that type of design are several. First, there is a large time off-set between the 10" driver and the HL92 horn. This shows up in both the on-axis response, the directivity pattern and the homogeneity of the driver blending. The second problem is the use of a passive crossover between the top of the woofer and the bottom of the 10". Passive crossovers set to frequencies below about 500 Hz react badly with the motional impedance of the woofer/box combination and give substantial gain around 100 Hz. Gain out of a passive system is generally a bad thing. In the case of the High Pass, we have to work the passive network through a really large motional impedance peak resulting from the 10" fundamental resonance in the sub enclosure. This means that the actual voltage drive that occurs at the terminals of the 10" is less than ideal. There was the added complexity that the Marketing folks of that time required switchable bi-amp capabilities in which the incorrect setting of the switch was not allowed to hurt anything. These little things all add up to additional insertion loss for the woofer and loss of damping control. Now all of this sounds pertty bleak, but as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway.

My sonic memory of the big 4 ways, the last of which was the 4344MkII, is that they are effortless, dynamic, pretty low in coloration and really "alive". They are a little vague by today's standards in terms of precise imaging and although they are very low in intermodulation effects, they are not as detailed as really good lesser way designs. There is no simple answer to any of this and no one design statement that is best. Everything is a series of compromises, and the 4345 has a very good set of complimentary compromises.

I noticed a comment earlier in this string regarding the 2122H. It is a really good voice transducer. It always has been and always will be. Things just sound really natural through it. Another one that might be slightly better is the 2123. It is a little less smooth but perhaps a little more realistic on voice. Either are really good for that critical range from a few hundred Hz to about 1500 Hz.

I imagine you guys have talked about and tried lots of things to get the most out of the system. I will mention a few things that I would do if I had a pair at home for my primary system.


Get rid of the bi-amp switch. Hardwire it in which ever mode you want it. The switch is not that great.
If you can work out bi-amping do so. The difference in the 2245H and 2122H will be amazing. The crossover will have to be non standard. Neither driver is flat around crossover so the voltage drives will need to be adjusted to get proper acoustic bandpasses.
The network components should be updated and this isn't easy. All the capacitors should be polypropylene and you would want to use air core inductors where ever possible. I believe the 4345 used some tapped iron cores. Those are hard to replace with aircores because the surrounding network topology would have to change and all of the values have to be re-engineered. I would suggest leaving them alone unless you are really good at this stuff.
If you can swing it, go to a biased network. The difference is unbelievable.
The ring radiator hates passive networks. A major improvement in the upper range would be to drive the 2405 from its own little amp. You only need 3 or 4 v rms. The 2405 does 110 dB for 2.83v. It is padded way down in the system. There is little real power at those frequencies anyway. You only need to know the voltage output of the amp, power is irrelevant. The 2405 is about 12 ohms and won't draw much current. I would use some little chip amp with a 2ond or 3rd order low level highpass in front of it. Take off the passive network to the ring and just feed it straight. Make sure the amp doesn't make a DC thump on turn on or turn off. That will fatigue the diaphragm. The amp will also have to have really low noise characteristics as any hiss will be really loud directly into the ring. I used to use an old Marantz 1030 integrated amp to run my rings. I could separate out the power amp section and the tweeters always sounded really good.
The L-pads aren't so hot either, particularly after all of these years. Once you have your preferred balance, it is fairly easy to measure each leg of the L-pad and replace it with fixed resistors.
I notice from many of the pictures that the system is elevated on blocks. It is very good to get the 2245 up off of the floor to minimize midbass fatness.For resale reasons, you should be very careful about doing as much of this as possible reversibly.

Before closing I should comment briefly about the 250 - 4345 comparison. Simply put, I prefer a 250. I like the bass quality of the LE14 woofer. Alway have and always will. The 2245 when used as a dedicated sub is one of the best sounding woofers ever. It has an amazing blend of speed, pitch and punch. So does the 14" but the 18" is better. Unfortunately the 18" dislike for passive networks hurts it more than the 14" is hurt by a passive network. I think the mid and high range on the 250 is smoother and much more open however the 4345 wins by a bunch in terms of effortless dynamic sound. I have made all of the above changes to 250 systems (except for separate amp on UHF) and the improvement is huge. I have not done so on the 4345 but I suspect that that system will benefit from theses changes more than a 250 would. If both systems were tweaked out to about the same level, I suspect it would be very hard to come up with a clear overall winner, but I think I might lean towards the 4345 as having the greater potential.

Thank you all for the interest in my work. I must admit I have been blessed with a really nice profession that has treated me well for a very long time. Remember that sound and music enjoyment are very personal things and that what makes you happy may or may not please others. Screw them. If you are happy and no one is geting hurt then go for it. No loudspeaker system even approaches real life so there is plenty of room for interpretation.

[boputnam]

Thanks, Greg, for taking the time for such a generous and enlightening post.

[Ian Mackenzie]

Greg,

Thankyou for providing such a thorough and thoughtful post with your busy schedule.

Many thanks from Lansing Heritage Forums.

Ian

[Mr. Widget]

No loudspeaker system even approaches real life so there is plenty of room for interpretation.That is some mighty sage advice!

Ditto what Bo said!
Thanks,


Widget

[alskinner]

I for one appreciate your time and suggestions. Like you alluded to, in the end the most important thing is pleasing yourself.

Best Wishes
AL

[Robh3606]

Great Post!!!

Rob:)

[Chas]

Wow! I'm speechless...if only to say that to hear from the designer of a 22+ year old system (who actually recalls the minute details)...where else could this happen?

Thanks Greg, if I was to look back 22 years on my career, I couldn't be anywhere near as eloquent or as detailed.

I am now REALLY looking forward to resurrecting my recent Canadian 4345 acquisition and comparing them to my current set up.
Charles.

[JBLnsince1959]

Gtimbers:

it's a real pleasure to be able to learn the "real story". all I can say after reading your post is...WOW

Thanks for taking the time to post. It really means a lot to us.

[jomina]

My sonic memory of the big 4 ways, the last of which was the 4344MkII
Hi,

These

http://www5b.biglobe.ne.jp/%7Eannex/nankai/images/jbl4348.jpg
Don't count, then ;)

Joel - in Tokyo and off to demo a pair of 4428s later today. We'll be A/Bing with 4338s, which is a bit unfair, but that's life.

[JBLnsince1959]

Joel - in Tokyo and off to demo a pair of 4428s later today. We'll be A/Bing with 4338s, which is a bit unfair, but that's life.



Boy!! you guys get all the good stuff.:D

I'm going to have to go to Tokyo, see some friends and go JBL'n

[Ducatista47]

My sad, dead misbegotten thread seeking comparisons between the 4345 and the 250ti did not live and die in vain. As only one of the members voicing curiosity about some of the most beloved designs JBL has graced the faithful with, I add my heartfelt thanks to Mr. Timbers for presenting his take on the situation.

That take, of course, is the one I most wanted to hear. I am personally in debt for the rest of this millenium or so to Mr. Timbers for taking the time to craft his most informed, and above all thoughtful response to our curiosity. At no time did I ever think this magnificent response would ever really occur, being only the stuff of dreams for me. I would have been well and truely pleased by the most brief response possible. To be given an informed analysis as well as solutions for the shortcomings discussed, as well as personal feelings about the designs and our interest in them, I can't find the words. Well, there are five. Thank you very, very much.

I have to add that as an owner, I am a hog in heaven over all the detailed information about the 4345's. Who needs an old owner's manual when we can read this! I am glad I obtained my babies before this post. I can't imagine what the next pair, if ever offered, will sell for after this. As much and perhaps more potential than the 250, my goodness. Last week would have been a great time to bag a pair of 250's as well.:D

I think all fans of both of these speakers have been declared "winners," and I hope all are feeling as elated as I am right now.

I need to add that the newest owner has also read the post. He is pretty high on it as well. One happy Californian.;)

This is a good time for me to thank Ian, Bo, Widget and Ken for baiting the trap with their mouth watering descriptions of the virtue of this once under the radar speaker, the 4345. And to Subwoof for chosing me as the next caretaker, curator actually, of his wonderfully restored pair. But most of all to Greg Timbers for his thought and work in bringing these into existence.

Please excuse any spelling errors, I am really excited.

Clark in Peoria

[speakerdave]

They're here:

[Mr. Widget]

So the 4333s weren't big enough for ya?:D


Widget

[speakerdave]

Thanks. Yeah, this size seems like a natural to me.

David

[4313B]

The network components should be updated and this isn't easy. All the capacitors should be polypropylene and you would want to use air core inductors where ever possible. I believe the 4345 used some tapped iron cores. Those are hard to replace with aircores because the surrounding network topology would have to change and all of the values have to be re-engineered. I would suggest leaving them alone unless you are really good at this stuff.

If you can swing it, go to a biased network. The difference is unbelievable.As we discussed in your office I have one pair of 4344's and one pair of 4355's that are getting the non-tapped autotransformer versions of the filters you helped me redesign several years ago. I believe one forum member is seriously considering doing a pair of 4345's as well. Thanks once again for those voltage drives along with the tapped-autotransformers for measurements. Several other members have asked for the schematics and I will make them available once I finish one pair of each of the networks. For those who are interested in how to model tapped autotransformers David Smith also played a key role by graciously providing the tapped autotransformer model and matrix found at this link - Tapped Autotransformers (http://audioheritage.org/vbulletin/showthread.php?t=5376)

Everyone that has done biased networks has responded very positively. I personally think they're great. :)
My sad, dead misbegotten thread seeking comparisons between the 4345 and the 250ti did not live and die in vain. As only one of the members voicing curiosity about some of the most beloved designs JBL has graced the faithful with, I add my heartfelt thanks to Mr. Timbers for presenting his take on the situation.Yes, thank you Greg for including the 250Ti as per my request. Like I mentioned, the number of questions are probably endless but any time you can drop by and knock one or two out it is genuinely appreciated by virtually every single reader of this forum. The significance of your participation is staggering. As Don can attest, I've often expressed my hope that you would be able to find the time. This is truly fantastic! :)

[4313B]

They're here:Very nice Dave! They look great. :)

[boputnam]

Yeah, this size seems like a natural to me.Good grief, speakerdave!! Cool succession plan, dood! Wow. :applaud:

But lookie - those 2245H's have already dislodged your preamp! :rotfl:

I'll be excited to know your thoughts after getting an EQ into the signal path, if that's the plan. And, I'm sure either Widget or myself could be talked into making a run up there with some test gear, if you're in-need.

Have SmaartLIVE (http://www.siasoft.com/), will travel... :scoot:

[4313B]

Good grief, speakerdave!! Cool succession plan, dood! Wow. :applaud: No joke huh!? :rotfl:

Well played.

[johnaec]

They're here:Congratulations, Dave! :applaud: 'Guess instead of your coming by for a listen of my XPL200's I should be going to your place for a listen! What kind of beer do you like? ;)

John

[Ken Pachkowsky]

No doubt you will enjoy them. Having been the previous owner of a members pair, I still suffer from 4345 envy. I wish I could own many systems.

GT, that was a great read. Thanks for sharing. I don't think anyone would have expected such a detailed and forthcoming post. As for the interest in your "old technology", good engineering is timeless. In some ways, we long for the days that were.

Thanks for your generosity.

The Forum

[schloerch]

They're here:

A little contribution from germany-they work well here!

[Mr. Widget]

Cool...

I like the cabinet work. Are these DIY home brews or did you reskin a pair of factory made 4345s with an additional layer of plywood and front trim?


Widget

[JuniorJBL]

Thank you all for the interest in my work. I must admit I have been blessed with a really nice profession that has treated me well for a very long time. Remember that sound and music enjoyment are very personal things and that what makes you happy may or may not please others. Screw them. If you are happy and no one is geting hurt then go for it. No loudspeaker system even approaches real life so there is plenty of room for interpretation.

You say thank you, but, we here on the forum scream "THANK YOU GREG!!":applaud: For giving us all these wonderful things to listen to and enjoy!!

Thanks again Greg!!:D
Shane and LHF!!

[Ian Mackenzie]

There is a lot in Greg's post and it certainly put clarity around what we have here. Just what the doctor ordered.

Well this has all been a great reaction everyone

Keep the posts and dialogue happening.

For those who are wondering what the factory crossover is about, here is a glimpse.

cc Bo

[schloerch]

Cool...

I like the cabinet work. Are these DIY home brews or did you reskin a pair of factory made 4345s with an additional layer of plywood and front trim?


Widget
I am glad that you like it,Mr.Widget. These are original 4345's done with maple-wood;today I would prefer the original veneer, of course but anyway, they look very nice.

[Mr. Widget]

With retro grille cloth they would really look like some of the early JBL speakers... admittedly on steroids.:D


Widget

[speakerdave]

But lookie - those 2245H's have already dislodged your preamp! :rotfl:

Dammit, Bo!
:banghead:
I KNEW you were going to do that!


I'll be excited to know your thoughts after getting an EQ into the signal path, if that's the plan. And, I'm sure either Widget or myself could be talked into making a run up there with some test gear, if you're in-need.

That's a very generous offer. When I'm ready to make good use of that effort I just may take you up on it. For the time being, since I have to get off this merry-go-round to focus on another project, I will be biamping with the 5235. When I feel I can use the time necessary I have a pair of White EQ's and also will attempt to make some cards for the DX-1.

David

[speakerdave]

'Guess instead of your coming by for a listen of my XPL200's I should be going to your place for a listen! What kind of beer do you like?

Nay! We still must do both! I will not be able to take the time until August, so until then you must hang on to both pairs of those fine fourways.

David

[boputnam]

That's a very generous offer. When I'm ready to make good use of that effort I just may take you up on it. Cool. I'd like to see what differences there are from my room and signal path. I do gigs up north from Fairfax to Ukiah :blink: not infrequently, so it may not be too inconvenient for me when you are ready.

BTW, my role would be solely as technician, not as engineer. You can set whatever curve / response you desire - I just wanna help you measure it... :p

[Mr. Widget]

Drop me a line when this meeting of the 4345 minds occurs... I'd like to tag along.:bouncy:


Widget

[Don McRitchie]

With retro grille cloth they would really look like some of the early JBL speakers... admittedly on steroids.:D

That was my reaction too. They look like the Alvin Lustig designed systems from the early 50's. I quite like the look.

[hapy._.face]

That was my reaction too. They look like the Alvin Lustig designed systems from the early 50's. I quite like the look.

I agree- they look like Alvin Lustig designed cabs.
I think they're beautiful! I love the maple. I just wouldn't put Alvin's legs on them. :p

Nice job.

[Chas]

Congratulations Dave....we're gonna have some fun....:D

[boputnam]

This evenings resultant response curve, in FFT. Not bad.

Lpads at "0", except the midbass which is at "-1". Don't ask me why... :dont-know

Now, off to some red wine and a "4345 Session"... ;)

[boputnam]

I am glad that you like it,Mr.Widget. These are original 4345's done with maple-wood...I agree - I really like the look.

There are no mounts for grills - do they have grills?

And, the 2245H's lool to be the newer version, which confused me.

On L is 1980's vintage 2245H - on R is 2002(?) vintage 2245H.

Your's look like the newer vintage... Have you refurbished those 4345's?

[Mr. Widget]

Of course you really like the maple.... look at your floor. ;) :applaud:


Widget

[hapy._.face]

..and Bo's cat (or dog- a golden, I presume?) really loves this chair:

http://i13.photobucket.com/albums/a253/ameristalgia/95baeb7c.jpg

[boputnam]

You guys all suck...

:rotfl:

-----

But, you should both be here right about now. There's a Beaucastel '90 CDP that is begging for company. John Nebel - where ARE you...!! :)

[hapy._.face]

You guys all suck...

:rotfl:


:)

[Mr. Widget]

So, is it time to remove posts 62-66 before Ian notices...:blink:


Widget

[Ian Mackenzie]

Woof,:p

What you say?

Perhaps images of all the 4345 drivers (the whole internals) on polished floor boards would be nice. Something for the 4345 Gallery to come!

I am down with the flu so I can't talk..only woof

[schloerch]

That was my reaction too. They look like the Alvin Lustig designed systems from the early 50's. I quite like the look.

...how do you like me know?:blink: Telle me more about Alvin Lustig.

[speakerdave]

This evenings resultant response curve, in FFT. Not bad.
Lpads at "0", except the midbass which is at "-1". Don't ask me why... :dont-know

Thanks for the tip. My settings are close to that. My room is different from yours, probably smaller and better damped.


Drop me a line when this meeting of the 4345 minds occurs... I'd like to tag along.
Absolutely!

Chas, Ken, schloerch and others, thank you for the kind words. I will be reporting on progress when I can.

David

[Mr. Widget]

...how do you like me know?:blink: Telle me more about Alvin Lustig.Sorry Dave, Bo, and the rest... these maple cabinets are gorgeous!

Here is a link to some of the older JBLs that have a similar look to yours.

http://www.lansingheritage.org/images/jbl/catalogs/1957/page6.jpg


Widget

[hapy._.face]

these maple cabinets are gorgeous


yeah, I'm with you. I keep coming back to this thread just to look at them. I have to say- they're the prettiest 4345's I've seen thusfar. I'll even go so far as to say I think all the big monitors would look good in maple. That was an excellent choice- one I don't think I would have made- but after seeing it done I certainly would. Lovely.

JBL was so lucky to have Lustig. Alvin Lustig's style was effective, clean, bold, highly marketable, and he had an excellent grasp on 50's modern trend. There was a slight hint of playfulness to his work (especially his graphic design) that indicated the man sort of cranked it out in a gifted, effortless fashion. It's a common statement, but it's worth repeating: 'He was a natural born designer.' period.

http://www.alvinlustig.org/

I couldn't resist comment on a designer I admire- or on a pair of speakers I admire.
Alas, no more OT hijacking- carry on. Sorry.

[Ian Mackenzie]

I have been getting some pm requests for details of the 3145 crossover,what capacitors to use, details of the drivers for the 4345 (cloned) and odd ball question like can I use a 2440/2441 driver? Unfortunately I simply do not have time to answer a stream of ongoing questions and 99.99 % of it has been covered on the public forums to date.

There are volumes of good data on certain threads that you can refer to regards accurately building to the required 4345 technical specifications.

For example but not limited to:

http://www.audioheritage.org/vbulletin/showthread.php?t=314
http://www.audioheritage.org/vbulletin/showthread.php?t=952

Giskard has also posted numerous times details of the equivalent crossovers. My suggestion is you build a charge-coupled network using Solen capacitors. If there is sufficient demand and popularity we may open a thread on that topic. (I will be attending to my own CC network a a week or so!)

However, while I would encourage that imagination is more important than knowledge (..famous work words of Albert Einstein 1879-1955) you will need to do your own development if you decide to make substitutions on drivers.

If you have a question following a search about the original design post it in a thread covering your project as no doubt others will pitch up with a heads-up and the wider membership/spectators will benefit following your progess.

Now, just to see if you are awake, here is a quiz. The first poster to state the correct description of what the top and bottom diaphragm is (excluding moderators ..and Giskard please) in the attachment gets a mystery prize! Only one answer per poster thanks

Ian

[johnaec]

Now, just to see if you are awake, here is a quiz. The first poster to state the correct description of what the top and bottom diaphragm is (excluding moderators ..and Giskard please) in the attachment gets a mystery prize!Did you do the aquaplas yourself?

John

[Zilch]

From the red dots, both are D16R2425.

Bottom one has homebrew Aquaplas coating; factory don't coat the diamond surround, as I recall.

[Not that it's a bad idea, tho, of course.... ;) ]

[Ducatista47]

That's what I get for not taking my speakers apart more. I thought they were D16R2421's, without and with aquaplas.

Clark

[Ian Mackenzie]

From the red dots, both are D16R2425.

Bottom one has homebrew Aquaplas coating; factory don't coat the diamond surround, as I recall.

[Not that it's a bad idea, tho, of course.... ;) ]

Congratulations Zilch, you are the winner of the quiz!

I will contact Lord Zilchmeister early next week with details of the mystery prize.

Ian

[Zilch]

I thought they were D16R2421's, without and with aquaplas.Yeah, the titanium has a more "gunmetal grey" color to it (top in pic,) whereas aluminum looks more, well, ummm, "aluminum." :p


I will contact Lord Zilchmeister early next week with details of the mystery prize.


:bouncy:

[Ducatista47]

I just got some mp3's, Nero'd them up to wav files, equalized the volume with Nero's nifty tool and burned them to a disc for my wife's car cd. I previewed the cd on the 4345's.

I had suspected all along the big dogs would improve even the crappiest source material, and let me tell you it doesn't sound bad.;) The body is amazing, considering the source.

Moral of the story, if you want your tune collection to sound better, amps and electronics are part of the answer, but don't count out the 4345. Build or buy!

Clark

[Ian Mackenzie]

Well we were all having Fun here.

I like to keep people curious and interested when it comes for caring for and revitalising their JBL's.

Aquaplas is nothing new on the forums, nor is Charge-Coupling.

JBL have been using both for years. Certain aquaplas diaphragms can ordered from JBL. Details are all over the forums about Charge-Coupling.

I don't see anything exclusive about any of this stuff. If you can't improve an aging 30 year old system with published more recent ideas then you may as well buy current SOA stuff from them with all those new ideas anyway or start looking at the competition.

Every member who has heard or tried acquaplas treated diaphragms has either posted about or has it every reason to post about it. Both these technologies are a significant improvement.

About the above post. I have never read nor seen the above paragraph but now that you have posted it its public knowledge.

[Ian Mackenzie]

I will post some other amusing improvements shortly.

Here is another quiz but its a trick question this time.

Who's 4345's are these? Are they the same speaker?
There will another prize for the first correct answer.:applaud:

One post only per poster.

[Ian Mackenzie]

This is one of my 4345 clones.

I should point out that initially I was given the wrong JBL Blue paint by a certain member but they sure sounded great. They have since been re painted. How dare he!

One of my little to do jobs will be to re finish them with the exact baffle color match and make up some grill covers next week when I have some time off. I want laos to get some foilcals made-up and some nameplates.

Heck I may even make new enclosures one day..I have decided to make a 4345 Centre Channel. I have not quite worked it out yet but three 18 inch 2245 in one room is a very serious concept:eek:

[JuniorJBL]

I will post some other amusing improvements shortly.

Here is another quiz but its a trick question this time.

Who's 4345's are these? Are they the same speaker?
There will another prize for the first correct answer.:applaud:

One post only per poster.

It would appear that these were once owned by Ken And now are in Bo's front room!!

[Ian Mackenzie]

It would appear that these were once owned by Ken And now are in Bo's front room!!

Sorry, not 100% correct (I said it was a trick question..a clue..read Bo's posts on his ownership of these:) ).

[Zilch]

C'mon folks. Don't let me win again!!

Not being a 43xx "Club" member, I'm justa carpetbagger in this thread.... :p

[Ian Mackenzie]

C'mon folks. Don't let me win again!!

Not being a 43xx "Club" member, I'm justa carpetbagger in this thread.... :p

Oh come on guys ....

You may as well Zlch....I have not mailed the other prize yet!

[Ian Mackenzie]

Regards that other little noise I'll just ignore it.

[Shane Shuster]

I'll guess Bo's and they are technically not the same speaker.

[Ian Mackenzie]

Time for another hint.

Bo did a special thread about a _ _ _ _ _ _ of a cone.

He also performed other maintenance.

[Tom Loizeaux]

[QUOTE=gtimbers]"I can't belive all the interest in this 30 year old system."

Greg, Thanks gain for your post on the 4345.

Though the 4345 is popular with some members here, and the 4344 is the latest version (US) of the 434X series, the 4343 seems to be the most prevalent version of these great 434X series studio monitors. Since so many of us are using, restoring and refining 4343s, I wonder if you would comment on this 43 series in terms of how they differ sonically from the character and nuances of the 4345s you commented on earlier.
Specifically:
Are the 15" woofers better suited to the 10s and how do the 2231, 2231H and 2235Hs compare in this monitor. (Bi-amping a given)
Can you comment on the 2121 verses the 2122H in this application and how the inverted dust cap contributes.
And finally, which compression driver/ diaphragm fits into this 4-way configuration best?

There has been a great deal of interest and discussion on these points, and much good information expressed, but your comments are highly valued, for obvious reasons, and would make a great contribution to this Forum.

Thanks again for all your efforts!

Tom

P.S. I love my 4343s

[4313B]

make a great contribution to this Forum.

One last time:

Stock 4343
1. Bi-amp and build a biased bi-amp only 3143 filter
2. Aquaplas the 2420 diaphragm

Upgrade to 4344
1. 2231 => C8R2235
2. 2121 => C8R2122
3. 2420 => aquaplased D16R2421 or D16R2425 diaphragm
4. Bi-amp and build a biased bi-amp only 3144/3145 filter

[Ian Mackenzie]

Zilch,

When are you going to show us your new Threads??;)

[Ian Mackenzie]

[quote=gtimbers]"I can't belive all the interest in this 30 year old system."

Greg, Thanks gain for your post on the 4345.

Though the 4345 is popular with some members here, and the 4344 is the latest version (US) of the 434X series, the 4343 seems to be the most prevalent version of these great 434X series studio monitors. Since so many of us are using, restoring and refining 4343s, I wonder if you would comment on this 43 series in terms of how they differ sonically from the character and nuances of the 4345s you commented on earlier.
Specifically:
Are the 15" woofers better suited to the 10s and how do the 2231, 2231H and 2235Hs compare in this monitor. (Bi-amping a given)
Can you comment on the 2121 verses the 2122H in this application and how the inverted dust cap contributes.
And finally, which compression driver/ diaphragm fits into this 4-way configuration best?

There has been a great deal of interest and discussion on these points, and much good information expressed, but your comments are highly valued, for obvious reasons, and would make a great contribution to this Forum.

Thanks again for all your efforts!

Tom

P.S. I love my 4343s

Hi Tom,

About the 10 inch matching/mating I think its fair to say that you need to watch boundary effects with the larger woofer in the 4345 more so than the 4343 to ensure the system does not bloom in the bass and muddy the integration with the mid cone. This has been discussed elsewhere by Giskard and Greg.

There is also factual information on the 2121 vs 2122 in various threads posted by Giskard if you care to do a search.

You may wish to pm porschedpm who as I understand it has completed all the driver and crossover upgrades from the 4343 to 4344 for his comments on the subjective differences.

Since the crossover and Mid & Hf components were lifted from the 4345 (by another engineer) and used for the 4344 it is reasonable to assume they are tonally very similar in that regard (however the placement of the 15 inch driver in the 4344 was apparently not ideal).

Greg designed the 2245H and tuned the enclosure empirically for the 4345 system. Some details of this are given in Greg's earlier post.

As I understand it the 4343 was designed by another engineer(s).

Don may may be able to document more on this at a later stage.

Ian

[4313B]

As I understand it the 4343 and 2231/2235H was designed by another engineer(s).

Don may may be able to document more on this at a later stage.Don will have to elaborate. Greg has said that he didn't do the 4343 several times over the years. Mark Gander did the 136H/2231H and Greg did the LE14H-1 and 2235H, as well as the 2245H. I have no idea who did the 2121, never asked, but Greg did the 2122H.

[Ian Mackenzie]

Thanks for the tip. My settings are close to that. My room is different from yours, probably smaller and better damped.


Absolutely!

Chas, Ken, schloerch and others, thank you for the kind words. I will be reporting on progress when I can.

David

David,

Can you please post a picture?

[Ian Mackenzie]

I am proposing to build a black magic box for the 4345.

Inside it will have a dedicated active crossover for the woofer/midrange and a high pass filter for the slot. There will be a charge coupled passive network and a small chip amp for the slot.

It may sound complicated but with some thought I think it will be fairly straight forward.

I will post details as the concept develops

Ian

[Robh3606]

Now that sounds like a good idea! Combines several significant changes into one upgrade.

Rob:)

[Ian Mackenzie]

Now that sounds like a good idea! Combines several significant changes into one upgrade.

Rob:)

No doubt it could be applied to the 4344/4343.

My last back boxes.

The key will be to bring together and combine the essentials.

Pending space and budget I might add an X Aleph >75 watts for the mid + horn and and Mini Aleph <10 watts for the Slot for my personal version.

Ian

[Ducatista47]

I am proposing to build a black magic box for the 4345.

I will post details as the concept develops

Ian

You have my attention, Ian. I wish I knew enough to contibute.:(

Clark in Peoria

[speakerdave]

David,

Can you please post a picture?

Of the settings? Tomorrow.

I've moved the speakers into the larger room (only Widget has seen it, I think), and that has had a very rewarding result. The speakers are not tracking, so tomorrow I may steal the time to bring my audio generator in and juggle tonality and tracking for a while.

David

[boputnam]

The speakers are not tracking...This syntax is new to me. What are you describing...?

[speakerdave]

This syntax is new to me. What are you describing...?
All fixed. I hooked up my Krohn-Hite, set the preamp to mono and had my son turn the dial slowly, calling out the hundreds while I sat in the focus. It only took a few minutes, and I had them climbing straight up. Now when Anne-Sophie Mutter plays, the only movement in the imaging is her body sway. Yesterday she was walking back and forth behind the conductor as she went up and down the scales. Part of the problem was differential absorption and reflection of the upper mids in the fields of the two speakers. I usually like to sit back farther than the point of best focus because I like the blended sound more than the sharp imaging. So,when I sat on focus I found the tracking was better than I had thought and I only needed to make a minor adjustment to one level control.

David

[grumpy]

I'm thinkin' amplitude balance (L/R level tracking) vs. frequency was the point. -grumpy

[speakerdave]

I'm thinkin' amplitude balance (L/R level tracking) vs. frequency was the point. -grumpy

What he said.

[speakerdave]

Here they are in their new spot.

[Zilch]

I like the blended sound more than the sharp imaging.Rob's kinda saying similar over in "PT Waveguides."

Something more "natural" about a slighly diffused (defocused) image, is how I read it.

Also, somewhat more comfortable listening without a head brace.... ;)

[Ian Mackenzie]

David,

Thanks for the picture

This that a dang rocking chair I see yonda between them speakers.

Ian

[speakerdave]

David,

Thanks for the picture

This that a dang rocking chair I see yonda between them speakers.

Ian

'Tis, and that's where I am winters, by the fire, wrapped in a wool shawl. It just shows you how monstrously Brobdingnagian these '45's really are.

[boputnam]

It just shows you how monstrously Brobdingnagian these '45's really are.Yea, they dominate any room they are in - both sonically and physically! :applaud:

[Ducatista47]

A big, beautiful room and a big, beautiful pair of JBL's. Isn't life grand?

Since I aquired my pair, I am no longer seeking pinpoint imaging either. I like the way 4345's wrap you up and cuddle you in the sound field they generate. Perhaps they are unique in that respect; I haven't heard enough big speakers lately to know for sure. But it is the most satisfying presentation I have heard so far. Powerful, dynamic, subtle, even...assured. And very JBL. And somehow very inviting and friendly. And, oh yeah, thrilling. Not audio terms, but I tell it the way I hear it.:)

Clark

PS I'd better explain my setup. they are separated by only five feet and I sit only seven to ten feet back from the center. They are switched left to right, an old methodology that links the tweeters (slots here). I practically wear them. They sound really cool when I sit only five feet back, just before the imaging goes to hell. I always did like headphones!:D Actually, I move up or back depending on my mood. It's like having a variety of setups to chose from.

PSS If this seems strange, remember, they are monitors!

[Ian Mackenzie]

4345 Headpones anyone:applaud:

[Ian Mackenzie]

I am currently investigating some options for self powering the 2405 with in built active crossover/amplifer per Greg Timber's earlier post.

There are a couple of clever ideas on the table. I should have some details soon.

If you are interested, a show of hands would be welcome.

Ian


"The ring radiator hates passive networks. A major improvement in the upper range would be to drive the 2405 from its own little amp. You only need 3 or 4 v rms. The 2405 does 110 dB for 2.83v. It is padded way down in the system. There is little real power at those frequencies anyway. You only need to know the voltage output of the amp, power is irrelevant. The 2405 is about 12 ohms and won't draw much current".

[Chas]

Greg's comments interested me too. I was thinking that it would be nice to build some EL84/6BQ5 based amps for the job.

I still haven't got my 4345's up and running yet, so it will be a while before I can play with them.

Let's see what you have in mind, Ian.:)

[Tom Loizeaux]

Hey, I'm always interested in hearing about ways to make my 4343s sound their best!
Greg's comment about the 2405 certaily raises some questions. One of them being: Why didn't JBL ever make a tri-amp or quad-amp that would have driven their studio monitors to perfection?
I guess it's not up to us to decide if that should be done.

Tom

[Chas]

Hey, I'm always interested in hearing about ways to make my 4343s sound their best!
Greg's comment about the 2405 certaily raises some questions. One of them being: Why didn't JBL ever make a tri-amp or quad-amp that would have driven their studio monitors to perfection?
I guess it's not up to us to decide if that should be done.

Tom

My guess would be it's because inexperienced users would blow up the 2405. In a studio when they rewind or fast forward the tape machines, there is tremendous HF energy generated if someone forgets to lower the level in advance.

[Ian Mackenzie]

Greg's comments interested me too. I was thinking that it would be nice to build some EL84/6BQ5 based amps for the job.

I still haven't got my 4345's up and running yet, so it will be a while before I can play with them.

Let's see what you have in mind, Ian.:)

I am waiting on a request for some data.

When those details come to hand I will elaborate.

If you are astute and read carefully, I have already hinted at the approach in my recent posts.

Ian

[Ian Mackenzie]

Hey, I'm always interested in hearing about ways to make my 4343s sound their best!
Greg's comment about the 2405 certaily raises some questions. One of them being: Why didn't JBL ever make a tri-amp or quad-amp that would have driven their studio monitors to perfection?
I guess it's not up to us to decide if that should be done.

Tom

Its always interesting to speculate. Cost would be one reason and as I recall there were numerous customised offerings by third party studio designers and consultants during that era.

I propose to test the idea shortly as soon as I can finalise the details.

If its works to expectation and is practical, self amplification of the horn with built in active crossover will be a natural progression.

[Ian Mackenzie]

There are some obvious technical advantages but it will be interesting to measure the output of the 2405 direct coupled to a dedicated amplifier (I'll bet Zilch posts a graph by sunrise).

For example, most domestic / professional amplfiers are least linear at very low power levels. Meaning they don't sound very good at low power levels, particularly high frequencies.

Even with the UHF and HF transducers cranked back 10 db or more you are still talking only a watt or less of power for 95 db @ 1 metre in these systems. Under normal circumstances (unattenuated) the 2405 will produce 105 db and the 2307/2308 108 db @ 1 metre for 1 watt. However, as discussed above, its really a case of the level of voltage drive and not power that has to be understood.

Add to this the issues of the crossover capacitor (as we have been informed) and you have a receipe for dirty highs.

I have previously advocated class A amplfiers for the bi amping of the high section of these 4 way systems which by design eliminates these distortion issues at low power levels and is a subjectively obvious improvement.

It is intended that the 2405 with in-built active crossover/amplifer will be the next phase of improvement. Pending the outcomes we can consider similar duty for the 2307/2308.

Someone is bound to disagree but they probably gave up on listening to these systems a long time ago!

Ian

( I dont propose to outline the detail of the design here, that may appear in a dit thread at some point)

[Chas]

If you are astute and read carefully, I have already hinted at the approach in my recent posts.

Ian

Understood. I am still trying figure out how to design and build a good sounding active H/P xover at 290 Hz just to simply biamp mine - the LF isn't nearly as demanding IMHO, I plan to use my Ashley's for the low pass. I'd be interested to see what you plan for the 2405 in this regard. Maybe a third order passive in front of the amp would be the way to go? Not exactly good engineering, though.

I'm just thinking out loud, here.:blah:

[Zilch]

(I'll bet Zilch posts a graph by sunrise).Alas, no chip amp here. :(

But, it'll be interesting to see (hear) the difference between a regular amp and one of those.

Off to Parts Express, then.... :thmbsup:

[#300-952, 15W Stereo Class-T, $29.87]

[yggdrasil]

:thmbsup:

Will be following the progress with interest.

[speakerdave]

If you are interested, a show of hands would be welcome.

Me! Me!

[Ian Mackenzie]

Understood. I am still trying figure out how to design and build a good sounding active H/P xover at 290 Hz just to simply biamp mine - the LF isn't nearly as demanding IMHO, I plan to use my Ashley's for the low pass. I'd be interested to see what you plan for the 2405 in this regard. Maybe a third order passive in front of the amp would be the way to go? Not exactly good engineering, though.

I'm just thinking out loud, here.:blah:

Chas,

If you pm me I will sent you some design details.

About the 2405 I already have a very good 3rd order HP filter using a discrete low noise opamp.

The initial idea was to upgrade it as a high power opamp with enough bias current to driver the 2405 to 3 or 4 volts. Simple enough to do but I have not had time to look too closely at it this week. It woud be along the lines of the Borbely headphone amp. As a one off add on project I think it would be very interesting and fun!

But once you start to think about that you start looking at the bigger picture and I think that would happen soon after the 2405 update was done. I would like to give members the opportunity to discover for
themselves the true musical potential of these vintage systems.

Looking more broardly we have learnt from GT some of the weaknesses of these systems and some of the simple ways of dealing with them. I hope that Porschedpm will be able to publish an outline of his upgraded 4343 to 4344 project soon that includes many of these updates and a very high quality active crossover that I provided for analysis and subjective assessment. If Porschedpm's review is favourable in his system driven by a Passlabs X250 and X150.50 power amps I would be happy to a consider a limited diy active crossover from my kitchen table specifically for the 290hz crossover point. I have thought about it but I think quad amping is way too complex with cut and dried JBL designs like these that have been worked over as there are more gains to be had with simple improvements like charge coupling the passive crossover and improvements with better power amplifiers.

Ulimately a chain is only as strong as its weakest link and for this reason it is my firm view that Class A power amp operation is absolutely essential with the fine resolution and high sensitivity of the mid / horn and uhf transducers used in these systems. The intent of Charge Coupling is analogous to Class A amplfication and the benefits are subjectively and immediately obvious.

Unfortunately most consumer audio amplifiers are least best at low drive levels and this manifests itself as a loss of resolution and sonic glare in the upper midrange and highs.

Unfortunately the larger 800 hz exponential horn and lense used with the 2420/2421/2425 in the less complex 43XX systems is renown as one of the worst offenders of abrasive signal content. The shorter 2307 horn with 2308 used in the JBL 4343, 4344 and 4345 is a far better candidate and when paired with a Class A amplifier the issues are not nearly as apparent.

When you employ all these improvements the subjective enhancements are cascaded and it is hard to imagine how you could ever endure going back to the stock system.

Frankly I think there is more fun and enjoyment to be had from carefully enhancing these systems than shelling out very serious amounts of money on the lastest hardware.

Ian

[andresohc]

I would love to get into this too as I build my psuedo 434X mutant Home theatre system.

[Ducatista47]

Ian, scratching up the money and time to build/install are the only boat anchors for me. My interest is always keen for your 4345 mods, but so far I haven't gotten to even disabling the biamp switch. Bear with me, but boy is my hand raised.
Not as handsome as Speakerdave's furry hand, though.

Clark

[porschedpm]

.... I hope that Porschedpm will be able to publish an outline of his upgraded 4343 to 4344 project soon that includes many of these updates and a very high quality active crossover that I provided for analysis and subjective assessment....


I’ve been invited by Ian Mackenzie to publish an outline of the upgrades that I’ve made to convert my 4343’s to 4344. And give my impressions of the resulting sound. This 2 ½ year upgrade process has culminated with the recent addition of custom built active and passive crossovers built specifically for my application by Ian. I cannot brag enough about these crossovers. They bring out the best of both the speakers and the components upstream. The quality of the crossovers you chose to use really can make or break your system. The outline for these upgrades and my listening impressions can be found at the 4343-to-4344 upgrade thread at:

http://www.audioheritage.org/vbulletin/showpost.php?p=117384&postcount=228

Before anyone discounts these upgrades because they relate to mere mortal 4343’s converted to 4344 spec, and not to the highly venerated 4345’s to which this thread/club are devoted, let me just state that many of the upgrades suggested for the 4345 by GTimbers in post #27 earlier in this thread have been followed as part of the 4343-to-4344 upgrade process. Specifically:


Eliminating the bi-amp switch.
Bi-amp the speakers.
Updating the crossover networks.
Eliminating the L-Pads.
Making sure all upgrades are reversible so as to not impair resale value.
Of course the upgrade process also included replacing every driver in the cabinet, with the exception of the 2405, with the drivers specified for the 4344. There is also detailed discussion about uprading the crossovers. So if you’re interested in how this all came out and how it sounds, I invite you the link over to the 4343 to 4344 thread.

[Ian Mackenzie]

Hey Ed,

I asked for just a few lines....not the ten commandments.

Thanks again for sharing this.

Ian:)

[Ian Mackenzie]

Okay,

It looks like Ed wants to go top shelf so it might have to be one of these.

This particular amp is a mini class A power amp with some similarities to the amps Ed is already using in his system. Ideally, all amps in the mid and high registers should be of identical design/type so this may be a precurser to other things!

Ian

[Ian Mackenzie]

I am organising parts for this project at the moment, something should emerge in a next few weeks!

Ian

[John W]

I will soon be building a bi-amp only version of the 4345 with Giskard's equivalent 3145 network.
I saw some earlier posts suggesting it was ok to remove the 3db lpad on the 2122H and add a 10 ohm zobel, like the picture below.
Has anyone tried something similar, and do you need to compensate the HF and UHF networks to account for the 3db difference? It only looks like there is +4db available on the lpad adjustments to begin with.

[Ian Mackenzie]

John,

Hi, I have not attempted this alteration but plan to soon.

What you have said appears correct. There will be only +1 db of adjustment on the horn and slot.If you are looking at the new equivalent you could mess with the fix attenuation using 10-11 ohms to model the new values.

Ian

[Ian Mackenzie]

Some parts arrived so I will start work on Slot energiser soon

Ian

[Ducatista47]

http://www.audioheritage.org/vbulletin/showpost.php?p=117384&postcount=228

Before anyone discounts these upgrades because they relate to mere mortal 4343’s converted to 4344 spec, and not to the highly venerated 4345’s to which this thread/club are devoted, let me just state that many of the upgrades suggested for the 4345 by GTimbers in post #27 earlier in this thread have been followed as part of the 4343-to-4344 upgrade process. Specifically:
Eliminating the bi-amp switch.
Bi-amp the speakers.
Updating the crossover networks.
Eliminating the L-Pads.
Making sure all upgrades are reversible so as to not impair resale value.
After reading this post again, I am reminded of my initial impression of Mr. Timbers' post. I thought immediately how very many JBL designs - pretty much almost all the speakers we most covet - would benefit from the suggestions made to improve the 4345 and the 250Ti. The slot had a (fifty year?) production run, L-pads are a fixture of JBL baffle boards, all crossovers have room for improvement, etc. etc. I see opportunity everywhere, at least back to the sixties.:applaud:Think of an upgraded S7. Makes my mouth water. Hmm, I wonder if ring radiators would benefit from a chip amp? I always loved the S8R.

Clark in Peoria

[Ian Mackenzie]

Initial impressions of charge coupled unbypassed equivalent network.

http://www.audioheritage.org/vbulletin/showpost.php?p=124237&postcount=80

[Ian Mackenzie]

To CC or to not CC..I don't know YET;)

http://www.audioheritage.org/vbulletin/showpost.php?p=124620&postcount=87

[Major Petty]

Well, the rest of us do so feel free to follow our lead...

or not... it apparently takes all kinds to fill the freeway.

I'll bury a version of the DD66000 white paper for everyone as promised for 13 SEP 2006 in this thread. It runs charge coupled Solen capacitors and it "works" just fine. Note the references (yet again) to the biased capacitors in this white paper. Be mindful that the gear associated with running something like a DD66000 is usually pretty "top end". In other words, leave the Marantz 2230B for the L16 Decades... scale as necessary for a 4345...

You know the drill - Right Click - Save Target As...

Have a great day!


The DD66000 quite simply provides the most musical experience of anything in our history.

- Agreed. Fantastic accomplishment. Stunning performance. A perfect 60th Anniversary Statement.

[hjames]

Hey - thanks bunches!
Great stuff to study, even for those of us with a lesser budget!
Talk care!

[Ian Mackenzie]

If the truth be known it probably makes the ambiguous Japanese amplfier sound listenable, at least 95 % of them that are chip amps in some way or another.

The thing is the 4345 does not need CC network to sound good and there are no electro capacitors in the stock networks.

Its always been my understanding and that of many loudspeaker engineers as published in many well regarded text books that electros are not the preferred variety.

http://www.audioheritage.org/vbulletin/showpost.php?p=123850&postcount=37

[yggdrasil]

Hi Ian

Regarding the active crossover you are looking into - if you are looking at discrete opamps, this could be an idea.

I have been playing with the thought of a small power opamp at the output of the crossover. This could be a variation of the MOX.

This one is biased at 0,3A, which should at least be enough for the slot, maybe even the CD.

[Ian Mackenzie]

Yes,

That is a possibility, the Fet follower adds current gain.

The Borbely headpone amplifier is similar.

Give it a try.

regards

Ian

[yggdrasil]

I will, but a little different. Was not able to get the 2SK389 at a reasonable price. Had made a deal with some chinese, but they turned the price way up after receiving my money.

I have several other dual JFET's to try, a couple of MOSFET's and a couple of BJT's. Will try with higher rail voltages as per NP's advice.

Hope to get i playing before christmas...

[Ian Mackenzie]

Pm me your details and I will mail some 2SK389s for you to try.

best

Ian

[Ian Mackenzie]

Please note the slot energiser black box is still on my list but there has been a delay due to some renovations here at home.

I propose to make the black box using a diy X Aleph and include a Mox hi pass filter. The reason for going this route is I prefer to use identical amplifiers for mid and HF and this design is easily scaleable.

[Ian Mackenzie]

http://www.audioheritage.org/vbulletin/showpost.php?p=125183&postcount=109

[Ian Mackenzie]

Here is a link to an interesting modification

http://www.audioheritage.org/vbulletin/showpost.php?p=126848&postcount=153

Over time I have also tried different placement postions and have found elevating the system on a stand about 8 inches off the floor can help with balance pending you room dimensions.

Ian

[Ian Mackenzie]

news

http://www.audioheritage.org/vbulletin/showpost.php?p=129259&postcount=194

[Chas]

Ian, I hope you don't mind me posting this here, but I think it is relevant. Please feel free to have the Moderators move it.

Now that my 4345 restoration is complete, I have upgraded all the internal capacitors necessary for biamping, bypassed the switch and along the way, bi-wired the MF and HF/VHF. Lately, I have been thinking about something Greg Timbers mentioned in his 4345 "You Guys are Amazing" post.

By the way, the results to date, are nothing short of amazing. :)

What I am concerned about - and the reason for this post, is Greg's comment about the 2245 and 2122 drivers not having flat response at the crossover frquency (290 Hz) when bi-amping the 4345.

I am using L-R 24dB/octave at 290 Hz and it sounds fine but I have yet to run my RTA and actually see what is going on. I have changed the polarity of the high pass signal so that all the drivers are the same polarity as the 2245 and there was a huge improvement. I guess that makes sense due to the original passive network being 12 db/octave.

Has anyone addressed this issue? My understanding is that the JBL active crossovers were standard third order (18 dB/octave) and there was no other signal manipulation. What gives?

Charles.

[boputnam]

I have changed the polarity of the high pass signal so that all the drivers are the same polarity as the 2245 and there was a huge improvement. Describe the result?


My understanding is that the JBL active crossovers were standard third order (18 dB/octave) and there was no other signal manipulation. Yes, the 5234a has 4345 specific cards with a -18dB slope. I have wondered about the difference between the two slopes myself. I have no clear explanation of why they were so different except I understand the 5234a was done on a "best efforts" basis.

[Chas]

Hi Bo. Just so I am not misunderstood, I have positive going signal on the low pass side attached to the black terminal on the 2245's. Now, if you look at the 3145 schematic, the positive signal is reversed to all the rest of the crossovers feeding everything above. I think this was bcause the slopes are 12 dB/octave with the attendant 180 degree phase shift. Strictly a guess here on my part...:o:

In my case, I simply reversed the high pass network input (actually I did it at the amp), since a L-R fourth order network does not have the same issue.

The effect was to bring everything together in a more homogeneous way. It definitely improved imaging as well. I haven't tried returning to the previous polarity, I'll give it a try, when I have time just to be sure I wasn't hearing things.

[boputnam]

Hey, Chas...

Yea, I understood that. Interesting. I too would be keen to know if the previous polarity was so different - with all the changes you've made it gets complicated attributing improvement!

[Mr. Widget]

In my case, I simply reversed the high pass network input (actually I did it at the amp), since a L-R fourth order network does not have the same issue.
Do you know if both amps you are using invert phase or are non phase inverting? This is something that always needs to be kept track of in a multi-amp situation. Obviously it is a non issue wen you are using multiple identical amps.

Bo, we did some EQ tweaking near the crossover frequency on your system when we were setting up your Bryston 10B... I don't remember what we did or the slope of the Brytson, but if you could add those data points to Chas's discussion it would be interesting.


Widget

[Chas]

Do you know if both amps you are using invert phase or are non phase inverting? This is something that always needs to be kept track of in a multi-amp situation. Obviously it is a non issue wen you are using multiple identical amps.

Widget

Agreed. All my amps are noninverting. While the polarity issue is interesting and may certainly pertain to the entire 434X family of monitors when moving from internal passive to biamping with a fourth order network, my interest is primarily with Greg's comment about FR at crossover.

When I have some time, I'll run the RTA and see if there is something there that's measurable. Robh, you've been fooling with this sort of four way set up for a while, have you noticed anything and care to chime in?

[Ian Mackenzie]

Chas,

Yes it is quite confusing when talking absolute polarity.

I recall a while ago comparing the 24 LR slope and I got a similar reaction to you. It works better running both the woofer and mid section postive to positive on both the high and low was amps.

According the the LR filter theory it works better in absolute phase.

If you have the luxury of eq at the crossover point I think you could propably get a similar audible result using different filters.

The 18 db is definately more abrupt and more sensitive to setup. If you like the 24 LR filters in phase then sit back and relax. I also found the boundary effects, room modes and box location quite critical to obtaining a satisfactory midrange transition and you can kid yourself one filter type is better than another with all this. I currently have my system elevated and de coupled some 8 inches off the floor.

At the moment I am trying 12 db LR slopes and will advise on this soon on the result. I also like the XP 200 cards for the 4345.

By the way the 3145 stock network introduces significant insertion losses into either biamp or full passive mode so you are best to bypass the switch completely.

[Zilch]

When I have some time, I'll run the RTA and see if there is something there that's measurable.Nearfield (1/4"), you'll be able to document the performance of the individual drivers.

At that frequency, I don't know how to get the summing absolutely other than ground plane, but some compromise position between the drivers seems to give a reasonable approximation....

[Chas]

Nearfield (1/4"), you'll be able to document the performance of the individual drivers.

At that frequency, I don't know how to get the summing absolutely other than ground plane, but some compromise position between the drivers seems to give a reasonable approximation....

Cool, I'll give it a whirl, Zilch. Hey, I'm new to this RTA stuff, what level pink noise do you run at?

[Zilch]

That close, you gotta dial the SPL way down so as not to overload the mic and input. It'll sound like a whisper from normal distance. Takes some experimentation to get into the normal reading range. Start low. I use -10 dB for nearfield, typical.....

[Robh3606]

Hello Chas

What kind or RTA do you have?? I have an Behringer 8024 and what I would do is set it up 1- 2 meters away and use pink noise. You can easilly see what the correct polarities are by the suck out at 300Hz when they are not correct. With the 4344's when I was running the M552 with 24dB slopes I had all the drivers in phase. I am using the DX-1 with 12dB slopes now and have the 2235 out of phase with the rest of the drivers like the original crossover.

Rob:)

[Chas]

Hello Chas

What kind or RTA do you have?? I have an Behringer 8024 and what I would do is set it up 1- 2 meters away and use pink noise. You can easilly see what the correct polarities are by the suck out at 300Hz when they are not correct. With the 4344's when I was running the M552 with 24dB slopes I had all the drivers in phase. I am using the DX-1 with 12dB slopes now and have the 2235 out of phase with the rest of the drivers like the original crossover.

Rob:)

Behringer DEQ2496. Thanks for your input, Rob. Did you notice anything funky at the LF/MF crossover point when using fourth order (or other) filters? Nice to see that your experience matches what I am hearing.

I have a university student studying directly upstairs from my listening room,:( so I'll have to wait until the weekend before I can give the RTA a try.

I am still intrigued by GT's comment about the LF/MFfilter design, he mentioned it would have to be non-standard. :dont-know

[richluvsound]

Hi Chas,
thanks for post suggesting that perhaps that I could post a thread to document the build of my 4345's. I had thought about it before and your reguest finally gave me the courage to do so.
I started out wanting to build the L 300 , the first JBL's I ever heard.
I lived in Canada for 20 years so I grew up with a taste for warm snapping bass and crisp ,vapourous highs.I spent 10 years as a DJ in Edmonton surrouned by JBL and BJW. I have fond memories of the after parties that took place when the punters had gone home and I could just sit on the dance floor and listern to the music I loved.
Anyway , I moved back to England to Study Art and now live and work as profesional artist in London. I have 2000 ft2 studio ,so some weedy little bose
satalite system just aint gonna do it. I listern to music from when I wake up until I go to bed ( itunes).I spend alot of time alone painting ,so my sound is by bestfriend.

So yeah! I stumble across this forum and I have'nt looked back since.I did have a little fling with Klipsch. They were a nice sound ,but not for me .They made my ears tired after short time of listerning to them.
There is just something about JBL that keeps me coming back. I'm not a E.E
so I can't justify the attraction with graphs and equations. They sound moves me thats all can say .
There are some very talented people on this site and they know the theory inside out.But, one thing shines through stonger than the facts and figures , and thats ..... PASSION!
I have been given all the support one needs to tackle a project like this, without which, I'd still be dreaming instead of building.
Guido is doing all the electronics and reconing and I'm building the boxes. I will ask Guido to post his progress as well.
I just tried to upload some picks ,seems I need to resize the files. so i'll have to ask for help on this too !
Rich

[Guido]

Hi Rich

Look here for picture posting advice:
http://www.audioheritage.org/vbulletin/showthread.php?t=817

Why don't you start a own thread?

You should have the first packages by the end of this week.

[Chas]

Hi Rich and welcome. I look forward to hearing about your progress. 4345's ought to be just the ticket to fill 2000 cu. ft.!
Charles.

[JMD]

Hello to everyone, :wave:
The Slovakia in the middle Europe has big concentration JBL 4345

I've bought tree pairs of studio monitors from National Radio in Slovak Republic. I'd like to ask you to tell me if these serial numbers are corect:

Se. No.: 12759 - JBL 4345
Se. No.: 12690 - JBL 2245H
Se. No.: 15539 - JBL 2122H
Se. No.: 14891 - JBL 2421B
Se. No.: 11106 - JBL 2405H
+
Se. No.: 12676 - JBL 4345
Se. No.: 12844 - JBL 2245H
Se. No.: 15449 - JBL 2122H
Se. No.: 14203 - JBL 2421B
Se. No.: 11587 - JBL 2405H
___________________________________________

Se. No.: 12675 - JBL 4345
Se. No.: 12052 - JBL 2245H
Se. No.: 15535 - JBL 2122H
Se. No.: 14389 - JBL 2421B
Se. No.: 11593 - JBL 2405H
+
Se. No.: 12775 - JBL 4345
Se. No.: 13967 - JBL 2245H
Se. No.: 15509 - JBL 2122H
Se. No.: 14948 - JBL 2421B
Se. No.: 11137 - JBL 2405H
___________________________________________

Se. No.: 12631 - JBL 4345
Se. No.: ? - JBL 2245H
Se. No.: 14693 - JBL 2122H
Se. No.: 14226 - JBL 2421B
Se. No.: 10248 - JBL 2405H
+
Se. No.: 12752 - JBL 4345
Se. No.: 15217 - JBL 2245H
Se. No.: 14574 - JBL 2122H
Se. No.: 14846 - JBL 2421B
Se. No.: 11082 - JBL 2405H
___________________________________________

My frieend has bought next two pairs fo monitors:

Se. No.: 12475 - JBL 4345
Se. No.: ? - JBL 2245H
Se. No.: ? - JBL 2122H
Se. No.: ? - JBL 2421B
Se. No.: ? - JBL 2405H
+
Se. No.: 12637 - JBL 4345
Se. No.: 13929 - JBL 2245H
Se. No.: ? - JBL 2122H
Se. No.: ? - JBL 2421B
Se. No.: ? - JBL 2405H
___________________________________________

Se. No.: 12756 - JBL 4345
Se. No.: 12682 - JBL 2245H
Se. No.: ? - JBL 2122H
Se. No.: ? - JBL 2421B
Se. No.: ? - JBL 2405H
+
Se. No.: 12612 - JBL 4345
Se. No.: 13712 - JBL 2245H
Se. No.: ? - JBL 2122H
Se. No.: ? - JBL 2421B
Se. No.: ? - JBL 2405H
___________________________________________


Thanks


Bohdan

[Mr. Widget]

The Slovakia in the middle Europe has big concentration JBL 4345

I've bought tree pairs of studio monitors from National Radio in Slovak Republic.So that's where they all went... :bouncy:

Thanks for checking in and letting us know. Maybe someone here will be able to tell you about the serial numbers, though I expect that like most of JBL's historical record the Northridge earthquake may have taken this from us as well.


Widget

[boputnam]

The Slovakia in the middle Europe has big concentration JBL 4345...:shock:

Holy-smokes. I am speechless. Golly-gee-whiz.

- How did they find their way there?
- Where were they, before?
- What condition are they in?
- Have their drivers been refurbished?
- Can you PLEASE post many pictures!!?? :bouncy:

Now, I really know where Disneyland is.

[JMD]

Hello Boputnam

All pairs the JBL 4345 are complete originate - original speakers. Monitors are in good condition. One pair JBL 4345 I'm using at home in the Bratislava capital of Slovakia (60km near the Vienna capital of Austria). Next pairs needs repair of foam surrounds (Bass and Mid-Bass).
The monitors originate from government purchase at early 80th to the National Radio in Czechoslovakia (like BBC in GB). This monitors was used in professional recording and broadcast studios.
Sorry, actually I have only these two pictures:

http://jmd.szm.sk/Audio/Loudspeakers/JBL4345.jpg

http://jmd.szm.sk/Audio/Loudspeakers/18palec.jpg

Sorry my English is rather poor and I apologies for it.


Bohdan

[caladois]

Excepted the cones, they looks very good.

[spwal]

great pictures! your english is fine! welcome to Lansing Heritage

spwal


Hello Boputnam

All pairs the JBL 4345 are complete originate - original speakers. Monitors are in good condition. One pair JBL 4345 I'm using at home in the Bratislava capital of Slovakia (60km near the Vienna capital of Austria). Next pairs needs repair of foam surrounds (Bass and Mid-Bass).
The monitors originate from government purchase at early 80th to the National Radio in Czechoslovakia (like BBC in GB). This monitors was used in professional recording and broadcast studios.
Sorry, actually I have only these two pictures:

http://jmd.szm.sk/Audio/Loudspeakers/JBL4345.jpg

http://jmd.szm.sk/Audio/Loudspeakers/18palec.jpg

Sorry my English is rather poor and I apologies for it.


Bohdan

[Mr. Widget]

great pictures! your english is fine! welcome to Lansing HeritageDITTO!

Those are beautiful. I assume that getting them properly reconed or refoamed in Slovakia may be difficult. You may want to try to do a refoam yourself before going to a full recone.

Check out this thread:

http://www.audioheritage.org/vbulletin/showthread.php?t=469


Widget

[hjames]

That is VERY VERY cool - the Big 'uns!
JBL fans and collectors are EVERYWHERE!

[richluvsound]

Congratulations,

What an entrance ! what a find. They would fetch a heck of a lot of money in Russia.
Between you , and your friend ,you have 5% of all production of that monitor.:p

Rich

[Fangio]

5 pairs?? Awesome.. the pair shown looks quite unmolested cosmetically. Nice pics, keep them coming..

In particular pics of the original installation at the National Radio studios might be of interest for this site - do you by chance have access to some? And are the grilles & lenses present also? Oh, and welcome to the LH forums from here too. :)

[pos]

Between you , and your friend ,you have 5% of all production of that monitor.:p

There were only 100 pairs ever made?? are you serious?

[richluvsound]

Pos,


thats what I heard. Perhaps someone else could chip in with fact !

Rich

[spwal]

Not to digress, but 4341 short production life probably means limited numbers as well right?

[JBL 4645]

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=31064&stc=1&d=1203445293


Oh yeah I can hear those super highs above 20 KHz! :D

Still can’t get over the shear size of those and placing nipper in the middle shows the scale of the JBL4345 I think he has a future in JBL advertising.:p

[Rolf]

JBL 4645: You don't own these speakers. Nor do I. So why comment in this thread? I don't. I only got the 4343B's.

Don't like to get in here, but:

Please keep your comments to what you have an idea to talk about.

END

[Ian Mackenzie]

That was a nice picture.

Welcome.

Fangio, use the ignore button.

[richluvsound]

Does that work ? I mean, if you put someone on your ignore list it deletes their post from any thread you happen to be READING ?

[hjames]

Does that work ? I mean, if you put someone on your ignore list it deletes their post from any thread you happen to be READING ?
No, IGNORE simply sets the site to not display the contents of posts from those on your ignore list. You see their name and date, but the contents (and images and such) doesn't display. I find it annoying, but less annoying than the alternatives
:applaud:

[cooky1257]

Great score!
Are these new photo's of them at home or actual archive photos of when they were used to torture small children in Slovakias darker times;-)
Jokes aside apart from the foams they look in fabulous condition.
Frank

[JMD]

Thank you everyone for welcome.
Unfortunately I haven’t pictures of original the JBL installations from Slovak National Radio. But I will try get them.
Lenses are missing on all pairs. Is it a fail? I think their function is only lateral acoustic dispersion.
I have only two pairs completed grilles. But one pair grilles are broken. One pair has repaired foam on bass and mid-bass. This pair I use at home. Repair kit for foam surrounds I have bought in http://www.audiofriends.nl/speakerfoam/en/
Some pairs of these speakers were repaired 20 years ago (bass and Mid-bass). Speaker repair - recone was made in authorization service the H-PRO for the Czechoslovakia. Speakers repair – originaly recone in our country is cheap. Two bass and two mid-bass about 600€ in autorization service JBL.

Bohdan

[yggdrasil]

Lenses are missing on all pairs. Is it a fail? I think their function is only lateral acoustic dispersion.

The lenses's function is better dispersion. And, yes you want them.

Fantastic score.

Keep us posted on your impressions.

[JMD]

I have found pictures from Hifi meeting “Brnensky Podzim 2007” in the city Brno {Czech republic}. Here my JBL 4345 had standing ovation.

http://taylor.sk/coques/Site/HIFI.html (http://taylor.sk/coques/Site/HIFI.html)

cca 50 Hifi fans;)

Audio system:

sources:
Mark Levinson
Krell
Pioneer
TEAC DV50

amplifiers:
Audio Research D400
Krell
Mark Levinson
Vincent

Loudspeakers:
JBL 4345
ARC 300
Quadral Titan Mk.V
Quadral Titan Mk.IV
Isophon

[JBL 4645]

JBL 4645: You don't own these speakers. Nor do I. So why comment in this thread? I don't. I only got the 4343B's.

Don't like to get in here, but:

Please keep your comments to what you have an idea to talk about.

END

Rolf

I’ve heard them at Rich’s home last year on Tuesday 26th of July 2007 and I liked the uniform sound from the large 18” sub bass though to the 10” isn’t it, then on upwards to mid high then the super high but I’m a little older now I don’t have the hearing range that I once had when I was young.

No, IGNORE simply sets the site to not display the contents of posts from those on your ignore list. You see their name and date, but the contents (and images and such) doesn't display. I find it annoying, but less annoying than the alternatives
:applaud:


But if you’re not logged onto the site you can read the whole post because your not yet logged into the JBL forums.

[richluvsound]

JMD,

that was brilliant . Thank you for posting it. :applaud:

Rich, 4345 nut and fellow Mac monkey

[JMD]

... http://www.brnenskypodzim.ic.cz/program.html ... (czech language) ...

Where will buy lenses (2 to 10 units) for JBL 4345 in the Europe? ...with the exception of authorization services.

Please, exist archive of measurement protocol for concrete loudspeaker?

Bohdan

[speakerdave]

... http://www.brnenskypodzim.ic.cz/program.html ... (czech language) ...

Where will buy lenses (2 to 10 units) for JBL 4345 in the Europe? ...with the exception of authorization services.

Please, exist archive of measurement protocol for concrete loudspeaker?

Bohdan

"Please, exist archive of measurement protocol for concrete loudspeaker?"

Are you asking for published response graphs for this specific speaker (4345)? If so, I'm not aware of any.

The Model 2328 diffractor plate lenses are no longer available new, and are just that hard to come by that a Japanese craftsman has made reproductions. The originals show up on ebay with some regularity, but tend to get bid up. $200/pair is not unheard of. Even though the lenses are "just" for increased horizontal dispersion, you do want them, because without them the energy of the treble horn is too concentrated. The speakers sound better with them.

David

Edit: I take it back. Here's a 4345 response graph here, posted by the speakers' designer, Mr. Greg Timbers:

http://www.audioheritage.org/vbulletin/showthread.php?t=10613

[boputnam]

Are you asking for published response graphs for this specific speaker (4345)? If so, I'm not aware of any.There is a whole lot of technical info in the System Information - 4345 thread, including system response and voltage drives.

Good old Techbot - we owe a great deal to his diligence. :yes:

[Rolf]

I have found pictures from Hifi meeting “Brnensky Podzim 2007” in the city Brno {Czech republic}. Here my JBL 4345 had standing ovation.

http://taylor.sk/coques/Site/HIFI.html (http://taylor.sk/coques/Site/HIFI.html)

cca 50 Hifi fans;)

Audio system:

sources:
Mark Levinson
Krell
Pioneer
TEAC DV50

amplifiers:
Audio Research D400
Krell
Mark Levinson
Vincent

Loudspeakers:
JBL 4345
ARC 300
Quadral Titan Mk.V
Quadral Titan Mk.IV
Isophon

Hi. I had the Titan MK.IV, and my brother had the MK.V for some years ago.

I am very interested in the opinions on how they sound compared to the 4345.

Please let me (us) know.:bouncy:

[JMD]

Hi David,
Thank you for information about lenses, the model 2328.
Do you think, lenses could balance humps of frequency response in range 5kHz to 12kHz? This anomaly come with time delay of acoustic signal from high frequency driver. High driver location is deeper than UHF driver.

If I understand the JBL 4345 were sold without measurement calibration record?

Bohdan

[JMD]

Hi Rolf,
Sorry my English vocabulary is rather poor. I can't describe sound compared. Anyway I don't remember that some loudspeaker has award standing ovation. Except concert's ovations. But in this instance was disputable who has awards - an artist or an acoustic systems ;)
Behind next, I could be biased. Because I would like to sell one pair JBL 4345. Two pairs I will retain for my enjoyment :)

[speakerdave]

. . . . If I understand the JBL 4345 were sold without measurement calibration record?

I am not aware of JBL calibrating individual speakers. We have the response graphs of the design (in the links posted above by myself and Bo) because it was provided us by JBL engineering. I have no idea whether this information was provided with the speaker.

David

[JMD]

Hi,
What a finishing for wood is used for JBL 4345? How do I clean and maintain?

[richluvsound]

Hi,
What a finishing for wood is used for JBL 4345? How do I clean and maintain?

JMD,

Wipe the veneer down with white spirit to remove the dirt and open the grain a little . Just enough to dampen the cloth.
Linseed oil mixed with white spirit - about 50% , 50% . I find this brings wood
back to life. Other members have different methods.

Rich

[Krunchy]

Very Nice Bohdan! JBL 4345's & children seem to go pretty well together :). They seem to be in great shape aside from the surrounds.
Post some more pictures when you get a chance, we are all very excited and welcome! ;)

[JMD]

Rich,
thank you, I'll try...

[JMD]

My JBL 4345 of instalation at home. Here is see of childrens protection. This pair JBL 4345 I would like to sell.
Bohdan

[JMD]

These pairs wait for refoam in underground. Here is see shopworn body - finishing. These pairs I will retain for my enjoyment ;)

Bohdan

[Robh3606]

DON'T STORE THE DRIVERS FACE UP!!!!

The spiders will sag and you end up needing recones. Put them back into the cabinets until you can get the foam or store them on edge. Gravity is not your friend.

Rob:)

[JMD]

Hi Rob,
I demounted drivers last weekend, beacause foams are at home ;)

[Hofmannhp]

Hello Bohdan,

you'd done well with the registration of your speakers.
In the meantime I made a small editing of your entries and approved your speakers.....thanks for your contribution.
Now they are saved till infinity.
We will check up the numbers for more information and let you know.

HP

[Mr. Widget]

These pairs wait for refoam in underground. Here is see shopworn body - finishing. These pairs I will retain for my enjoyment.If you need fresh grille fabric contact member Zilch. He bought a surplus of the dark blue JBL grille cloth and can get you enough to do a speaker or ten of them. :D


Widget

[JMD]

Hi Widget,
thank you for contact to Zilch. I'm busy with my family because my childrens very energetic.

[JMD]

Hi HP,
all pairs have originals drivers. Question mark in serial nomber it's mean, I haven't their now. He can't chek it yet, because my friend is very busy.

Thank you.

Bohdan

[Hofmannhp]

Hi HP,
all pairs have originals drivers. Question mark in serial nomber it's mean, I haven't their now. He can't chek it yet, because my friend is very busy.

Thank you.

Bohdan


ok Bohdan,

maybe you can also write down the numbers of the crossovers, horns and lens. Then they are complete.

HP

[JMD]

I sold JBL 4345 to a member of forum LH to Belgium last Friday. I made weaken position of the Slovak Republic :coolness: I think about it, I would like sell another one pair JBL 4345 from pictures down.

[JMD]

Hi
I haven't users manuals for JBL 4345, where was write about amplifier's connection. If connection of battery test and bass speaker go out, so black connector of loudspeaker = positive output of amplifier and red connector of loudspeaker = negative output of amplifier. Is it correct? The circuits from LH is different.

[Robh3606]

Hello JMD


The phasing in the cabinets is the woofer is "JBL" and the rest in normal. So using a 12-18db crossover you would wire the top and bottom out of phase which is red to red and balck to black on the Woofer. That is how the speaker is normally used with either the internal passive or 18db active JBL crossover. Using a 24db that would be in phase. To wire the woofer in phase put the + from the amp on the Negative/Black terminal.


Rob:)

[jpj]

I have a pair of 4345 (big loudspeakers reconed) - outside perfect, no scratch.
who has an idea of the average price?

the 4345 are perfect and i Love them.. but my wife needs some more space in the living rom...

[Ian Mackenzie]

It really depends if the buyer is in Europe or the USA.

In Europe they will (as with any JBL branding) command a much higher price.

[richluvsound]

Hi,

if your serious please post some good photos . PM me !

thanks, Rich

[caladois]

I have a pair of 4345 (big loudspeakers reconed) - outside perfect, no scratch.
who has an idea of the average price?

the 4345 are perfect and i Love them.. but my wife needs some more space in the living rom...


Please, do not hesitate to contact me. I am not that far ...

Regards Stéphane

[jpj]

I hope it worked..(attached file)

[John]

I hope it worked..(attached file)


Me thinks you need a bigger T.V. ;)

[jpj]

Me thinks you need a bigger T.V. ;)



Yes that's probably one solution! The other would be NO TV at all.. because it is my first enemy, and i like to see it when it is OFF...and have the opportunity to put ON the two blue boxes
...

[Rolf]

Yes that's probably one solution! The other would be NO TV at all.. because it is my first enemy, and i like to see it when it is OFF...and have the opportunity to put ON the two blue boxes
...

Agree. When listening to music my TV is (almost) off in these cases. But when watching a concert on DVD (2Ch only) it is nice to see it on a big screen, so maybe the answer is: The best of the two worlds together???

Just my thoughts.

[Guido]

:offtopic:

TV is the most dangerous and serious problem of the 1st world countrys.
Our children already suffer from this crap but we will notice it only in 10 or 20 years.

I almost NEVER watch TV. It's something for bored people :(
I'm never bored. I have too many JBL speakers.

[Hoerninger]

TV. It's something for bored people :(
I'm never bored.

Good point.
_________
Peter

[hjames]

:offtopic:

TV is the most dangerous and serious problem of the 1st world countrys.
Our children already suffer from this crap but we will notice it only in 10 or 20 years.

I almost NEVER watch TV. It's something for bored people :(
I'm never bored. I have too many JBL speakers.

Oh please - its not a problem when kept in moderation,
but excess consumption of TV can cause all the problems seen in modern youth.

(.. ha ha ha, do you realize just how silly that really sounds??)
Actually, the real blame is that Rock and Role has corrupted our youth .. Smash the vinyl!! :applaud:

[Ian Mackenzie]

Here's an idea for some of you to try.

For a while now I hav had my 43545 rasied on stands about 6 inches off the floor so the slots were around ear height. ( I have leather recliner chairs that are higher than a couch)

Today I had some assistance to take them off the stands so I can re paint the baffles JBl Blue.

Anyway I decide to angle the boxes up slighlty with some 2 inch timber under the front and toed them in a bit.

Well the result was brilliant. Its just sounds right.

I think I have hit the sweet spot for the all important vertical dispersion of the horn/ slot. I also suspect that given the area of the baffles, the offset angle vertically and toe in helps break up and scatter front to rear reflections in the room. The bass is sweet by the way!

I might post a pic later in the week.

iMac

[BMWCCA]

The bass is sweat by the way!

I might post a pic later in the week. That would be an interesting picture! I'm still looking for a reason to either buy or not buy the NC 4345 (if the seller ever makes up his mind) but, since I already perspire profusely and my home isn't air-conditioned, your description of the composition of the 4345 bass might just provide a tipping point. My 030's have produced dry, if somewhat limited, bass for half a century. Have you tried an anti-perspirant on your 2254Hs to see if that helps? Maybe some terry-cloth under the cabinets? ;)

[Krunchy]

Today I had some assistance to take them off the stands so I can re paint the baffles JBl Blue.
Anyway I decide to angle the boxes up slighlty with some 2 inch timber under the front and toed them in a bit. iMac

Hello Ian! That is pretty funny, I was laying in bed last night thinking about just such a thing (this is whats on my mind as I am trying to go to sleep, its getting bad folks!). I was trying to figure out how to cut some lumber so that you get a controlled angle as you are ripping it on a table saw, some kind of jig I would imagine (woodworkers please chime in :)). I got on that train of thought as I remembered seeing a set of stands here on the forum for I beieve a set of L100's or 43xx?? dont remember the model exactly but they were slanted/angled. Defintitely post some pictures Ian when you get a chance I would be very interested to see what you came up with.
BTW like the new ayvatar, looks familiar, what is it?


I'm still looking for a reason to either buy or not buy the NC 4345 (if the seller ever makes up his mind)

So whats the deal with the seller at this stage, is he angling for more $ or what? When's the last time you spoke to him, is he jerking everyone here around, he sounded like he wanted to do the deal right awy when I talked to him.
As for buying or not, well the verdict is in on that I beleive. From my own limited experience with them they are simply great! If a little more time had gone by between my recent aquisition I would seriously be thinking....... quadruplets! :D. Some people collect cars I could get into collecting 4345's.
I A/Bd them against the 4430's and they were just so much more alive! Bo's still mesmerized by his and refining their sound, I got plenty of years of blissfull tweaking ahead of me since I'm just beggining the journey. ;)

[Ducatista47]

nce I would be very interested to see what you came up with.
BTW like the new avatar, looks familiar, what is it?


Ian will back me up or shoot me down here, but it sure looks like HAL from 2001: A Space Odyssey. The supercomputer from U of I in Champaign-Urbana with a few important issues (explained in 2010 - conflicting instructions). The film was released about 1968, but oddly enough the campus at Urbana did become a world center for supercomputing development. Want to build your own from old PCs? Google "Beowulf computing." My new favorite word: beowulfery!

I have wondered about angling them up. too. Studio soffit mounting angled them down to face the listener, so why not? Unless of course the move does not successfully uncouple the box from the floor.

Clark

[Robh3606]

BTW like the new ayvatar, looks familiar, what is it?


HAL from 2001

Rob:)

[BMWCCA]

So whats the deal with the seller at this stage, is he angling for more $ or what? When's the last time you spoke to him, is he jerking everyone here around, he sounded like he wanted to do the deal right awy when I talked to him.I have not communicated with him in a few days. He said he was overwhelmed by the response and was going to take the weekend to take some better photos and consider what he was going to do. He did say this seemed to be the only audio product he's ever bought that actually was going to make him money. I believe he's sincere, but he's also trying to maximize his income from these without having to go to the trouble of shipping them. I'm not even sure matching his asking price and picking them up would get them now. A proper purchase works itself out. I'm not going to agonize over it.

[richluvsound]

Hello Ian! That is pretty funny, I was laying in bed last night thinking about just such a thing (this is whats on my mind as I am trying to go to sleep, its getting bad folks!). I was trying to figure out how to cut some lumber so that you get a controlled angle as you are ripping it on a table saw, some kind of jig I would imagine (woodworkers please chime in :)). I got on that train of thought as I remembered seeing a set of stands here on the forum for I beieve a set of L100's or 43xx?? dont remember the model exactly but they were slanted/angled. Defintitely post some pictures Ian when you get a chance I would be very interested to see what you came up with.

krunchy,

like this

[Ian Mackenzie]

That would be an interesting picture! I'm still looking for a reason to either buy or not buy the NC 4345 (if the seller ever makes up his mind) but, since I already perspire profusely and my home isn't air-conditioned, your description of the composition of the 4345 bass might just provide a tipping point. My 030's have produced dry, if somewhat limited, bass for half a century. Have you tried an anti-perspirant on your 2254Hs to see if that helps? Maybe some terry-cloth under the cabinets? ;)

Typo.

The bass is the best part of it imho.

At this point your a tyre kicker

[Ian Mackenzie]

Ian will back me up or shoot me down here, but it sure looks like HAL from 2001: A Space Odyssey. The supercomputer from U of I in Champaign-Urbana with a few important issues (explained in 2010 - conflicting instructions). The film was released about 1968, but oddly enough the campus at Urbana did become a world center for supercomputing development. Want to build your own from old PCs? Google "Beowulf computing."

I have wondered about angling them up. too. Studio soffit mounting angled them down to face the listener, so why not? Unless of course the move does not successfully uncouple the box from the floor.

Clark

Your guessed it. Between that film and this place there are some remarkable similarities.....LOL. Its an avatar also used by Nelson Pass.

[Ian Mackenzie]

Rich's got the idea.

They need to be off the floor and everyones place is different so you will have to play with it.

I had thought of an adjustable stand as well using either a pivot bearing and lock pins for height adjustment but it would have to be welded

[Krunchy]

Good idea Ian and definitely worth looking into. There's plenty of design options here and playing around with them's half the fun, I have pretty deep carpet and was thinking of spiking as well tilting and then tilting :cheers:. thanks a bunch!

Rich! Thanks for the sketch, yes, that would do nicely :)


I believe he's sincere, but he's also trying to maximize his income from these without having to go to the trouble of shipping them. I'm not even sure matching his asking price and picking them up would get them now. A proper purchase works itself out. I'm not going to agonize over it.

I would'nt! I am sure another pair will emerge in due time. He's probably going to try and cash in on these pups. It aint over till its over and these kinds of things can fall apart pretty quickly. He'll easily get his top asking price but I dont think I personally would be going too far beyond that unless they were mint, just MO. Lets see how this plays out, dont throw in the towel just yet.

[Mr. Widget]

Rich's got the idea.

They need to be off the floor and everyones place is different so you will have to play with it.

I had thought of an adjustable stand as well using either a pivot bearing and lock pins for height adjustment but it would have to be weldedADS did just that with their L900 monitors.

Here are some images from CL...


Widget

[BMWCCA]

at this point your a tyre kickerAfter 25 years in the high-line European car business in the states, I know what a tire-kicker is. I'm a potential customer. But, given the somewhat sanctimonious attitude here, I may have to defer to my last-name-sake, Groucho, and say I don't think I want to joint a club that would have me as a member.

We used to enjoy a T-shirt worn by several in the BMW motorcycle clubs: "It's hard to be humble when you ride the best." I have no doubt BMW makes the best motorcycles. I have little doubt the 4345 could be the best JBL system. Back in 1971 they didn't believe me at the BMW bike dealer when I showed up as a high-school senior professing to be interested in buying an "expensive" brand-new BMW motorcycle for $1475. Until I came back with the cash. I never made their mistake in dealing with my customers. Instead I carefully and deliberately answered their questions and objections until they were left with no reason not to do the deal.

The 4345 may just not fit in my "garage" at the moment, but the indecisive nature of the seller makes me less inclined to treat this as a game and, instead, just say "no". The right purchase at the right time will feel . . . right.

[Ian Mackenzie]

The garage. That definately rules you out.

I am told Ken had cognitive dissonance about part out his 4345 in the end:D.

Keep your shirt on we've only having a laugh.

[BMWCCA]

The garage. That definately rules you out.

Keep your shirt on we've only having a laugh.Me, too! :D

(The "garage" reference is a metaphor for my life. Y'all have a pile of speakers. I have twenty German cars and motorcycles . . . and five pairs of JBLs. Everyone has a cross to bear!)

[merlin]

[QUOTE=Krunchy;205919]Hello Ian! That is pretty funny, I was laying in bed last night thinking about just such a thing

Look up the TAOC 300DLC Stand - it's already available in stores across Japan.

[Krunchy]

Hello Merlin! thank you for the info, looks pretty interesting giving you different angles to play with as well. I'm going to go the DIY route on this one, first a little research to see what kind of an angle would offer the best results. Maybe start off with something like a 12-1 pitch and experiment further from there.

Be Well! ;)

Mr. Widget, I like the ads solution, very versatile to be sure, I just wouldnt have the heart to drill into the sides of the cabs.

[Robh3606]

Apparently you guys missed the Slovakian solution

Rob:)

http://www.audioheritage.org/vbulletin/showthread.php?t=10490&page=14

[Krunchy]

Hi Rob,
I remember those, very military but I do like the variable height options. :applaud:

[richluvsound]

krunchy,

tempt that rascal Rob up to yours with his Smaart or something like that !

Good bottle of Single malt should do it . If you get Balavenie 21 , and you leave to top off your to get a visit from Saeman.

Where is that little begger ? This place lacks something special when he ain't posting !

Rich

[Krunchy]

krunchy,

tempt that rascal Rob up to yours with his Smaart or something like that !Rich
Rob and I have been planning a get together but star alignment has not been right, I remain optimistic though! :D


If you get Balavenie 21 , and you leave to top off your to get a visit from Saeman.
Rich

:rotfl: :rotfl: :rotfl:

[richluvsound]

Krunch,

when Bo flew by and we had a look at what the room was doing - then set the PAR up :D Dude, it was like firing them up for the very first time.
You have all this to look forward to ! ........But , I guess it never ends. there is always something to play with , something little tweak these guys come up with. I LOVE IT :applaud:

Rich

[Ian Mackenzie]

Rob,

That idea was what made me think about it,

However I dont think we have the right solution yet.

Those are really industrial and you still have the weight issue trying to adjust them.

I was thinking of a tble adjsutment like a Router table with a thread to get the angle right.

Ian

[Krunchy]

Rich,
I am sure there is plenty of tweaking to be done. There is definitely some funky stuff going on in that room, especially with the sloping ceiling directly above the speakers, there are probably voids and black holes and who knows what else. Plus with all the sound absorbing and reflecting toys and what nots its bound to be interesting to say the least. And thus the journey begins and evolves :)

Ian,
A design that allows for height and angle andjustments would be ideal and probably not that hard to come up with. Just a matter of how involved one wants to get I would imagine, sky's the limit w/this.

[cooky1257]

Or just raise them off the floor and get an adjustable seat:D

[Robh3606]

Or just raise them off the floor and get an adjustable seat:D


That's what I do

Rob:)

[eziodoc]

I can't belive all the interest in this 30 year old system. It was never very successful during its life time primarily due to its size. Most people would get something smaller. It also had a reputation for less than detailed bass, which I have always thought was due to the enclosure not being quite large enough. I haven't thought about these things in years but since I have received a few requests for comments - here goes.

The system was and probably still is a stellar performer if you like the inherent sound of the traditional big JBL 4-ways. There is good news and bad news in the basic design. Good in that they are dynamic as hell and never get confused with intermodulation products of any type. They don't take much power to run and can swallow up a really big amp should you wish to do so. The weak areas of that type of design are several. First, there is a large time off-set between the 10" driver and the HL92 horn. This shows up in both the on-axis response, the directivity pattern and the homogeneity of the driver blending. The second problem is the use of a passive crossover between the top of the woofer and the bottom of the 10". Passive crossovers set to frequencies below about 500 Hz react badly with the motional impedance of the woofer/box combination and give substantial gain around 100 Hz. Gain out of a passive system is generally a bad thing. In the case of the High Pass, we have to work the passive network through a really large motional impedance peak resulting from the 10" fundamental resonance in the sub enclosure. This means that the actual voltage drive that occurs at the terminals of the 10" is less than ideal. There was the added complexity that the Marketing folks of that time required switchable bi-amp capabilities in which the incorrect setting of the switch was not allowed to hurt anything. These little things all add up to additional insertion loss for the woofer and loss of damping control. Now all of this sounds pertty bleak, but as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway.

My sonic memory of the big 4 ways, the last of which was the 4344MkII, is that they are effortless, dynamic, pretty low in coloration and really "alive". They are a little vague by today's standards in terms of precise imaging and although they are very low in intermodulation effects, they are not as detailed as really good lesser way designs. There is no simple answer to any of this and no one design statement that is best. Everything is a series of compromises, and the 4345 has a very good set of complimentary compromises.

I noticed a comment earlier in this string regarding the 2122H. It is a really good voice transducer. It always has been and always will be. Things just sound really natural through it. Another one that might be slightly better is the 2123. It is a little less smooth but perhaps a little more realistic on voice. Either are really good for that critical range from a few hundred Hz to about 1500 Hz.

I imagine you guys have talked about and tried lots of things to get the most out of the system. I will mention a few things that I would do if I had a pair at home for my primary system.


Get rid of the bi-amp switch. Hardwire it in which ever mode you want it. The switch is not that great.
If you can work out bi-amping do so. The difference in the 2245H and 2122H will be amazing. The crossover will have to be non standard. Neither driver is flat around crossover so the voltage drives will need to be adjusted to get proper acoustic bandpasses.
The network components should be updated and this isn't easy. All the capacitors should be polypropylene and you would want to use air core inductors where ever possible. I believe the 4345 used some tapped iron cores. Those are hard to replace with aircores because the surrounding network topology would have to change and all of the values have to be re-engineered. I would suggest leaving them alone unless you are really good at this stuff.
If you can swing it, go to a biased network. The difference is unbelievable.
The ring radiator hates passive networks. A major improvement in the upper range would be to drive the 2405 from its own little amp. You only need 3 or 4 v rms. The 2405 does 110 dB for 2.83v. It is padded way down in the system. There is little real power at those frequencies anyway. You only need to know the voltage output of the amp, power is irrelevant. The 2405 is about 12 ohms and won't draw much current. I would use some little chip amp with a 2ond or 3rd order low level highpass in front of it. Take off the passive network to the ring and just feed it straight. Make sure the amp doesn't make a DC thump on turn on or turn off. That will fatigue the diaphragm. The amp will also have to have really low noise characteristics as any hiss will be really loud directly into the ring. I used to use an old Marantz 1030 integrated amp to run my rings. I could separate out the power amp section and the tweeters always sounded really good.
The L-pads aren't so hot either, particularly after all of these years. Once you have your preferred balance, it is fairly easy to measure each leg of the L-pad and replace it with fixed resistors.
I notice from many of the pictures that the system is elevated on blocks. It is very good to get the 2245 up off of the floor to minimize midbass fatness.For resale reasons, you should be very careful about doing as much of this as possible reversibly.

Before closing I should comment briefly about the 250 - 4345 comparison. Simply put, I prefer a 250. I like the bass quality of the LE14 woofer. Alway have and always will. The 2245 when used as a dedicated sub is one of the best sounding woofers ever. It has an amazing blend of speed, pitch and punch. So does the 14" but the 18" is better. Unfortunately the 18" dislike for passive networks hurts it more than the 14" is hurt by a passive network. I think the mid and high range on the 250 is smoother and much more open however the 4345 wins by a bunch in terms of effortless dynamic sound. I have made all of the above changes to 250 systems (except for separate amp on UHF) and the improvement is huge. I have not done so on the 4345 but I suspect that that system will benefit from theses changes more than a 250 would. If both systems were tweaked out to about the same level, I suspect it would be very hard to come up with a clear overall winner, but I think I might lean towards the 4345 as having the greater potential.

Thank you all for the interest in my work. I must admit I have been blessed with a really nice profession that has treated me well for a very long time. Remember that sound and music enjoyment are very personal things and that what makes you happy may or may not please others. Screw them. If you are happy and no one is geting hurt then go for it. No loudspeaker system even approaches real life so there is plenty of room for interpretation.

Thank you, Tim.
Wonderful lesson.

Ezio
ITALY

[jamdel]

Hi, I am new here. Just scroll through and found this thread. Just want to contribute.

I live in Singapore. I do own a pair of this beautiful speakers. Had them for about 20 years. The best sounding speakers I have ever heard in my life. Just some pictures of it.

Cheers...

http://i18.photobucket.com/albums/b142/jamdel007/JBL%204345/P1010186x.jpg

http://i18.photobucket.com/albums/b142/jamdel007/JBL%204345/P1010188x.jpg

http://i18.photobucket.com/albums/b142/jamdel007/JBL%204345/P1010190x.jpg

http://i18.photobucket.com/albums/b142/jamdel007/JBL%204345/P1010189x.jpg

Have also incluse a picture of how I put them. I used rollers. Easier to mop the floor.... :)

[caoutchouc]

I have a pair of 4345 (big loudspeakers reconed) - outside perfect, no scratch.
who has an idea of the average price?

the 4345 are perfect and i Love them.. but my wife needs some more space in the living rom...

Bonjour. Je tombe par hasard sur votre annonce, êtes vous toujours décidé à vous séparer de vos enceintes ? J'ai une paire de 4343 et j'aimerais tenter l'aventure des 4345. Cordialement. Caoutchouc

[Rolf]

Bonjour. Je tombe par hasard sur votre annonce, êtes vous toujours décidé à vous séparer de vos enceintes ? J'ai une paire de 4343 et j'aimerais tenter l'aventure des 4345. Cordialement. Caoutchouc

That was understandable!

[midlife]

Very nice arrangement, but surely the items on your speaker tops rattle, no?

[Ian Mackenzie]

That was understandable!


Yes it was:


Hello. I fall by chance on your advertisement, are you always decided to separate you from your enclosures? J' have a pair of 4343 and j' would like to try l' venture of the 4345. Cordially.


Pity the mid cone surrounds are on the front side of the cones.




Oui il était : Citation : Bonjour. Je tombez-vous par hasard sur votre publicité, êtes-vous toujours décidé de vous séparer de vos clôtures ? J' ; ayez une paire de 4343 et de j' ; voudrait essayer l' ; entreprise des 4345. Cordialement. Plaignez les mi bordures de cône se trouvent sur la face frontale des cônes


Veuillez excuser Rolf' ; s. Son écorce est plus mauvaise puis sa morsure