4345 Project

[JBLCanuck]

4345's are coming along extra nicely.
Baffles are finished including the ports, all the mill work is done...now if my shop would just warm up I could glue them together!
I have 3-1500 Watt heaters going & it barely takes the chill off.
My shop is 10,000 square feet with vintage windows all the way around & no insulation in the ceiling. :crying:
We just got hit with some real cold weather & snow so it's slowed me down.
Oh well....might have to move them into the kitchen so I can finish them
up. :D
The cabinets are actually not difficult if anyone's planning on building a set.

[Chas]

Hey, how about some pictures, please?

[bigyank]

Hey, how about some pictures, please?

He said...............Pics please!:applaud:

Yank

[JBLCanuck]

Not much to take pictures of yet.
I made a third baffle for when I want to make more 4345's, I have a
template :). Much easier to cut the baffles with a saw & then trim them perfect using a template & router than using circle cutters.
Hopefully if I get a chance I'll glue the boxes together this Weekend.
Here's a couple of pictures from when I cut the baffles...http://members.shaw.ca/missionkraft/baffle6.jpg

[JBLCanuck]

Pretty straight forward easy stuff.
http://members.shaw.ca/missionkraft/baffle7.jpg

[Chas]

Easy? Yeah, maybe for you! :) Nice idea using a template and a router. Looking good, keep us posted, please.

[maxwedge]

Easy? Yeah, maybe for you! :) Nice idea using a template and a router. Looking good, keep us posted, please.
I was thinking JBLCanuck was using a Jasper Jig but its something similar.
http://www.partsexpress.com/Tech/365-250.html

[JBLCanuck]

Yes, it's similar. I actually have two of them...the one in that picture only works up to about 7" diameter & is very accurate. The other one goes from 5" to something like 40" & works great but not quite as acurate as the smaller one.
So all the snow here slowed me down over Christmas but I got a couple of hours to get back at them today. So I have them sitting in my shop with a couple of clamps just dry fit & everything fits perfect. I actually knew they'd fit...I just wanted to see them sitting looking like 4345's.:D
So all that's left before gluing is to add the internal bracing, & glue the doghouse to the front baffle & they's ready to glue :)
Then all the easy part is done & time for the part I'm not looking forward to....veneering :help:
So hopefully soon they'll take shape :applaud:

[macaroonie]

Its all in this thread. Shameless plug. http://audioheritage.org/vbulletin/showthread.php?t=17238&highlight=backyard+box+building Its not as difficult as you might think and I did it the hard way.
Start from post 81

[JBLCanuck]

Thanks Mac, I've read through your post...beautiful job you've done!
I'm leaning towards the Titebond glue route. Your job looks fantastic & I'm sure you know something I don't because as Saeman has experienced....me too whenever I've veneered using Contact Cement. I've tried water based, oil based, rolling, spraying....waiting longer before bonding......never been happy with my end result over time.
My latest screw up was I used white glue on venner without the paper backer. I decided I'd use a piece of 1" plywood I had & clamp the veneer down...evectively like a big press since it was only a 1'x1' area.
When I removed the clamp the next day....:crying::crying:..the venner was like a washboard! I guess the moisture on one side of the venner isn't good?:D
Anyway....it'll be veneering trials #156 for me here but after reading all the threads on Titebond II & ironing it on....it sounds like the answer I've been looking for. I find with my contact cement jobs...enevitably it's come loose at the edges. I just can't imagine white glue letting go once it's cured.
How have you found yours have held up?

[macaroonie]

The point you may have missed is that I primed the surfaces or in other words two coats of adhesive. I was also using a commercial grade which may have better performance. I tried an adhesive film but it was crap but my smelling salts supplier recently had some film which behaved in a totally different way to the stuff I had. She has been using it for years for veneer repairs. In this case she repaired the top of an upright piano completely with a fiddleback veneer removed from somewhere else. Don't ask me how she did that !!. The end result was outstanding , using her self adhesive film.
I would suggest getting samples and try some out.
Good luck

[JBLCanuck]

Well, with Christmas & all the kooky weather we got here out West it's delayed my progress but I put a few hours in this Weekend & got my DIY 4345's all glued together & ready for veneer. I glued the Walnut profile on the front this evening, since this picture was taken & so far everything has gone real smooth. I took in my 4301B's & had the blue paint matched up & so a little veneer, a little painting & they'll be looking pretty smart :)
Then the grills....fiddly ugly job that'll be.
Thanks for all the help!:applaud:
http://members.shaw.ca/missionkraft/cabinets3.jpg

[SMKSoundPro]

WOW!

Looks Great!

Don't Stop!

Please keep us informed of your progress!!!

I love building and retrofitting speaker boxes.

scotty.

[bigyank]

Very nice. How about some closeups of the bracing! :D

Yank

[JBLCanuck]

The only alteration from factory 4345's I decided to make is that I don't like the way they just glue the 1/2" thick profile on the front edge & then paint the remaining PB that extends beyond the baffle, blue.
I cut my profile & then left 1/16" that extends the extra 1/2" so that it extends right to the baffle....basically making the top & side 1" PB appear to be 1-1/16" thick...which is how thick the original JBL material was anyway...you follow?
I'll post a pic later.
Got my Iron...my Titebond II...my veneer roller...all ready to roll :D

[JBLCanuck]

Can anyone tell me how far apart the pairs of speaker clamps are on the 2245H's? The drawings on the forum here don't give a measurement. It looks to be about 2" or so but I haven't drilled any holes in my baffles hoping someone had a pair they could measure for me.
Thanks :)

[BMWCCA]

Can anyone tell me how far apart the pairs of speaker clamps are on the 2245H's? The drawings on the forum here don't give a measurement. It looks to be about 2" or so but I haven't drilled any holes in my baffles hoping someone had a pair they could measure for me. Well, if Riessen-reproduction measurements will help, mine are spaced exactly 2" apart measured linearly (not on the curve of the circumference). Also, FWIW, my black-ash versions have no exposed particle board between the baffle board and the solid-wood cap. I'm guessing the "cap" is larger enough to extend to the baffle, but I'm sure Rick can tell you what he did. I'll re-post one of his photos below so you can see if we're talking about the same thing.

I hope that helps.

http://audioheritage.org/vbulletin/attachment.php?attachmentid=24870&stc=1&d=1178425923
(http://audioheritage.org/vbulletin/attachment.php?attachmentid=24870&stc=1&d=1178425923)

[JBLCanuck]

Awesome...Exactly what I needed to know. If Ricks are 2" apart...I'm betting so were factory JBL's :)
Yes, on yours, Rick has either done them the same as I have or else he's done them the same as JBL does but veneered that 1/2" reveal because since he left that baffled stained...you wouldn't want PB showing.
Thanks very much for taking the time to measure for me! :)
Great buy on those, by the way! :D

[Chas]

Pleased to confirm: 2" center to center for factory cabinets over here. More pics after veneering, please!:)

[BMWCCA]

Great buy on those, by the way! I obviously don't have your talent to do it for myself! And space is so tight here, they're still in the van. One big-box pair has to leave to make room for another. :banghead:

You're doing a great job on yours. Thanks for sharing the process. :applaud:

[John]

The only alteration from factory 4345's I decided to make is that I don't like the way they just glue the 1/2" thick profile on the front edge & then paint the remaining PB that extends beyond the baffle, blue.
I cut my profile & then left 1/16" that extends the extra 1/2" so that it extends right to the baffle....basically making the top & side 1" PB appear to be 1-1/16" thick...which is how thick the original JBL material was anyway...you follow?
I'll post a pic later.
Got my Iron...my Titebond II...my veneer roller...all ready to roll :D


All panels are 1" on factory 4345 cabinets.:blah:

[BMWCCA]

All panels are 1" on factory 4345 cabinets.:blah:I'm not questioning what you say, just offering this data point (misc. note, below) since it was so fresh in my mind from my study of the projects:
http://audioheritage.org/vbulletin/showpost.php?p=122406&postcount=16

http://audioheritage.org/vbulletin/attachment.php?attachmentid=17909&stc=1&d=1156917936

[BMWCCA]

The only alteration from factory 4345's I decided to make is that I don't like the way they just glue the 1/2" thick profile on the front edge & then paint the remaining PB that extends beyond the baffle, blue. Ahh! I see what you mean, as shown in Bo's picture here:
http://audioheritage.org/vbulletin/attachment.php?attachmentid=308&stc=1&d=1058154939

[John]

I'm not questioning what you say, just offering this data point (misc. note, below) since it was so fresh in my mind from my study of the projects:
http://audioheritage.org/vbulletin/showpost.php?p=122406&postcount=16

http://audioheritage.org/vbulletin/attachment.php?attachmentid=17909&stc=1&d=1156917936

Perhaps I am wrong, but I know on my 4331, 4333 cabinets they are 1" PB with 3/4" 13 ply baffle and assumed that the rest of the 43xx line that used PB for cabinets were the same.:o:

In respect to the walnut front edge on the 4331.4333. The PB cabinet panel does extend past the front baffle but JBL fit the walnet front edge in such a way as to be invisible.:blah:

[saeman]

Perhaps I am wrong, but I know on my 4331, 4333 cabinets they are 1" PB with 3/4" 13 ply baffle and assumed that the rest of the 43xx line that used PB for cabinets were the same.:o:

In respect to the walnut front edge on the 4331.4333. The PB cabinet panel does extend past the front baffle but JBL fit the walnet front edge in such a way as to be invisible.:blah:

Most all 43XX monitors have 3/4" baltic birch baffles. Exceptions are 4315 with 3/4" P.B. and 4340,4341 and 4343 which use 1" P.B. for their baffles.

Most of the big monitors have the baffle recessed in from the front trim edge 3/4" to 7/8" depending on the model. The 4350 wall are 3/4" B.B and the face trim is 3/8" thick glued to the face of the cabinet. Generally the overhand is 3/4" so that leaves 3/8" of cabinet wall overhanging the baffle before installation of the trim.

On the other bevel face models the walls are 1" thick and the trim is generally 1/2" thick, again on top of approx. a 3/8" overhang.

For the most part JBL simply glued this trim in place. This might sound like poor practice buy if the cabinet is sound and has not been exposed to an overly dry or moist environment you'll play hell getting the old trim off without damage to the cabinet. I used to pry it off using a chiesel but left too many bomb craters in the P.B. sides. Now I edge guide router it off for my restorations.

This is when I found that they sometimes nailed the trim in place. I've trashed several good router bits in the process. I suspect that they did this when necessary to hold a warped piece in place. The nails were then set and finished over. Beware!!

[JBLCanuck]

Hi Rick,
In the diagram in "System Information" it says JBL used 1-1/6" PB on the 4345's....or was that including veneer or something?
Doesn't really matter because I don't think anyone sells such a product anyway.
Thanks for all the help & advice on these....it would be impossible without the expertise of others who've had the opportunity to get an original set apart & spend hours drawing pictures for the benefit of us rookies :)

[BMWCCA]

On a related topic, has anyone come up with a part number, repro, or drawing for the bracket that supports the 2425J by attachment to the mid-bass box? I saw it once in a photo but can't find it now and my reproductions seem to be lacking that piece. I'm sure I can create something that would accomplish the purpose, but it'd be nice to have something close to original, if possible. I'm assuming it's important to have in place, yes? :dont-know

[JBLCanuck]

So, Is that the same bracket as used with the 2421's/2307 on the 4345's?
I'm making 2 of them shortly for my pair...there are drawings of it in the Systems Info section...pretty simple little sheet metal bracket if we're talking about the same one?
I could probably make an extra pair if this is the bracket you're talking about. http://members.shaw.ca/missionkraft/bracket.jpg

[Chas]

That's the one. :)

[BMWCCA]

I'm making 2 of them shortly for my pair...there are drawings of it in the Systems Info section...pretty simple little sheet metal bracket if we're talking about the same one?
I could probably make an extra pair if this is the bracket you're talking about.That is the one. I suppose driver make no difference since it's the horn-flange mounting bolts it attaches to so spacing would be the same. Let me know when you get to that point. It seems to serve a purpose. ;) Do you have the horns you're using? Mine are supposed to be 2306.

Thanks for the drawing link. I knew I'd seen it somewhere. It does look like something even I could fabricate with some snips, a vice, and a file. Yours would likely look less rough! :o:

Thanks.

[JBLCanuck]

I'm pretty sure the 2306 is just an aluminum version of the 2307...no?
Anyway, if you haven't made them...I'll make you a pair.
Basically, in my opinion, the brackets are not needed.
Usually horns are braced like this for shipping reasons. Once the speakers are sitting in your livingroom...that horn/baffle is plenty strong to support the big heavy magnet but I think JBL braced them because in shipping these big beasts...there's a lot of leverage hanging out there to damage the plywood baffle.
That's my non-expert Canuck opinion :D
That said...they certainly don't hurt.

[BMWCCA]

I'm pretty sure the 2306 is just an aluminum version of the 2307...no?
Anyway, if you haven't made them...I'll make you a pair.
Basically, in my opinion, the brackets are not needed. Yes, simply un-painted, I'm told. And you're probably right about their necessity. But if you do them, I'd be happy to get a pair from you. If we didn't dislodge them in our long hand-truck climb down NewZenith's tall and winding stairway, they're probably substantial enough as-is!

That said...they certainly don't hurt.That's what I figure.

Thanks!

[Chas]

I had a pair of 4325's with the 2307/2420 that was unsupported and never had any problems. Like you say, there must have been a high incidence of shipping damage that spurred JBL to start installing supports.

I can confirm, the brackets are unpainted in my 4345's.

[John]

I'm pretty sure the 2306 is just an aluminum version of the 2307...no?
Anyway, if you haven't made them...I'll make you a pair.
Basically, in my opinion, the brackets are not needed.
Usually horns are braced like this for shipping reasons. Once the speakers are sitting in your livingroom...that horn/baffle is plenty strong to support the big heavy magnet but I think JBL braced them because in shipping these big beasts...there's a lot of leverage hanging out there to damage the plywood baffle.
That's my non-expert Canuck opinion :D
That said...they certainly don't hurt.

I see no problem with 3/4" 13 ply Baltic Birch supporting the load of a small 2425+2307 horn.:blah:

[JBLCanuck]

Today might just be veneer day...wish me luck! :D
I still need one more coat of blue & spray the bottom & backs but I think I'll do that after I finish the veneer process.
http://members.shaw.ca/missionkraft/4345blue.jpg

[SMKSoundPro]

Looks Great! Don't stop!

[JBLCanuck]

One side on each cabinet finished veneering...worked fantastic!
Boy...I wish I learned the white/yellow glue method of veneering years ago!
It's no harder than Contact Cement...in fact it's easier because you can move the veneer around until it's exactly where you want it & then start ironing.
Thanks to everyone who's helped with this project because I really am a veneer virgin :)
The only thing I'd do different next time is I'd get a 10' sheet of veneer so I could do up one side, across the top & down the other side with one 19" strip so that the grain is matched perfectly. The supplier I used here only had 4'x8' sheets & so I needed 2. 1-10'er would have been better.
Next set! :D

[Mr. Widget]

Looking very nice!

I don't think it is just beginner's luck.;)


Widget

[Loud & Clear]

:applaud: Sweet!!! :applaud:

[dino]

looks really great:applaud::applaud::applaud:

[JBLCanuck]

Thanks guys! :)
All veneering finished...honestly...that's the best information I've found so far on this forum.
I've always found veneering intimidating. I've bought veneer that's not paper backed & fought with it...used contact cement where over time the edges have lifted & the edges...always glue showing at the seam.
The Tite Bond glue works perfectly. The only thing that kind of sucks is you can really only do one side of each speaker per day. I found that if you're careful...you can trim the veneer the same day but experts recommend leaving it at least a few hours & preferably overnight before trimming or sanding edges. I guess on smaller speakers you could do 2 sides per day but the 4345's are so big & awkward it would be very tricky to turn them over by yourself without damaging the overhanging veneer.
So anyway...bottom line here...even a beginner can easily veneer his own cabinets with very few tools & no experience. Just follow the methods layed out here by Saeman & other guys with lots of experience....it's really very simple.
I followed Saeman's very helpful tips here....& definitely follow his advice & read the recommendations on Oakwood's Webpage.
Great link here with very, very helpful info....
http://www.audioheritage.org/vbulletin/showthread.php?t=21498&highlight=tite+bond+veneer
Thanks again everyone....I'll be staining today, all being well :applaud:

[Robh3606]

Great give us some more pictures!

Rob:applaud:

[JBLRaiser]

lots of pictures. Too many of gaps so far. Would like to see EVERY step.:bouncy:

[boputnam]

Today might just be veneer day...wish me luck! :D Uh-oh...

A few more weeks of this and we'll being going through all that electrical polarity / acoustic phasing stuff with you, too!! :rotfl:

[BMWCCA]

A few more weeks of this and we'll being going through all that electrical polarity / acoustic phasing stuff with you, too!! :rotfl:Probably with the same cast of miscreants, too! :yes:

[JBLCanuck]

Uh-oh...

A few more weeks of this and we'll being going through all that electrical polarity / acoustic phasing stuff with you, too!! :rotfl:

You got that right Bo! :D
Ian MacKenzie's building my crossovers & I was explaining to him today that I hoped he was capable of explaining to a 7 year old, how to hook them up & get them setup properly...because that's what he's dealing with here when it comes to electronics :D
When I see you guys posting graphs & schematics...I may as well be looking at a novel written in Russian! :o:

[JBLCanuck]

Almost finished the cabinets...I primed the backs & bottoms today...couple coats of satin black & some insulation inside & they'll be ready to start installing drivers & networks :applaud:http://members.shaw.ca/missionkraft/4345-103.jpg

[hjames]

Almost finished the cabinets...I primed the backs & bottoms today...couple coats of satin black & some insulation inside & they'll be ready to start installing drivers & networks :applaud:

Whoa - VERY nice lookin' boxes!
You should be real proud of this project ...

You guys are gonna make me sell off my puny 4341s
and get something of substance, aren't you ...

The only saving grace is that I haven't actually heard a 4345 yet
(Phil isn't granting an audience with his yet) ...

[Chas]

Looking good, keep the pics comng.:)

[JBLCanuck]

Looking good, keep the pics comng.:)

Here's one more for you :)
http://members.shaw.ca/missionkraft/4345-108.jpg

[Mr. Widget]

Cool... but let's talk about that rocking horse. :bouncy:


Widget

[spkrman57]

I'm all thumbs when it comes to woodworking.:(

Regards, Ron

[JBLCanuck]

Cool... but let's talk about that rocking horse. :bouncy:


Widget

It's all yours if you wanna come get her! :)
I used to ride on that thing 40 years ago. I can remember my feet slipping off the pegs...it was a painful experience that I can remember well :D

[Goodwill_HiFi]

It's all yours if you wanna come get her! :)
I used to ride on that thing 40 years ago. I can remember my feet slipping off the pegs...it was a painful experience that I can remember well :D

Gorgeous cabinets! I'm more of an Altec guy, but have recently become intrigued with JBL. I've never gotten the colors JBL put on their speakers.... white cones, orange grills, etc....... looks weird and/or gaudy to me. This blue looks great with the nice wood, Though. I really like it.

I like the rocking horse too. I have the plastic version from the 70's that my sister and I had. I'm hanging on to it for my own kids..... when I have some. I've been concerned about the plastic breaking. I never thought about making one of wood, until I saw yours. Granted it won't be the one my sister and I rode anymore, although, the frame would still be the same..... at least it'll me a bit more than a modern store bought cheapy.

Oh..... I like the shop floor, too!

[richluvsound]

Canuck,


beautiful work ......... Beaver of Beauty .

Rich

[maxwedge]

Nice!:applaud:

[Ian Mackenzie]

Do you want to post details as in pics, wiring diagrams of the crossover "here" or leave it to later?

[John]

Looking sweet but are you sure you got all the bracing in those cabinets? The bottom looks to have none but I think the factory had 2 on the bottom panel running front to back?:blah:

[BMWCCA]

Looking sweet but are you sure you got all the bracing in those cabinets? The bottom looks to have none but I think the factory had 2 on the bottom panel running front to back?:blah:I'm sure Mr. Canuck has read in the 4345 plans page for the base where it says: "Base provides bracing for the cabinet bottom so cannot be ommitted." (That's not my spelling!)

Canuck: I continue to be impressed by what a superb job you're doing on the cabinets! :applaud:

[subwoof]

I just got this picture from my sister-in-law...

This rocking horse is now sitting in my shop on top of 4 4341's that are awaiting restoration...

It's my wife circa 1961..sniff...

sub

[Allanvh5150]

Good memories will always be with you Sub!:)

[JBLCanuck]

Looking sweet but are you sure you got all the bracing in those cabinets? The bottom looks to have none but I think the factory had 2 on the bottom panel running front to back?:blah:

Hi John,
The only bracing in the bottom of a 4345 is the base.
They're on there...you just can't really see them in those pics.
How's everything in Winnipeg? Are the mosquito's starting to come out yet? :D

[John]

Hi John,
The only bracing in the bottom of a 4345 is the base.
They're on there...you just can't really see them in those pics.
How's everything in Winnipeg? Are the mosquito's starting to come out
yet? :D

Yes my mistake. I looked at the plans again and the bottom is bare.
Does not mean you cant throw a few braces in there anyway. I guess it depends on what your end game is with these? :)

Also about Winnipeg, we had a big meltdown a few weeks ago that took away about 50% of our ground cover and I figure in a few weeks from now the rest will be gone as well. Might be a bit of flooding this spring as there is a lot of snow in North Dakota that will be heading this way when it melts. Could be a huge crop of Mosquito's after that. Time will tell? If it gets bad I will spend more time in my man cave with the JBL's:D:applaud:

If I make it out to the lower mainland this summer I hope those 4345's will be up and running, would love to hear them.:bouncy:

[JBLCanuck]

I built the grill frames last night & so now just install my Zilch cloth & insulation & their done! :applaud:
....or is this just the beginning :Dhttp://members.shaw.ca/missionkraft/4345bases.jpg

[macaroonie]

Very tasty work there. I like the figured profile at the front edge , just adds that little extra. Nice ! :)

[BMWCCA]

....or is this just the beginning :D

I get it! ;)

Again, beautiful work. I can't tell you how impressive it's been to watch your progress. :applaud:

[JBLCanuck]

I get it! ;)

Again, beautiful work. I can't tell you how impressive it's been to watch your progress. :applaud:

Thanks! :)
Nothing about this project was hard. If a guy has a table saw & a router...he's got enough tools to build any cabinets with very little experience needed. There's enough help & expertise on this site that it's just not difficult if you're not in a hurry.
Now I gotta make us a couple of brackets :)

[cosmos]

Man, those cabinets look pretty!

Nice job!

[John]

Yes, Those are looking very nice indeed. Carry on my comrade:applaud:

[Ian Mackenzie]

They look great even upside down!

[Ian Mackenzie]

JBLCanuck,

Do you think we should tell them what we are going to do?:D

Just plan the escape route first...LOL:uhmmmm:

A trick question. What was the final iteration of the JBL 43XX 4 way series and how was it different from from the earlier versions?:bouncy:

[Fangio]

What was the final iteration of the JBL 43XX 4 way series and how was it different from from the earlier versions?:bouncy:
Probably this?

[4313B]

A trick question. What was the final iteration of the JBL 43XX 4 way series and how was it different from from the earlier versions?:bouncy:The final iteration is the 4348 and it doesn't sound as nice as previous versions. It does lack the foam rot though. :rotfl:

The network to use is the 4344 MK II, tweaked accordingly for use with the 2121, 2122, 2123, or 2202 as well as the 8 ohm and 16 ohm 1-inch and 2-inch compression drivers. It is more expensive than the 4344/4345 network. I don't bother with the non bi-amped version. All my networks are bi-amp only as per the 4350/4355. That way anyone can use them with any LF transducer(s) they desire. I personally prefer the LE14H-3, 1500FE or 1500AL. The dual 2234H, dual 2235H or 2245H systems are just too damn big, albiet outstanding.

Even if you happen to have the stock 2123H, 2425H (275Nd) complement you will still want to tweak the bi-amp only version because you don't want to waste energy in the 2123H fixed pad nor would you want to have the L-Pad in the circuit. The fixed pads on the 2425H and 2405H are reduced accordingly. All of this can be nailed down tight with CLIO and LEAP.



Someone recently bought all the D8R275 diaphragms JBL had left in stock so someone is definitely reading this stuff...

[Ian Mackenzie]

Fiangio is correct.

The 4344mk11 used CC (the 4348 was a departure in my mind as it used another horn).

The 4344mk11 used the 2123, a revised woofer,a dusted diaphragm and charge coupling

I will find a suitable price for you.

Ian

[Ian Mackenzie]

Thanks 4313B. Damn. it..LOL

To cut along story short both JBLCanuck and I have the 2123 as a result of some collaboration. On the basis of the 2123H driver availability it was determined that it was worth using it in place of the 2122H.

I never auditioned the 4348 in Japan but Lord Von Zilchmeister has some of the 4348 horns and they were good (as I recall) but I have heard the 4344mk11 and it was impressive. I think Steve K likes them as well.

What it interesting is how JBL have introduced the 2123H and the way it is blended to the horn. When modelled it becomes intuitive that much of the 2123H extended response is used to advantage so that the horn is introduced more gradually and as they say everything is done for a reason. (If you change anything it all goes hello). Not to go into much detail at this stage but we know the 2123H has a non flat response. I don't have SE in front of me right now but way the 4344mk11 filter works is elegantly normalise the response and provide the correct rolloff to the horn without heavy handed L + C values to force the issue.

So to begin with we are not going to reinvent the wheel but your suggestions are appreciated.

There certainly is a lot of copper in this network.

Given the extra bits and with the Dcr values used I expect someone spent a lot of time voicing it on that basis.

If over time there are deemed tweaks (following lengthy auditions) then updates can be arranged.

[4313B]

So to begin with we are not going to reinvent the wheel but your suggestions are appreciated.

If over time there are deemed tweaks (following lengthy auditions) then updates can be arranged.
He sent me a PM last week asking me what to do, I answered, and now it looks like he is doing it. I'd leave out the fixed pad and L-Pad on the 2123H and decrease the HF and UHF fixed pads unless there is some reason to go full passive.

[Ian Mackenzie]

Cool.:cool:.

I will see what it looks like when I get all the parts.

Bought a new inductance meter recently. 2% accurate with a 2 mH (full scale.)

Somehow I prefer the Rolf Harris approach to all this ...just keep throwing paint at the wall. It's all in the eye of the beholder.

Heck we have'nt even got to the freakin wire yet!

http://www.mogamicable.com/Bulk/micr_cables/speaker_cab/speaker1.html

http://attachments.brisound.com.au/products/files/4S6BKM[14].pdf?r=1223869339


Ian

[Fangio]

Fiangio is correct. I will find a suitable price for you

Thanks Ian. Looking forward to it.. may I suggest next time we meet the first drink goes on you, wherever that is ;)


JBLCanuck, stunning cabinets. :yes: Very promising.

In London I've seen how much satisfaction and fun to build these can be. Your woodworking skills are likewise remarkable, and enviable with good reason. Please keep the pics coming.

[4313B]

Thanks Ian. Looking forward to it ;)I thought you had a fully functional pair of nice loudspeakers Fangio? :blink: Are you moving up to 4345's as well?

[Fangio]

I thought you had a fully functional pair of nice loudspeakers Fangio? :blink: Are you moving up to 4345's as well?
Actually I have two pairs, see my avatar.. the all alnico couple I'm enjoying in the living room, the other, upgraded pair is still waiting for reassembling.

I'd rather avoid to hijack this thread with all my intentions. ;) That's partially still up in the air. PM sent.

[4313B]

So to begin with we are not going to reinvent the wheel but your suggestions are appreciated.Yep, nevermind.

[Ian Mackenzie]

I will try and post some images of the crossovers early next week although no response data will be available until all the drivers are available for measurement and analysis.

[Ian Mackenzie]

Okay,

While we are waiting delivery of diaphragms I trialed the networks last night using an alternate Neo 1 inch compression driver as a sort of proof of concept using the 2123H.

The results are very encouraging.

Out of the box as it were without any measurements or adjustments all the hallmarks of the 4345 were there.

Subjectively the 2123H (set-up properly) is very close to the 2122H if not a bit cleaner and more detailed.

[Chas]

.

Subjectively the 2123H (set-up properly) is very close to the 2122H if not a bit cleaner and more detailed.

Ian, that echoes my experience comparing the two as well. I find the 2123H to have the advantage of "higher res", while the 2122H offers a greater degree of smoothness.

Have you tried the 2123H with female vocals?:)

[4313B]

The 2123H, 2425H, 2405H combination sounds really good with the Mk II network but it's too bad that the 2123H requires the filter that it does to work right. It definitely works well as a passive four way.

Have you tried the 2123H with female vocals?:)What loudspeakers do you have again Chas?

[Chas]

Mainly the 4345's. But, I have my (Rube Goldberg) modular set up as well:
2405H Xover :4344/5 equivalent network - first edition
24526/2307 Xover: Ditto
2123H Xover: 4344 MKII cc'd with solens
Pair of 2235A's at 290 Hz


Coming soon:

2452H/PT and Waveguide - Xover: TBA (Zilch has me all confused:D - I will be needing some help on this one!)
2123H Xover Likely the cc'd 4344 MKII again.

[4313B]

While we are waiting delivery of diaphragmsI'm working on it. I have the boxes opened up but have to run to an Easter function right now. I'll start aquaplasing them when I get back.

This weekend wasn't too bad for getting things done. Five 2122H recones, two LE111H recones, two 2204H recones and a 2235H recone. No networks though. :banghead:

[4313B]

Mainly the 4345's. But, I have my (Rube Goldberg) modular set up as well:
2405H Xover :4344/5 equivalent network - first edition
24526/2307 Xover: Ditto
2123H Xover: 4344 MKII cc'd with solens
Pair of 2235A's at 290 HzI thought you had two systems.

[Ian Mackenzie]

Easter Monday here.

4313B,

Dont stress...I know what its like....

I will send you an Egg.....:)

Below is an image of the crossover and the 2123H.

There is a lot of (shit load) work in these things..finding and ordering the parts, figuring out how to put it together (remote project) and assembly.

Weird problems like finding 14-16 awg color coded wire in less than 100 yard reels..no one stocks it anymore. So the wiring is jumbo 13 awg all the way. Good for ground continuity. Getting the chokes wound to spec was the easy part.

If it looks messy it because it is. Point to point is never as tidy as a PCB after about a dozen sticks of hot melt glue.

The project evolved from an equivalent 3145 to a 4344mk11 charge-coupled network mid stream.

I think the results are worthwhile. The whole thing is so ultra clean (on the Pass Labs X 250.5) its spooky.

Basically there is an input-output terminal block, an input ground and signal bus and the mid, horn and 2405 filters and the 9+ volt supply for the charge-coupling. I've had the batteries connected for a week or so. The resisters are metal oxide 10 watt. Capacitors Solen Fast Caps.

The seperate board is the LR network for the 2123H and the horn compression driver (after the L pads). Wiring up the L pads is a pain.

All up there is a lot of copper in these networks.

The 2123H (new old stock) is a real work of art and it sounds better than it looks.

What happens on paper is borne out with this set-up. The mid cone / horn is better integrated and the 2405 less prominant, acting more like a super tweeter.

While the current crop of JBL SOA systems have the benefits of current day technology I suspect the 4 way junkies will not go quietly with a system like this.

[4313B]

Nice Ian!
The 2123H (new old stock) is a real work of art and it sounds better than it looks.I think I like the longer VC of the 2123H and I like the lack of a foam surround from a maintenance perspective.
the 2405 less prominant, acting more like a super tweeter.Note the 2405 voltage drive in the L300/4333, 4340/4341/4343 and 4344 Mk II versus the voltage drive in the 4344/4345 and 4355.
While the current crop of JBL SOA systems have the benefits of current day technology I suspect the 4 way junkies will not go quietly with a system like this.No, I don't either and they are much easier to get as well.

[Ian Mackenzie]

Well I guess this is what makes the vintage stuff so much fun.

Yes the non foam surround is a plus! Either way they are both very fine drivers. (I can see myself getting a pair of 1500FE's sooner or later so I can fit a 4 way in my listening room with the rest of the mess!)

I was wondering about the voltage drive on the 2405 but it seems to work.

This afternoon I messed with a stock DBX analogue crossover adjusted to 340 hz (LR 24 db filters) and it was a breeze to set-up so I expect the Ashly should work fine.

[Ian Mackenzie]

Ian, that echoes my experience comparing the two as well. I find the 2123H to have the advantage of "higher res", while the 2122H offers a greater degree of smoothness.

Have you tried the 2123H with female vocals?:)

Casandra Wilson Blue Light...is my test Cd. Blown away.:bouncy:

While not wanting to topicalise the 2122H/2123H there are differences and there is a method in the madness to getting the best out of both drivers.

The 2122H from my recollection is a bit more lossy (as in self damping make) and obviously it does not have the bandwith of the 2123H. The trade off in smoothness comes at a price in cutting over to the horn and matching in terms of timbre. In that respect acquaplas on the diaphragm is a no brainer once you have heard the difference.

There is a certain magic to the way 2122H works in the 4345.

The 2123H on the other hand needs more passive Eq to smooth the response but its lighter cone and dust cap/surround profile breath life & resolving power above 1 khertz. This puts a different spin on the demands of the compression driver and horn down low.

When I heard the 4344mk11 in Tokyo I knew I was being spoilt.

As Chas hints if you play a lot of female vocal or jazz you are in for a treat. There is no mistaking why the Japanese hold these systems in such high esteem.

For years (back in the 80s) the 2123H was industry standard as the midrange driver of choice in large high powered studio monitors.

If you are wondering why? I just could not resist the challenge of setting up a 4344mk11 crossover with the 2123H when the opportunity came along...... What I thought would be a quick job has taken a bit longer (as these jobs do).

No doubt trad 4343 owners will read these posts and wonder what all the fuss is about.

Well the proof is in the listening.

Hence I am reluctant to spend a lot of my own time and people's money on tarding up a stock 4343 around the edges.

[Chas]

I thought you had two systems.


Yes for two channel, and re-capped (Hovland) 4430's, doing HT duty.

[Robh3606]

Hello Ian

I am glad you like the 2123's. They certainly are a fine driver. Lots of work in those crossovers, they look good.

Rob:)

[4313B]

Hey G - whats the likelihood of movement on those drivers? Think they'll be shipped any time soon?The second coat needs to dry overnight. I did the first coat last Sunday night. I did the second coat this afternoon. I want to run curves on the two 2425H's mounted on 2307's and save the data for LEAP.

[4313B]

I want to run curves on the two 2425H's mounted on 2307's and save the data for LEAP.Impedance curves include one with an 8 ohm L-Pad set at 4 ohms / 13 ohms and a 16 ohm L-Pad set at 8 ohms / 20.8 ohms, roughly 12 o'clock. Easy enough to see how opening an L-Pad wide open would have an effect on any intended voltage drive.

[Ian Mackenzie]

Thanks.

I wonder what the LR 1.0 mH + 7.5 ohms does to the impedance curve?

Ian

[4313B]

Red is just the 2425H (L-Pad wide open). Blue is the 2425H with the 1.0 mH 7.5 ohm LR conjugate. The other three plots are L-Pad settings with the 3-2 wiper set at 2 ohms, 3 ohms and 4 ohms along with the conjugate.

The second graph compares the 2425H and L-Pad set to 4 ohms without (red) and with conjugate (blue).

[Ian Mackenzie]

Excellent.

[4313B]

Both pairs of aquaplased diaphragms shipped via U.S. Postal Service today. The Post Office had to "repackage" the pair going to Australia with "registered" tape and stamps so that one would know if anyone opens the package before it gets to where it's supposed to go.

[richluvsound]

Gents,

I took the tads out and put in the LE85 from the summit. The seal is still intact - original ali dia :D

I guess I'm saying this for next person that decides they must have the next big up-grade. It really is a fine sound as is. No eq , passive xo . The Ali is much warmer IMHO.

just my 2 pence worth.

Good luck with the project .

Rich

[JBLCanuck]

Both pairs of aquaplased diaphragms shipped via U.S. Postal Service today. The Post Office had to "repackage" the pair going to Australia with "registered" tape and stamps so that one would know if anyone opens the package before it gets to where it's supposed to go.

Can't wait to hear the fruits of your & Ian's labour Giskard....thanks very much for your help with the project! :)

[4313B]

Gents,

I took the tads out and put in the LE85 from the summit. The seal is still intact - original ali dia :DYou might want to pull the backcaps off and make sure there isn't a whole bunch of rotted junk inside.

[Mannermusic]

You might want to pull the backcaps off and make sure there isn't a whole bunch of rotted junk inside.

Happened to see the post - yes, are those old foam dampers (or whatever they are called) for the vintage drivers still available? If not, what's the recommended replacement? My 30 yr. old 375s are as you describe above! Mike

[richluvsound]

You might want to pull the backcaps off and make sure there isn't a whole bunch of rotted junk inside.


thanks 4313b . Are these the drivers with foam (once foam) in ?
I wont bother asking you which is more important - foam or seals lol.

Rich

[Ian Mackenzie]

I don't think its a plug and play situation.:blah:

In other words what one user may find using a driver diaphragm combination in one system may not apply in another.;)

The manner of the voicing is so sensitive that the charactertics of each driver depends on the other. Therefore component tolerances like the L dcr value in the UHF filter are critical to the subjective voicing.:)

Having said that the L pads are a lot more user friendly and I like the way the LR 24 db slopes work in this system. :bouncy:. In that respect the stock 4345 is far more difficult to set-up.

It will be interesting to see how the acquaplas diaphragms go.

All I can say at this point is that its worthy of a 4345mk11 designation.

[Mr. Widget]

Happened to see the post - yes, are those old foam dampers (or whatever they are called) for the vintage drivers still available? If not, what's the recommended replacement? My 30 yr. old 375s are as you describe above! MikeA couple of years ago JBL Pro still had 2440/2441 replacement foam pads available. (For those not in the know, these would be identical to later model 375 and 376 pads.) I don't remember the part number but it has been posted here... somewhere. :o:




I took the tads out and put in the LE85 from the summit. The seal is still intact - original ali dia :D
You might want to pull the backcaps off and make sure there isn't a whole bunch of rotted junk inside.:yes:

Or make sure the aluminum hasn't fatigued. :banghead:

http://www.audioheritage.org/vbulletin/showpost.php?p=249086&postcount=9



Widget

[4313B]

Happened to see the post - yes, are those old foam dampers (or whatever they are called) for the vintage drivers still available? If not, what's the recommended replacement? My 30 yr. old 375s are as you describe above! MikeI believe these are the only two left. Top one is the 375/376/2440/2441 which you have to cut down to fit in the LE175/2410/LE85/2420/2421.

60398 DAMPENER PAD, POLYESTER,GRA $6.18
61286 DAMPENER PAD, 2425 $2.94

There has to be a better material than this crap... it's real neato for a few years but then it goes rogue.

[Mannermusic]

I believe these are the only two left. Top one is the 375/376/2440/2441 which you have to cut down to fit in the LE175/2410/LE85/2420/2421.

60398 DAMPENER PAD, POLYESTER,GRA $6.18
61286 DAMPENER PAD, 2425 $2.94

There has to be a better material than this crap... it's real neato for a few years but then it goes rogue.


Thanks Widg and 43 - will ck with the local pro (SAS). Mike

[Ian Mackenzie]

While we are waiting for the diaphragms I have been evaluating the biamp active filter.

As it is nearly impossible to obtain meaningful spl measurments in a listening room and because a ground plane measurement is not practical modelling is a useful tool.

While a model can tell us a lot about the predicted response in the crossover region (without the usual room influence on measurements) subjective evaluations can sometimes confirm what we seen on paper. But I prefer to let the ear tell me there is problem first and then use modelling and measurements to determine what is causing the issue and hopefully provide a solution.

I did some simulations with 24 db LR slopes previously.

As a stock standard filter (see the Rane paper) its seems to provide the smoothest on axis and power response of all standard filters. The LR 12 db filters are almost as good.

Why is power response important in the vertical plane?

In the crossover overlap region 250-400 hertz the response of the woofer and the mid cone sum to produce a flat response where the drivers are electrically in phase and -6 db at the crossover point.

However due to the location of the woofer / mid cone in terms of the geometric location of the drivers on the baffle and their acoustic centres this results in a tilting of the vertical polar response in the crossover region. This is further complicated by the phase response of the crossover filter and the slope order.

The higher the order of the filter the steeper the slope and the spread of the response tilting is minimised. The steeper slopes also provide bandwith limiting of the woofer (into the midrange) and the mid cone (into the bass region).

This tends to narrow the range of of axis polar response tilting and limit the response of the drivers to their optimum operating range.

So what happens is that the reverberant field in the immediate vacinity of the system can be excited by the polar response that is projecting off axis (or more commonly called a lobe) response. The effect is that the power response in the crossover region will be unduely influenced and will be inconsistant with the on axis response. This cannot be fixed by equalisation.

Because this region supports the basis of the vocal range it under pins the midrange tonal balance of the system. While attempting to adjust for the right balance between the bass and midrange drivers you may find the midrange clarity masked by noise from "the reverberant field" where there is dominant imbalance in the power response. This may be seen on paper as a non linear +- 0.5 -2 db swing where the response in overlap region is beaming in an off axis direction.

It is difficult to make categorical subjective statements where a different mid range driver is in use.

However, the woofer/mid range transition seems to be better integrated and is easier to set-up than my historical impressions of the 2245/2122H using 18 db slopes. There being a far reduced effect for the system to bloom in the lower midrange/upper bass without the need for external equalistion while portraying a more decisive, crisp transient performance.

I attribute this to a combination of factors as mentioned above.

In this respect the system behaves more like 4343 in the mid/upper (chest hitting) bass region while projecting almost limitless authority in the lower registers.

I also found that adjusting the crossover point to about 350 hertz provided the best overall balance.

It may well be possible to improve the optimisation with a customised filter alignment but as a stock filter the LR 24 seem to work well.

I will look at practical trials of other filters shortly using a full adjustable class A active set.

Ian

[Chas]

Ian, once again, my thoughts are similar to yours. My RTA and ears tell me it's fine as well.



I also found that adjusting the crossover point to about 350 hertz provided the best overall balance.
Ian

I was thinking of trying something along these lines, (IE >290 Hz) but my crossover is a semi fixed frequency state variable and I have been too lazy to change out the resistor values. Thanks for posting your impressions, it might get me off my ass and try it.:)

[Ian Mackenzie]

The plan is to review the overall system this week.


-To date we are arranged 4344mk1 charge coupled crossovers.
_Acquired the 2123H mid cone drivers for use with the 4345 box.
-Acquired acquaplas coated DR82425 diaphragms.

I have also updated the series coil on the HF filter and the shunt coil in the UHF filter to the exact series DCR spec. Small differences in the voltage drives equate to a subjectively audible tonal balance (given that +-0.25 db variations are audible over broadband shifts in level).

This is why I take notions of plug and play with a grain of salt when dealing with a 4 multiway system. Unless the drivers all sing together its crap.

If time permits we will post some measurements and look at alternative active filter voltage drives.. There are basically 3 options, 24db LR slopes @340 hertz (in phase), 12 db LR slopes @340 hertz (phase reversed), 12 db modifed butterworth slopes @230 hertz LP and 300 hertz HP (phase reversed).

[Ian Mackenzie]

Placement.

In read the 4344mk11 manual the other night and realised I had not been listening to the system in the right location.

In the manual they advise your ears must be in line with the bottom of the lense. Intuitively I did this and it made quite a difference to the imaging (improved).

As mentioned elsewhere the 4344mk11 crossover transition from the 2123H to the horn/lense assemble is different from that of 2122H and horn/lense assembly used in the 4345.

I have not fully explored the technical aspects but it would appear the design point for the 4344mk11 mid cone - horn transition is more broadly between the horn and the 2123H cone than in the 4345 .

It could be said the 2123H is doing more of the work than the 2122H where the sound ultimately eminates from the 2123H dust cap as it reaches higher. As a driver like this goes up higher the power response drops off. To compensate the crossover is setup for the best vertical dispersion at a particular vertical postion. In the case of the 4344mk11 being on axis with the centre of the lense is less then optimal and ear height needs to be somewhat lower.

I digress that I previously removed the stands as they presented a danger to the user when attempting to move the enclosures.

The above should not be viewed as a limitation but more so the subtle nature of getting the best out of these designs.

Ian

[Russellc]

Almost finished the cabinets...I primed the backs & bottoms today...couple coats of satin black & some insulation inside & they'll be ready to start installing drivers & networks :applaud:http://members.shaw.ca/missionkraft/4345-103.jpg
sorry for the late intrusion, but a question please. Are the bottoms of these old monitors black paint, or veneer? I think I understand you to say the bottoms are painted?

Thanks in advance,

Russellc

[4313B]

After playing around with the stock 2307/2308/2421, 2307/2308/2425 as well as the "2313"/2308/435Be and 2311/2308/2441 for the last four years I decided to try out the H93/L94/2445. Greg talked me into the L94, it wasn't hard for him to do as I always thought it was a very nice looking lens.

I rearranged the baffle to my personal preference.

I wanted to avoid the foam rot issue by using the 2123H and modified 4344 MK II network but there really doesn't seem to be a viable substitute for the good old 2245H.

[BMWCCA]

What improvements did you realize from moving the ports? The alignment looks great, even natural. Does it improve the performance (beyond your HF driver choices)?

:applaud:

[Robh3606]

I decided to try out the H93/L94/2445.

Well that sure sounds like a nice upgrade path. Will a 2445 work in a stock box or would you have to go with a 2" NEO 2450??

Rob:)

[4313B]

What improvements did you realize from moving the ports? The alignment looks great, even natural. Does it improve the performance (beyond your HF driver choices)?

:applaud:Moving the ports theoretically reduces diffraction with respect to the 2122/2123. My main motivation was that I thought it looked better though. :dont-know

[4313B]

Will a 2445 work in a stock box??I don't really see how. It's a rediculously huge beast of a driver.

[midlife]

Moving the ports theoretically reduces diffraction with respect to the 2122/2123. My main motivation was that I thought it looked better though. :dont-know They look great, beautiful work.

[richluvsound]

Hi 43,Russell,

Beautiful work from both projects

Rich

[saeman]

That stair-stepped mid base box is sexy but come time to build it you'll likely not enjoy the extra work. Since you're baffle does not have the L-Pads and port tubes straddling the mid base box, you are free to make it as wide as desired.

The stock 4345 mid base box is too deep to allow using the 2445 land mine hanging on the 2311. It would be easier to make the box shallow enough to clear the 2445 and make up the lost volume in box width. I recall the factory box to be 6" internal depth. A new box 4 1/2" deep would allow clearance for the driver.

You have better resources than I do so check the best volume for the 10" er. I have found that the volume provided in the stock 4344/4345/4343 is larger than JBL specified as optimum for the drivers used. If that's true then making the box smaller should be no problem.

[Ian Mackenzie]

The other thing is the 2405 is mounted higher in the 4344mk11 on looking at the baffle.

I have my own theory on why that did that:wasnt-me:

Ian

[4313B]

That stair-stepped mid base box is sexy but come time to build it you'll likely not enjoy the extra work.The subenclosure step has a cradle on it to support the 2445. If I was building more than two of these then it would probably become irritating.
Since you're baffle does not have the L-Pads and port tubes straddling the mid base box, you are free to make it as wide as desired.I'm kind of hooked on the deeper as opposed to shallower subenclosure phenomenon.
The stock 4345 mid base box is too deep to allow using the 2445 land mine hanging on the 2311. It would be easier to make the box shallow enough to clear the 2445 and make up the lost volume in box width. I recall the factory box to be 6" internal depth. A new box 4 1/2" deep would allow clearance for the driver. Yes, it really is awfully large.
You have better resources than I do so check the best volume for the 10" er. I have found that the volume provided in the stock 4344/4345/4343 is larger than JBL specified as optimum for the drivers used. If that's true then making the box smaller should be no problem.Yeah, I'm pretty sure they were over-volumed, even taking into account driver displacement, with all that fiberglass stuffed in them.

Thick-walled sonotubes could be a subenclosure option. I used some many years ago for a few pairs of 2108H's to good effect.

The other thing is the 2405 is mounted higher in the 4344mk11 on looking at the baffle.http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=39670&stc=1&d=1243866649

[Ian Mackenzie]

I see why you wanted the 2311's.

I hope to post some measurements of the system next week using LMS4/LEAP pending the situation on the home front.... Chris Strahm CEO Linearx has been helpful in getting it organised.

Ian

[Ian Mackenzie]

I did some test measurements with LMS 4 this afternoon and will export some graphic files and
upload them on Monday and Tuesday.

[4313B]

I thought you took apart your 4345's awhile back.

[Ian Mackenzie]

They are still entact (my other project is paused so I still need something to piss of the local natives)

Here is a response test.

Nothing particularly scientific here.

It all seems to work.

LMS4. I can post the analyser settings if any one is interested.

Mic is located about 1 metre sinewave and 920 mm from floor (at level with bottom of lense non gated. Liberal use of 75mm 600 x 600 mm studio acoustic tiles.

Second response is smoothed.

At this distance the response is very mic location dependant so I would take an dips and peaks (particularly the dip at 1300 hertz) with a grain of salt.

Divisions are 5 db. Log scale.

I am very pleased with LMS4, particularly the Curve library and the accuracy of below 1000 hertz.

Room modes below 100 hertz can be ignored.

Ian

[Ian Mackenzie]

Below are some additional response test I ran this morning.

4345 full response - 4344mk11 network 340 hertz biamp with 24 db LR network

2122H response with filter L pad 0
2420 response with filter L pad 0
2405 response with filter L pad 0
4345 response high pass biamp

[Ian Mackenzie]

More additional response tests

2123H nearfield response (comparing left and right channels)
2420 nearfield response

*Note a legend error. 2122H should read 2123H

I do not have a full assembled original equivalent crossover network and a 2122H to compare response test but they are different.
Please note the test graphs are log scale and show more detail than typical linear scales.
5 db per division.

[4313B]

*Note a legend error. 2122H should read 2123H

I do not have a full assembled original equivalent crossover network and a 2122H to compare response test but they are different.So all these plots are with a 2123H instead of a 2122H? What network is being used?

What's up with the date/time stamp? :p

[Ian Mackenzie]

There are a few things to sort out.

The date was probably the last time this particular PC was used.

4344Mk11 network

Yes all 2123H

[Ian Mackenzie]

I don't have a lot of time at the moment for any of this stuff so I will keep it short.

Please refer to previous posts about the drivers and crossovers being used.

Marty enquired about how the auditions worked out which is what matters.

I used the system tonight with some Blue Ray disks encoded with Master Audio..Jeff Beck and some other stuff.

Put simply this system (2245H, 2123H, alnico 2420+titanium diaphragm with acquaplas coating and 2405/077) is significantly better in several area's than any previous renditions of any of the stock or diy JBL 4 ways I have heard to date.

The transient performance and resolving power is quite impressive and the driver integration appears to be optimised.

The 4344mk11 crossover network seems to bring the best out of the more contemporary revisons of the drivers used. It fair to say this system was voiced for the Japanese market (4344mk11) in that the system excel's on Jazz but then what real JBL isn't. The addition of the 2245H is the icing on the cake.

The message is its a no brainer to use the 2123H and the 4344mk11 network if you plan to update your 4 way crossover.

[4313B]

I'd call it a pretty nice option.

The 4344 Mk II network is definitely more along the lines of other advanced network topologies we've come to appreciate. The 3144/3145 and 3155 are the last of the tapped autotransformer era.

Many people still prefer the 2122H though. For that matter, the 2121/2121H still has a substantial following. JBL can't keep those recone kits in stock! So it looks like the old 3140, 3141 and 3143 are going to be around for awhile too, not to mention the 3107 which people still seem to love.

I am quite happy with your report. I guess the next step for me is for me to put a "package" together for Bo to give a whirl. I'm not real inclined to build TWO pair simply for A/B comparisons. I suppose Rick might be up to it.

[Ian Mackenzie]

Like any loudspeaker no two designs are alike and over time people develop learned preferences.

I have listened to the stock 4345 (diy) for around five years and in the case of the 2122H I agree it works best with the stock network (charge-coupled) and the non treated titanium diaphgagm or aluminium.

I have also used the acquaplas treated diaphragm extensively and while it offers benefits with its inclusion I now don't think this application was optimised for the 4345 system overall.

This is quite obvious when a Be or other driver is compared to a JBL driver substituted with the acquaplas. Some people have opted for a Be driver over the acquaplas after auditions.

In the case of the acquaplas treated diaphragm based on observation the 4344mk11 network provides more consistant spectal balance and transient resolving power in the transition to the 2405/077.

Why?

We need to look at how the acquaplas modifies the characteristics of the driver and how manipulating the voltage drives can compensate.

The acquaplas basically damps the diaphragm resonances and we loose about 1 db sensitivity overall (not much). My theory which I can support with subjective comparions is that by adding mass (the acquaplas) to the diaphragm we damp some of the resonances but the driver tends to operate in more of a "mass" loaded operation at higher frequencies and this tends to tone down the transient or spatial performance.

What happens with the voltage drives in the 4344mk11 the horn is let run out in the top end with only the 0.24mh inductor while the 2405/077 is bought in harder as can be seen by the Q of the filter.

In comparison the stock 4345 network has what might be called "sharper" transitions using a non damped diaphragm where the diaphragm is using its own self resonance at higher frequencies. The result is a balanced spectral transition to the 2405/077. With stock network and the acquaplas damping the spectral balance is un even and the 2405/077 only adds the extension.

While both the 4345 and (also the inclusion of the acquaplas) 4344mk11 measure similarly to my mind the 4344mk11 network brings back the "life and air" of the stock 4345 but is more refined and with it sharper transients. The transition from the mid cone to the horn has a better timbre match in the 4344mk11.

This is why you can't just design around voltage drives in the hope it will turn out right. The stock 4345 was emperically designed as I understand it and I have no doubt the ears had a fair hand in how the 4344mk11 turned out.

[4313B]

With stock network and the acquaplas damping the spectral balance is un even and the 2405/077 only adds the extension.I haven't noticed any problem other than that the stock network sounds dead to me compared to the biased equivalent. The aquaplased diaphragm performs exactly like Greg suspected it would.

I'm extremely happy with the way the 4345 and 4355 have responded to the updates. As far as I'm concerned they've actually become viable again, so much so that I've decided to bother with building my own "best of breed" pair just for pure grins.

They are rediculously large but the updates make the size more tolerable. They have a visceral impact that the stock Everest II just doesn't have. I can see why they are still so incredibly popular, especially given that they are so inexpensive to obtain.


This is quite obvious when a Be or other driver is compared to a JBL driver substituted with the acquaplas. Some people have opted for a Be driver over the acquaplas after auditions.That would be the TAD?

[Ian Mackenzie]

I guess size does matter.

I think having to resort the Be (Tad) kills the whole point (financially) of attempting to own or build a pair of these 4 ways.

People tend to be seen as an elite-ist once they start preaching that sort of thing as an only option which is utter bullshit (when the capacity to optimise a system properly is not available or beyond their skills level)

My coments were in reference to my own iterations and auditioning Bo's 4345 (Tad), Saemans stock crossover repo 4345 system and Rich's CC diy 4345 with acquaplas. I recall Rob also commenting regards Be - acquaplas differences when I was in NY.

If you had heard nothing else (which is essentially the case for most here) you would be quite content with a stock 4343. Then try a 4345 and things are different and so on. I prefer a stock 4343 to a 4430 (when properly set-up) but thats just me.

[boputnam]

Here is a response test.Hi, Ian...

This is all quite interesting.

Remind me of your signal path? What is the active crossover being used, and what are your amps?

Great response curves, btw... :)

[Ian Mackenzie]

Ah,

Bo my friend.... it certainly is an interesting topic.

The graphs were in the room. Nothing fancy just common sense.

I guess my point was/is that a flat response does not mean you will get actual detail (remember those Eq'd out horns flat to 20,000 hertz in other threads.

The 2405 in the 4344mk11 seems more active in its role and I like the end result. On the sweeps I can hear it (sweeping from top down) at 16,000 hertz.

If the curves below were normalised in the link below you would see a net increase of +5 db at 11 khertz. The 4345 filter being -3 db down from the flat voltage amplitude and the 4344mk11 filter being +2 db up from the flat voltage amplitude. That in my book be very audible and can be seen in measured response in the second link. If you look at the 4343 voltage drives its has an even higher Q and is sounds more agressive at 8000 khertz.

http://www.audioheritage.org/vbulletin/showpost.php?p=247755&postcount=6

http://www.audioheritage.org/vbulletin/showpost.php?p=259248&postcount=129

Another dimension of the analysis is the power response (off axis) of the 2307/2308 which is well documented. The power response falls of progressively at higher frequencies for this assembly. The 2405/077 on the other hand has a much wider power response in the 7-12 Khertz area.

Not wanting to be a stickler for detail but I think it worthy of some discussion aside from what are the well known and respected upgrades. If I can determine something sounds different I like to intuitively investigate why.

Amps Pass labs. Loads of resolution there.

Active Crossovers Passlabs / DBX.

If I get time I will hook up an original equivalent filter on the horn and the 2405 and compare.

[JBLCanuck]

I planned on having these done months ago but I got real busy this past Summer & so speakers had to go on the back burner :(
I finally got them insulated & my foilcal's, velcro & grills installed, now just a few things to get mounted & sorted with the Networks & we'll be in
business :applaud:
Has anyone got an email address for Ian MaKenzie? The one I have isn't working & I have a few questions for him regarding hooking up his Networks.
Has anyone got any better ideas for the Network 9v battery? I was thinking a better idea would be remove the battery from the network & relocate it to the bottom of the speaker. There's plenty-O room under there for it & it just seems like lots & lots of work having to remove drivers to check/replace a simple battery....no :dont-know
Anyway...here's a pic of them wearing their new "Wrap On" insulation...that's an ugly job once they're all assembled but that's really the only way you can do it.
Thanks for everyone's help :)
http://members.shaw.ca/missionkraft/IMG_0265.jpg

[timc]

Very nice craftmanship!

When are you hoping to put sound through them?


-Tim

[Chas]

They're coming along great, for sure. Good idea, re. installing the battery underneath.

[BMWCCA]

Has anyone got any better ideas for the Network 9v battery? I was thinking a better idea would be remove the battery from the network & relocate it to the bottom of the speaker. There's plenty-O room under there for it & it just seems like lots & lots of work having to remove drivers to check/replace a simple battery....no :dont-know When I got my 4345s from NewZenith the Dave Brink-built CC networks were external to the cabinets on an MDF plate with the 9v mounted to the board using NL8s to connect them to the bi-amps. I removed the woofer and mounted the board to the inside-bottom of the box, on rubber isolation feet, ditched the NL8 connection and cable, and used a Parts Express input cup already rigged with dual input posts for Pomona plugs mounted to a recessed MDF plate Brink had used to seal the "original" style network opening, but I painted it to match the black of the cabinet backs. The input cups look pretty JBL-ish to me and came complete with gasket:

http://www.parts-express.com/images/item_standard/260-304_s.jpg

Now I simply remove the four screws and pull out the plate to reach in and change the battery. Which I've decided to do on an annual basis, coming up. When I do, maybe I'll remember to take photos.

[Ian Mackenzie]

The battery will last its shelf like so its not like it needs to be accessable really. The whole mess is made to be connected and left alone.:D

Your schematic in the email looked accurate.

[BMWCCA]

The battery will last its shelf like so its not like it needs to be accessable really. The whole mess is made to be connected and left alone.:DI'm using Duracell Procell 9v (same thing we use in our Shure wireless mics) which generally have about a 4-year "use before" date window. I'm still going to check them at the one-year point to see how they're holding up. Because I can, and because I've made it easy to do. I change them in my smoke detectors and CO detectors annually, too.

Especially after last week: http://www.readthehook.com/blog/index.php/2009/10/23/drummer-lost-fire-victim-was-johnny-gilmore/#at

Public service announcement: Make sure your smoke detector is not an ionizer-only type. Use only the photoelectric or dual-mode types if you want to save a life.
http://www.readthehook.com/Stories/2009/01/22/COVER-FIRE-VINTON-MAIN-D.aspx
I changed all of mine last year.

[Ian Mackenzie]

Ah,

The mid, horn and slot have the wiring polarity is reversed after the L pads per the original factory 3145 crossover schematics. Therefore don't forget to reverse the woofer polarity if you plan to use LR 24 db active filters......

Oh no not that polarity thingy again...Muhhahaha!

[BMWCCA]

Ah,

The mid, horn and slot have the wiring polarity is reversed after the L pads per the original factory 3145 crossover schematics. Therefore don't forget to reverse the woofer polarity if you plan to use LR 24 db active filters......

Oh no not that polarity thingy again...Muhhahaha!Here we go again with that great maxim concerning the English language and its usage: "The first failure in communication is assuming any is taking place."

Heck, I can't even tell to what post you were replying! Random? Private e-mail? Problem with the network? 9v battery issue? :banghead:

Reminds me of the old comic book, "Tales from the Cryptic"

:D

[Ian Mackenzie]

I was replying to Marty's numerous pms and emails (not you..my pmbox is 100%) that I have not had an opportunity to reply to individually ..this step in assembly of the networks is easy to get wrong and advice is best sort from the builder hence its worth posting.:help:

This is a lot taking place..its just not possible to post everything here at the moment.

[dkalsi]

I planned on having these done months ago but I got real busy this past Summer & so speakers had to go on the back burner :(
I finally got them insulated & my foilcal's, velcro & grills installed, now just a few things to get mounted & sorted with the Networks & we'll be in
business :applaud:
Has anyone got an email a
Any update on your project?

[Ian Mackenzie]

Ditto,

I would also like to know how it turned out given the time and expense in preparing those networks.:)

Ian

[Ian Mackenzie]

Hi have sent an email to Marty for an update

Hopefully we might see some images of the system installed.


I have a sister system (using the 2123H) and intend to fit a Tad 4001 driver with the 2311/2308. Aftermarket Be diaphragms maybe an option for those interested but the passive filters will need modification. I have Leap V, Sound Easy and LMS so its not that difficult.

Pending how it goes I may also mess with some other ideas like conical horn loading the 2123 to enable time alignment of the mid cone.The 2123 loads up very well on a suitable horn.

Still in the works is a dedicated class A active crossover using a double sided pcb.

[Ian Mackenzie]

As a post project idea I have ordered an eliptical wave guide XT 1086 to experiment with the effectiveness of constant directivity.

One of my pet hates with the 2307/2308 is the non linear directivity at higher frequencies . Attempts to toe in the enclsure for more balanced on axis response does not work. I figure if this idea works for me some others in diy mode may also consider it .

The XT 1086 is a wave - guide of elliptical design and produces a spherical wave front with low distortion. The size of the wave - guide also has some practal benefits

Previously I have used the 2344 100 x 100 bi radial with v.good results. Perhaps the only down side was the wider than required 100 x 100 dispersion

The XT 108 has constant directivity 80 H x 60 V from 1.4 to 16 K hertz and with a crossover point of around 1.5 khertz it should match the directivity of the 2123H(according to Rob's 2123 simulation)

The XT1086 will initally be trialled atop the 4345 box but if its promising I may install it in place of the 2307/2308.


http://www.eighteensound.com/index.aspx?mainMenu=view_product&pid=178

[pos]

Why not use a rectangular PT waveguide? The apparent dimension would be similar to a 2307/2308

[Ian Mackenzie]

Why not use a rectangular PT waveguide? The apparent dimension would be similar to a 2307/2308

This is a 1 inch throat wave guide

I don't have a 1.5 inch throat driver..I mean if a JBL 0476 was avaialble I would be using it