This thread is dedicated to discussion, (questions, feedback, opinions) of all aspect of the project involving the project design and description thread.
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This thread is dedicated to discussion, (questions, feedback, opinions) of all aspect of the project involving the project design and description thread.
This thread is now open for discussion.
With respect to the photo above - What a mess! :rotfl:
Common guys, I know you all can come up with a better baffle layout than that!
Apply everything we've gone over on this forum the past five years and build something killer.
I look forward to seeing what you guys come up with.
Hi, Ian.
Can you start out with a basic description of the two systems, please, and why one might want to upgrade?
I don't know a 4344 from a hole in the ground.
[OR a 4343 from either, for that matter.... :o: ]
We've gone over it numerous times... what a waste of my time THAT obviously ended up being... :applaud:Quote:
Originally Posted by Zilch
Naw, so much the easier, then: Ian can LINK us there! :bouncy:Quote:
Originally Posted by Lancer
[An introductory overview would be helpful, is all....]
Definitely food for thought. I wonder why the 077's are so stinking close to the lenses. You'd think that there might be some interaction between the two, giving the 110 degree dispersion. I might have spaced it out at least a few inches or better yet, put it on top like the L-300.Quote:
Originally Posted by Lancer
Here's my idea of an improved layout. Ports in back, drivers in line and offset on the panel mirror imaged. No equal spacing between a driver and a sidewalls. No protruding edges where the grill would mount. The 077 and Lense were kept side by side. The serpentine lense has the same patern for less depth and is low enough that I don't think it interferes with the 077. I think it's look better too:D.
Rob:)
:rotfl:Quote:
Originally Posted by Lancer
maybe we should look at something like this idea instead... :DQuote:
Originally Posted by Lancer
Ian, I hope you keep the 2121 in place. Ripping out nice cones and replace with 2122 kits is not everyones thing.
I think we should remember that the 4343 was designed for mixdown studios and, though it could be used vertically, was primarily made to hang horizontally above the board! The baffle layout was made rotatable to allow these orientation options and was probably compromised slightly due to this. The 4344 didn't have these requirements. Also, the 4344 came a bit after the 4343, so any new technical understanding could have influenced the subtle changes (or refinements). Some of these new understandings were seen in driver and crossover improvements.
Though I don't hear any significant defficiencies in my 4343s, I have thought about how I might improve things if I were to build an updated pair.
I think I would basically go for the 4344, but would have to consider other questions...like the idea of using a pair of woofers in each cabinet to improve and tighten the low end. I suspect the 2123H would be a stronger mid driver. Maybe a wood horn, or even going to a 1.5 or 2" throat and a 4" diaphragmed driver... maybe even the TAD 4001...? (I suspect the 2405s would stay though)
Ah, see how it all grows?
Maybe simply rebuilding my crossovers for the mid/high/UHF sections in my 4343s would really be enough. ?
This is why I look forward to the development of this thread!
Tom
I see you are the one who desires the modifications thread.....Quote:
Originally Posted by Lancer
That picture was sent some time ago to me by Rob.....yes he is responsible...Lol
Okay,Quote:
Originally Posted by Zilch
I suppose we are appealing to existing owners, or those who have traded their 4343 and after reading the forthcoming wish they hadn't.
The Library has ample information on the 4343, and the JBL system guide has details of the drivers of the respective systems. We will compare the two systems and then discuss the various upgrade steps.
I have not literally had a 4343 and 4344 side by side, but I can say the updates not all of which have been made public yet in a "condensed engineering format" do impart refinement and improvement over the 4343.
In the development of the project we also discovered that despite popular opinion bi amping will not necessarily provide improved Hi Fidelity.
What we do here will be the icing on the Cake among other special fgoodies that will be rolled out in the project.
A system only works as well as the sum of its parts and we will discuss how a total system can perform beyond your wildest dreams!
Ian
Interesting observation.Quote:
Originally Posted by Regis
While measuring the system I found the lense has a dispersion of around 80 degrees, the published polar pattern illustrates this. Looking at the system with correct orientation there is a clear line of site to the slot opening. I will publish if you like measurements of the slot with/without the lense.
I tend to think the two devices work well together "when" adjusted correctly.
The mirror imagine pairs with the slot on the outside does have a significant impact on the imaging. At the crossover wavelength both should be as close together as possible.
Ian
Rob your being a show off but I like it...I know you can take that as a joke.Quote:
Originally Posted by Robh3606
Well we will talk about a new upper baffle, all the stuff's got to fit somewhere.
The important thing is the offset and non equidistant path lengths.
We had not considering re building new enclosures but I suppose that would fall within scope if those daring enough saw fit to rebuild their 4343 or clone a 4344.
So this will become a real hands on project where members can apply their skills and share ideas., not a chat session.
Ian
Ian
Good point.Quote:
Originally Posted by Guido
While out upgrade steps will be clear, concise and distinct.
he individul can of course decide on the degree of enhancement to his/her 4343 system
Be aware however that it will not be a 4344 (spec) and some juggling of the crossover will be necessary if you mix some of the drivers and not others.
Part 9 of the upgrade will also discuss use of modern drivers!
Ian
Here is the Project Framework.
We spent a while listing all the possible combinations and then rationalised it into these steps.
While not set in stone, the scope of any project has to be clearing defined from the outset, but in any case I think we have most of the bases covered here.
By the way porschedpm wrote the script, no doubt he will come in soon.
Feel free to comment.
Ian
Hey that's what was intended on a previous attempt to out do JBL, lets please not have an open ended situation...we all know where that can end up..:rotfl:Quote:
Originally Posted by Lancer
Lancer you've just been promoted to Head of Special Projects
- Part 9 Discussion on upgrading to modern drivers
I really look forward to the development here.
Maybe get some ideas to improving my DIY's.
A couple of photo's to compare the baffle layouts. It looks like the 4343 top baffle and bottom baffle could be redone to change the layout. Just set them up off center so the spacing is not the same edge to edge. Take a look at this pirated photo from another thread. Not to sure about the recess for the 2420?? If there is a plate it could be repositioned. Looks to me like the hardest part would be finding someone to mix the JBL Blue. At least with this method you would not have to rebuild the cabinets for a layout change. Just food for thought.
Rob:)
Ah ,
Bo's in charge on The JBL Blue Paint Mixing and Jean is The Sand Man.
Ian
Seriously i don't think it would be that difficult to make a new upper baffle, with accurate dimensions and a router jig it could be done.
The entire baffle would need to be re painted.
Heck, why don't we mass produce new baffles....The Widget...where are you!
Ian
IMHO it should be relatively straightforward constructing a new top baffle and deserves to be added as one of the modifications. Blue paint should not be a problem thanks to Bo's successful quest for the correct mix and his community outreach program for teenage paint store employees. I think one of the bigger challenges, though, would be getting a 4344 vertical foilcal produced. Unless your willing to go nude in this respect.
I'd be inclined to leave the bottom baffle as-is since it's permanently affixed to the cabinet and the risk of damaging the cabinet outweighs the benefit that might be gained. IMHO anyway. One of the parameters Ian and I set forth in our framework for this project was that any modifications could be easily un-done or reversed to bring a modded 4343's back to original spec or at least original appearance, due to the relative rarity and rising values of original condition 43xx monitors. Not that any of us are willing to part with our babies, but being these large format monitors are an integral part of the JBL heritage, I feel it is somewhat our responsibility to promote keeping these close to original. I think we're all looking for that next tweak that will bring us closer to musical nirvana but I also think when you're hot rodding a pair of 30+ yr old speakers you can reach a point of diminishing returns where it may be better to start with clean sheet of paper.
Hi Ian: If you need someone to make a pair of modified upper 4343 baffles, let me know. I have some left over 1" P.B. from my recent 4351 project. Send me a layout with desired dimensions. Would also need the dimensions of the mid-base box. Regards - Rick
Hello Ian: Thanx for getting this thread started - I'll be following it closely and will contribute what I can to your effort however I have no experience with the 4344. I do have a few questions.
Does anyone have the factory dimensions for the 4344 cabinet??? The 4343 cabinet is 41 3/8" H x 25" W x 15 1/8" D w/o grille. The 4344 MKII is the same. Can I assume that the 4344 is the same too? Is the mid base box for the 2122 the same volume as that for the 2121? What is the diameter of the two ports and the duct tube length? Those are easy questions, right !!
I started to cut wood for a pair of 4344's some time back but then put the project on hold. I was planning on starting up again and got a bad report on the factory baffle layout from Giskard. I have since layed out a new baffle resembling the one posted by Ian in an earlier thread, with 2235H non-equadistant to the cabinet sides. I'll hopefully build the cabinets this fall.
I'll be able to follow this discussion thread during my cabinet construction and throughout my hunt for components. I will no doubt end up with a better pair of 4344's as a result.
http://audioheritage.org/vbulletin/i...lies/smile.gif Rick
Thanks,Quote:
Originally Posted by riessen
That will be great!
Ian
Lets just look into this fine detail,Quote:
Originally Posted by riessen
Thanks for your input and enthusiasm
regards
Ian
We also plan to look at the whole biamping scene.
There are pros and cons for both conventional passive and bi amping.
In fact I intend to subjectively compare the JBL 5235 very shortly to a hi quality discrete class A crossover and conventional passive mode.
Ed will also describe no doubt his intitial impressions of a full passive crossover after using an Ashly active crossover in his system.
Ian
Ouch!Quote:
Originally Posted by Ian Mackenzie
We've discussed the 5234A and 5235 before along with how to improve them. One can easily hear why JBL used passive high pass filters in the BX63 and DX-1 once they hear a 5234A or 5235. ;)
this is a good thread because, having no experience with this monitor, (except lusting after a pair) i have imagined how i would line up various combinations of drivers and positioning. i would go totally in line, perfectly symetrical if space allows. i always imagined a 2441 in place of the 1". the great thing about JBL, that i'm sure you can all relate to, is that each series of driver has an identifiable aural signature with a common heritage...they share similar acoustic properties that can be molded into a musical instrument...a work of art really. the wife is having a hard time with the 'art' part. i look forward to following this thread.
p.s. for the sake of new members who are starting to discover this site, it would help if those of you who have been around for a while not spoil it for us with comments like, "we've discussed this so many times before." it's dissappointing when a thread is prematurely ended...it's all new to me.
[QUOTE=porschedpm] I think one of the bigger challenges, though, would be getting a 4344 vertical foilcal produced. Unless your willing to go nude in this respect.
I can get foil cals done in .022 stock without serial #'s for about $50 a pair when ordering 10. I had some done for 4343's. Of course an original is required to make a copy.
Edit: Nudity should be reserved strictly for the use of "buttcheeks." Whether they be small, medium or large is by personal preference. I prefer them all... nude, of course.:bouncy:
Yep,Quote:
Originally Posted by Lancer
Well as stated in post 13 by adopting a system this approach ensures the system bring the some of all components does infact add, not subtract to total performance improvement.
I tend to think this in many ways is what implementing and getting the best out (not designing per say) a hi performance speaker is about.
It is easy to modify and go the minimalist route but not end up with the right specification.
But if engineered correctly one can extract the right level of performance.
I bought yesterday some 0.018, 0.12. , 0.33 , .033 polystyrene capacitors to build an 18 db unity gain crossover. These are very large values of this kind of capacitor. I also intend to try charge-coupling the small signal electronics.
These parts will also be used in the 5235 cards to assess improvements to the 5235 crossover. I am sure there are members out there who will desire a better way of bi amping
I want avoid using the term tweak in the project. It conjures up the impression or interpretation of modification or change in the specifications and is too general. Tweaking is often a change to ones liking (not to be confused with taste but rather wanking) rather than a technically desireable improvement.
Of course one can individualise what steps will be taken to update to 4343 per the project framework.
Ian
Below is a distortion graph of a new prototype active crossover. The 4344 crossver will be less is more (better again) and built for the purpose.
[QUOTE=norealtalent]Very good, we will have to keep you in mind.Quote:
Originally Posted by porschedpm
Ian
Welcome Tom,Quote:
Originally Posted by Tom Loizeaux
Don may be able to confirm this but the 4344 was sold largely in Japan for the domestic audiophiles over there. A sub like the 1500 may be a worth option..Lancer may have input on the as things pan out.
About the steps to improvement, I don't think we need to take extreme measures. Of course a rebuild of the enclosure would be an option if you prefer to keep your original 4343 as is.
Ian
Documentation with references to both the 4343 and 4344 is an important part of the project.
If someone can post some links (ie the library and key threads & posts, jblpro.com, 4343 reviews) we will have a means of accessing important data.
I know myself I have previously posted some drawings and other also, so we need to locate and review these posts.
Thsi information once verified can be posted into the design thread. will start on this over the weekend. I suggest we all have a look around and come back with some links.
Ian
Hello Ian: Please take a look at the enclosure cutaway that I am planning for my hybrid 4344's. It's to approximate scale but just a sketch. My plan is to provide a recessed area at the upper rear of the cabinet to house all of the electronics related to the crossovers. All components, with the exception of the baffle mounted pots, will be outside of the pressure hull. I may leave this area open or possible provide a removable cover. To make up for the loss of internal volume I increased the cabinet depth 2". The resulting internal volume is near identical to the stock 4344. From the front it's height and width will look identical to the factory 4344. My question is "To all of the custom x-over guys out there" - Is there enough room in this area to house the necessary x-over components - coils, caps, gadgets, dugans, etc. ??? Assuming replies to the positive, I want to push on cutting wood and making the cabinets. Thanx in advance - Rick
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Very interesting Rick and mounting the crossover outside would make it easier to do mods on the X-overs, plus you'd have unlimited room out the back. I'm curious as to how you'd run the wiring from the external to the internal and whether or not it would have to be sealed or would you use connectors (like we do in areospace) through the 'bulkhead'? Secondly, if externally mounted, would you go with some kind of wire cage to protect the passives from any thing falling into them? Hoping a little forward thinking before cutting would help (even with my limited experience).
Thanx for the thoughts. For the wiring to the three pots I would use a single Beldon type multi conductor cable, like JBL uses, and a single penetration into the cabinet using a compression type connector. For the wiring to the four components themselves I thought an array of threaded copper studs thru the back might be a good thing. Arrange them 2 wide x 4 high, a pair for each component. They could easily be sealed at their point of penetration and nuts/ring connectors would ensure a good low resistance connection. Just my thoughts at this time. Keep in mind that I don't know diddly about custom x-overs.Quote:
Originally Posted by Regis
Interesting idea Rick,
Your design criteria has many of the ingrediance that "we" discussed when evolving the reference system for Ed.
When we thought it through it became clear that a new 3145 network would best be external to the crossover The reason is where would the network go in inside the enclosure and we wanted to leave the original crossover/wiring/L pad entact per Ed's comments above? That is the changes should be reversable(the Pads would have to be replaced for the 3145 network)
Secondly, how to organise the wiring to ensure a neat air tight seal and avoid the phase errors that can easily occurr with a 4 way system. What I came up with was a nice 8 pole speakon sock and plug . This plug accepts up to 13 gauge wire.
The solution was an external crossover about the size of a PL mini tower with the L pads on the front of it.
I like your idea but it will require a re build of the enclosure. There would appear enough surface area.
Are you making your from baffle removeable or the rear panel?
Ian
Ian: Neither the baffle nor the rear panel are removable. They are glued solid into the sides, top and bottom. Why do you ask ?Quote:
Originally Posted by Ian Mackenzie
Rick,
I will post these drawing at least temporarily for you to down load.
Please check the dimensions for accuracy before cutting.
Ian
The other drawings are here.
Ian
Ian: Thanx for the drawings. I think I downloaded most of them from one of your earlier threads, however I just downloaded them again. On these details I do not see the depth of the mid-base box or the diameter of the two baffle ports. Is this info listed elsewhere?? Thanx - Rick
Here it is.
I am not sure about the port length....I amsure its around in one of the many threads earlier on
Ian
Well some how you will need access to the compression driver and slot otherwise it will be almost impossible to remove the driver if it requires servicing.Quote:
Originally Posted by riessen
The same applies to the 2405.
I don't know about the 4344, but the 4343 had a removeable front baffle and the 4345 has a removeable rear panel for this reason.
Ian
Ian: I've never been a fan of a screwed down baffle. The two pairs of 4343's I've owned had their upper baffle sections removed some unknown number of times. The screw holes were deeply recessed into the wood and after a while the screw threads get stripped out. Removable rear panels remind me of most of Altec's cabinets, not made near as well as JBL's. The enclosure integrity is always at stake. Sealing tape is required and it just seems like a hassle.Quote:
Originally Posted by Ian Mackenzie
Consider this option - My baffle is very similar to the one you posted in this and other threads on the 4344. Between the compression driver and the woofer cutout there sits the big obstacle of the mid-base box. You can however take the driver/horn in hand and reach around the mid-base box. If one lacks the arm strength to lift/hold it into place until the screws are installed there's another little trick I learned from other projects. With one hand put the horn in position and using the other hand reach thru the cutout and stand it up under the hole. Take two pieces if 1/4-20 threaded rod with an "L" bent on one end and insert them thru two of the 4 mounting holes in the baffle and screw them into the horn. Then use the rods to pull the assembly up into place. Put the two opposite screws in, remove the rods and install the other two screws. The 2405 presents no problems with your baffle layout.
Is all of this anal - maybe to some. Building a box with all panels glued and screwed solid and doing business thru the baffle cutouts is always a better choice. Looking at everything JBL made I'm sure that this method was their first choice. If you don't have strong kids with long arms to help you can always bend up a couple pieces of threaded rod and do it by yourself. Coz the kids aren't always home I have rods too.
Take a close look at my 4351 baffle layout and see if you can figure out how I can get the 2440 and 2405 in and out of the cabinet, based on where they are located relative to the mid-base box and the duct tubes.
Not trying to be a smart ass but if there's anyway you can get around building an enclosure with removable panels - you should do it. My 4351's were a challenge in this arena. Rick
I suppose that would work.
In the drawings I posted there is a rear panel bracing.
I used this in my own 4345 clone and there are no issues with integrity of the enclosure. I use furniture grade flat head bolts with captive screw-in inserts in the hardwood frame to pull the removeabe baffle hard down on the medium density rubber gasket.
The removable baffle is about 12 inches high x the width of the enclosure. In fact I would say with this particular arrangement where there are two vertical 1x 3 inch braces and a 2 x 3 inch cross brace and also 2 front to rear braces adjoining the Dog Box and the rear panel make it more inert than a single large baffle......but whatever......
Ian
Hello Ian: I finished looking over your drawings and have extracted the info I need. Will try to start cutting some wood here soon. Although I'm not fond of having the rear panel removable, I do like the thought of a removable panel section and the framing necessary to provide it does beef up the rear panel. My 4341's have an upper removable panel to allow access to the mid and hi drivers. It is tastefully done and the cabinet rear is still good and solid. I'll chug along with the project and see where I end up. The cabinets are the easy part. Still need to locate some of the components (the 2122's should be easy to find, growing on trees I hear - ah, um, blah, ???, etc.) and will also try to work with someone more knowledgable than I am to get the x-overs built. I suspect this will be an on going and long term effort. I appreciate your comments and will keep you posted as I progress. Thanx - Rick
Rick,
At this early stage we are merely gathering opinions, data and resources, pop in and say hello as you please.
As each stage or step in the frame work is completed in the bhow to guide permanent data will be posted to the design thread.
Obviously members will pick up the project as you have done at a particular point and we wll do our best to accommodate you needs. We plan to progress through the steps as previously advised as this is the most logical approach.
Ian
One of the things I am mindful of is the question "what can I expect from these changes" particularly in reference to steps 5, 6 and 7. And not everyone one will be keen to starting making updates without some knowledge of the gains or improvements.
This has not been an easy issue to provide specific answers on so we been doing some very interesting tests and comparisons.
First off, we need to look at the 4343 in terms of its have's and have not's and in order to see what is going on in the system this means operating it at its basic level. This means full passive mode.
So Ed and have been doing some listening comparisons to arrive at some conclusions and applying the results to the technical side.
Step 4 has not been fully explored however working on the premise that good terminations are vital any unnecessary switches should be removed from the signal path.
To test this I placed a heavy duty jumper lead with crocodile clips in series with the positive input to the crossover network and did some blind test comparisons.
The cable was pure OFC and terminated to a Cardas hi quality binding post.
Inserting the jumper lead in series with the crossover and the amps caused a loss of low level information and the sound stage collapsed and sounded flat and planar.
So, while cables are often the flavour of the month in audiophile chat rooms please be aware that it's the terminations that are the final arbitrator of conductivity. Hence, a switch or other brass contact, oxidised or otherwise will downgrade the purity of the signal. Think of the amp as your car battery and the speaker as the starter motor.....its a good analogy.
Good terminations...we will discuss this in more detail in step 4.
Step 5. Upgrading the stock crossovers. This is the most popular issue and also the most expensive and controversial update for anyone contemplating a speaker restoration or a new design.
Again, we have organised some comparisons and have come to some conclusions. Some of these comparisons were conducted with the 4343 system and others simulated using the reference system the 4345.
Specifically in the 4343 the 3143 crossover has the midrange, horn and slot signal routed via a 52 uf capacitor in the midrange bandpass filter.
This was done according to JBL to improve the protection to the compression driver and slot from amplifier turn on/off transients. In the early days this was a problem but with modern amplifiers it is far less of an issue.
In a recent comparison with the reference system I was able to determine that the arrangement of this capacitor does cause a loss on information to the compression driver and slot. Specifically a loss of ambience and very fine details....much like a more polite but otherwise muted sound that lacked snap and dynamics. The series capacitor was a Solen polypropolyne metalised film foil bypassed with a 0.1 Solen film and foil capacitor (not charge coupled). The amplifier used was a Passlabs Aleph design.
By removing the capacitor entirely and putting the system in bi amp mode using a very special, and hi quality active crossover we also observed marked improvements in midrange clarity, transparency and improved purity. This was very noticeable on vocal harmonies where individual voices could more easily be identified. The active crossover used in this comparison is a discrete class A unit with a Passlabs Aleph amplifier on the highs and a PSS 600 amplifier on the lows.
We also observed that the 4343 in full passive mode can perform better than in active mode and the determining factor here is the performance of the active crossover and the amplifiers. Again a loss of information lead to less realistic results in biamp mode while the bass was more detailed ahd more authority in bi amp mode. The crossover used in this comparison was the Ashly analogue unit using a Passlabs X 250 amplifier on the lows and Mac amplifier on the highs. A Passlabs X 250 amplifer used in full passive mode.
So we can see that by reviewing the crossover network, the manner in which it is arranged and the use of a hi quality active crossover will yield a net improvement in musical performance.
Details of various upgrades will be discussed in step 5.
Step 6 Biamping Pros and Cons
Refer to step 5. The pros are improved bass clarity and authority. The cons are loss of transparency, imaging and information. The extent of the later will depend on the active crossover in use. Analogue active crossovers a deemed better and more affordable for home use than pro audio digital active crossovers. However budget prices will only buy budget performance in both cases.
Crossovers available on the Market.
Well there are dozens from entry level units like the Ashly, the JBL 5235, the Bryston and the Passlabs. The last 2 are premium grade but aren't cheap. Please note 4343-4343 does however require a specific crossover characteristic in order that the system works correctly.
I may be enticed to assist with providing a customised crossover with appropriate performance to interested parties. Pm me for details.
Step 1, 2 and 6
Surprisingly drivers to deteriorate with age,particularly the compression driver diaphram. Have it check by an authorised JBL agent/reconer.
There in an improve driver/diaphragm used in the 4344...the 2425J and there is rare aluminium versions of the diaphram seen on Ebay.
While is had previously built a cloned 4343 its on on sight for direct comparison with updated driver. The 2425J is a superior a driver and the aluminium variant of the diaphragm sort after.
Many have trouble taming the horn in the 4343, I think this is one of the biggest issues with the 4343. The solution is a mix of driver, crossover upgrade and careful setup.
I have used both the 2231A and the 2231H and 2235H. There are differences in power handling and subtle differences in performance. The 2121 and the 2122H are different beasts. I have not A/B'd them so I can't comment. The 2122H does however require a different passive crossover.
We will discuss this in more detail later and perhaps other members can post there experiences with driver updates.
Summary
As mentioned in an earlier post it is important to view the loudspeaker as a system. That is the sum of all the parts of the system come together to create the desired level of performance.
In order to obtain the maximum potential from the loudspeaker we must therefore look critically at each part of the system and decide what updates are required and "how" to implement those updates.
From our investigations we have identified the 4343 system in its raw state is far from capable of producing the maximum potential of its performance. Care needs to be taken when introducing ancilary equipment like active crossovers or graphic equalisers, as they could well be hindering rather than providing a net gain to attaining the maximum potential performance from the system.
The purpose of this post was to give some degree of indication on the net effect of these updates.
Ian
p.s. for the sake of new members who are starting to discover this site, it would help if those of you who have been around for a while not spoil it for us with comments like, "we've discussed this so many times before." it's dissappointing when a thread is prematurely ended...it's all new to me.[/QUOTE]
I agree that, though some things seem obvious or have been discussed to where we think it's "common knowledge", we should try to make these "4343 to 4344 Upgrades" postings as thorough as possible.
I, for one, plan on printing out the succinct pages for a file on this subject...for studying later!
Thanks again, Ian and others, for getting this thread going.
Tom
Tom,
I think that has been rectified.
Ian
Ian: Took a crack at cutting one of my 4344 baffles - 1" P.B. with the mid-base box out of 3/4" P.B. The component layout is similar to the design you posted, with drivers in vertical alignment and non-equadistant to any of the cabinet walls. I moved the ducts down a bit to allow access to the upper internal area for installation of the mid range driver thru the woofer cutout. The other one will be a mirror image of this one. Before I cut the next one - your comments please. Duct tube length is still evading me. Combed thru many many posts and am finding nuttin.
http://audioheritage.org/vbulletin/i...lies/smile.gif
Looks good Rick
The main thing is to make sure everything fill fit together.
ie the drivers, dog box etc will clear any internal aspects on the main enclosure.
Remember there is a brace for the horn driver.
If you plan to make te front baffle permanent why not use the side wall as the enclosure wall for the Dog box!
Ian
BRACE FOR THE HORN DRIVER ????? What brace ?? I was not aware of this. Is it something like that used to support the weight of the 2440 in the 4350 ?? Or is it a cradle that holds the end of the motor like that used in the 4331/4333 ???Quote:
Originally Posted by Ian Mackenzie
I had planned to use two 1 1/2" x 2 1/2" braces, front to back on each side panel. Moving the dog box full right, with it's own side panel, will take the place of the two side braces on one side of each cabinet. After assembling the cabinet I'll go in thru the mid-base cutout and screw the dog box wall to the cabinet side (glue between the two).Quote:
If you plan to make te front baffle permanent why not use the side wall as the enclosure wall for the Dog box!
Ian
Thanks for chiming in. Rick
OkayQuote:
Originally Posted by riessen
Ian
Ian: Tell me about this brace that supports the mid driver. Does it attach to the driver? Is it a cradle to support weight?? I didn't see anything in your drawings. There isn't anything in the 4343's. Was this new to the 4344?
The duct length on the stock 4343s is 8 1/4" for each tube.Quote:
Originally Posted by riessen
I think your work is great! You've come up with a subtle, but definite improvement.
If it were me, though, I think I'd place the 2405 slot directly above the 2420... making a slightly taller cabinet. I like the high end to be up to head level when ever possible.
Great work!
Tom
Hi Tom: Thanx much for your comments. I agree with you on having the 2405 on top and I struggled with the idea and decided not to do it. I have in the past, built tall towers for the express purpose of getting the components up off the floor and projecting into the listening area better. Since I'm calling these 4344's I'm gunna make them look exactly like those built by our buddy James. One exception - since they're never going to be hung or layed on their side, I'm going to mount them on a base and I'm thinking of angling the base so that they tilt back 3-5 degrees. For my intended listening area this should help to better disperse the highs. We'll see. Regards - RickQuote:
Originally Posted by Tom Loizeaux
With the slot on top the dilema is its the narrow vertical polar pattern.
With the slots on the side/outer the action of the crossover polar geomtry is to angle the 8K frequencies and above towards the listening in the middle.
Ian
More experiments.....
Been listening to the stock JBL 5325 crossover today with 4345 cards that just arrived from Santa Rosa CA....thankyou SpeakerDave.:applaud:
Well its been very interesting.
The good news is it's very clean sounding.
The bad news is the 5235 crossover makes every recording sound the same .......:blink: .
A . By this I am referring to the presentation......there is a very strong sense of presence in the midrange, lots of drive.
If your JBLs sound in your face then this is why.....and ultimately fatiguing.:blink:
I think this is another long held characterisation and a false one at that of JBL's in particular the 4343 that is going to be sorted out in this project.
Basically the speakers are a hi end system and it these sort of issues that ear mark hifi from hi end.
B. I compared it to my own crossover and it by comparison sounds perhaps reserved, not in your face. Once I played different stuff the skill of the recording engineer becomes obvious. The music has soul and natural energy.
Removing the active crossover gives the same result as B with some loss of bass detail.
I will attempt the null dc offsets the discrete opamps and bypass the coupling capacitors (B) and see what happens.
I decided to completely bypass (short out) the audio coupling capacitors in a key area just to see what might happen.......
Well let me say its going to stay that way......
I will refer to this as the Earl revision to the design.
The very fine detail and nuance at frequency extremes has opened up while the mids now a sheer clarity that is difficult to describe. Individual tracks appear to take longer to play while at the same time I now feel compelled to focus on the characteristics of specific instruments.
This perhaps is a sign of one being at ease and accepting the sound as correct.... I think so.
I now propose to charge couple the polystyrene capacitors in the actual crossover filters. This will be referred to as the Giskard revision to the design.
What amazes me is that one easily can pick and hear all these refinements up on a 20+ year old loudspeaker design.
Ian
I've always set up my 4333s & 4343s with the slots on the inside, feeling that having a direct line-of-sight to the 2405 slot is better then having some of the slant plate fins in the way. Am I mistaken?Quote:
Originally Posted by Ian Mackenzie
Tom
Each to his own Tom and I would normally agree "if" all the drivers are in the same vertical plane...but not in this instance.
This my graphic below...I'm not much of an artist but there we are.
In the region of the crossover point both the horn and slot overlap and there will be a polar tilt in the direction of the arrow...its that simple. hence I prefer the slot on the outside....I recall the 4344 manual says a much somewhere.
If you put the slot above the horn some of the highs will be pointed at your ceiling!
Ian
After evaluating the 5235 Crossover and the earlier comparisons Ed did b/n full passive an the Ashly active crossovers I am convinced active crossovers can be the route of all Evil in attaining hi end sound quality.Quote:
Originally Posted by Ian Mackenzie
The driver upgraded 4344 is quite capable of hi end sound reproduction if
only given a chance.
Sure, nice passive crossover parts refine and improve transparency but the effect of the Pro PA active crossover cannot be undone..ever....:blink:
My tests and modifications which I am yet to finalise on my own class A
active crossover confirm the level of subjective sound quality the 4344 can
provide.
Done right, an active crossover can provided pin sharp bass transients and
mid range clarity unattainable with a full passive crossover.
Done wrong and its all a pointless exercise...unless of course you prefer listening to Mid Fi.
Yes this does sound like a rant and maybe some of you already appreciate the above. I just find it very annoying that JBL never put out a better unit for these vintage monitors......its not as though they were'nt selling in Japan.:banghead:
Ian
Yep...Quote:
Originally Posted by Ian Mackenzie
Ian, if I hear you correctly Pro PA components may not be the best choice for someone looking to wring the last bit of musical enjoyment out of their Hi End home system. Is this because:
1) For the most part, the intended use of Pro PA quality components is different than the indended use of Hi End components. Pro PA needs to reproduce music usually at sound levels that would be unacceptably loud for most home environments. At these louder sound levels, the sound engineer is would be concerned more with accuracy, lack of distortion, room acoustics, feedback, etc. than looking for the nuances and delicacies within the music. I think both the sound engineer and the audiophile both would be looking to minimize hum but a noise level that what would be acceptable to the sound engineer would not be for the audiophile.
2) Certain of the goals of Pro PA components are achieved at the expense of the some of the goals of Hi End components.
Did JBL ever produce a Hi-End audiophile type active crossover, say for the Synthesis or K2 series.
1.Not really, the JBL BX 63 was aimed at the home user and was designed as such, so was the now defunked DX1. What's in the 5235 is ancient but well executed, the chips used in it were the order of the day however have been since outlawed from consumer CD players and pre amps because they sound bad compared to other more recently developed options.Quote:
Originally Posted by porschedpm
2. I don't know........
If the truth be known I think they would be somewhat frustrated but what's done is done and water under the bridge.
The DX-1 is considered to be a very good example of how to do a proper bi-amp network. JBL still uses the DX-1 for R&D. There is plenty of information about it here on the forum. The JBL M9500 and the JBL XPL200A with their specific DX-1 crossover cards are very good examples of properly bi-amped systems.Quote:
Originally Posted by porschedpm
Ian, Lancer and other Electronic Gurus contributing to this thread - I've read a lot on the forum about custom x-overs but have seen NONE in person. JBL put everything in a neat metal box and it just screwed into the cabinet interior. All of you guys that are building custom x-overs leave me wondering what the end product looks like, how big it is and how/where they are mounted and how much room one should allow in the cabinet to mount a custom x-over. On the forum I have seen all kinds of pics of different x-overs - hugh toroidal coils, jumbo caps, circuit boards with IC's on them, etc. Does anyone have a picture that shows the end product, of a custom built x-over project, for a 4343, 4344,4350 type system - Thanx in advance Rick http://audioheritage.org/vbulletin/i...s/banghead.gif
Rick,
The general idea is to buy the parts build the crossover first.
However if space is a premuim the passive crossover can be build on layers.
You can assume an electronic crossover will occupy 1-2 19 inch rack unit.
Ian
If the WAF is an issue hide everything in wifey's pantry..that's what Bo does.
Ian
Then I was looking at the project ass backwards. I figured the x-overs were the last thing to worry about.Quote:
Originally Posted by Ian Mackenzie
I have seen, I assume x-overs, with stacked boards so this makes sense.Quote:
However if space is a premuim the passive crossover can be build on layers.
1-2 rack units is quantatative so now I have a picture of necessary volume.Quote:
You can assume an electronic crossover will occupy 1-2 19 inch rack unit.
This whole idea is new to me - can't blame me for wondering. If this was a private forum all the "newbies on certain subjects" would not be cluttering up your thread with stupid questions (stupid to some I suspect).
As always, thanx for your answers.
Ian:
Earlier in this thread there is a pic of a mounting board that is the entire height and width of a 4343 cabinet. On it are mounted tons of coils and other caps and gadgets. Obviously it's the cross over for this monitor. So.....As a new guy on this subject - on the outside looking in - is this a typical custom x-over in size and complexity - or - is this something exotic and not what you would call a run of the mill custom x-over. This baby obviously takes up some space.
Regards - Rick http://audioheritage.org/vbulletin/i...ilies/wink.gif
Rick,
That was an exotic approach to contruction and not absolutely necessary.
You need to decide on the drivers, then the crossover and so on.
The active crossover is an anciliary device best placed near your pre amplifier and power amps.
Ian
Hi, Rick.
Assuming Ian doesn't mind me jumpin' in, here's the deal as I see it:
1) Generally speaking, an improved passive crossover can be constructed in the same space that JBL's original occupied. That would include adding bypass capacitors and aircore inductors where appropriate, as JBL did not pay much attention to space conservation in layout of early designs.
2) Further upgrading to a biased (charged-coupled) version of a standard passive crossover requires twice as many capacitors, and those capacitors are also larger than the originals. Typically, this can be accomplished in less than twice the space of the original. Stacking components and boards can reduce the footprint, but it requires knowledge and experience to get it right.
3) There are tradeoffs involved in passive crossover design and component selection. We have all seen the result of a "no compromises" approach in B&KMan's project. I believe anyone with experience building passive crossovers would characterize the effort as interesting, intriguing, even, but patently "excessive." We have yet to hear even from Jean himself whether the expense was warranted.
4) The crossovers you see here with transistors and IC's on them are "active" crossovers, a different approach in which the filtering is accomplished before the amplifiers rather than after. Being interposed between the source and amplifier, they're typically enclosed and mounted in an equipment rack rather than at or in the speaker cabinet like the passive type, which is connected between the amplifier and the individual drivers.
5) Either approach can be employed to accomplish the task, and sometimes it's a combination of both. Which is better is, well, ummm, "debatable" in nearly every instance.... :p
Am glad to hear that the massive array in the pic was on the exotic side of the arena. As a beginner that approach is somewhere in the future for me I would guess.Quote:
Originally Posted by Ian Mackenzie
Driver compliment for my 4344's will hopefully be 2235H's (have two) 2122H's (am researching cone kit availability now), 2425 or 2420/275ND mids (have the horns and lenses) and 2405 (have two). That leaves the x-overs !!! Giskard offered one of his charge coupled systems some time ago and that approach looks to be the best. Will have to leave the physical configuration to him. I'm sure that there will be enough room to accomodate them. Passive/internal with this system is my intent. I have used the JBL 5234's, SAE 4000 and others with my 4350's and have some experience with the active approach (not as extensive as many of you guys out there) but a start non the less.
Thanx for taking the time to reply. Rick
I guess I could send you a picture when I'm done building yours...Quote:
Originally Posted by riessen
Ah Lancer - you are still out there. On the subject of the x-overs we discussed for my JBL-NOT 4351 project - I need to respond to your request for the 3107 bolt pattern and this post has just remined me of that - will get it shortly. I was unable to PM you so tried regular email. Has your email address changed??? RickQuote:
Originally Posted by Lancer
I just answered your emails briefly. I'll look at your emails more closely tomorrow night and answer them more fully.
Thanks Zilchster,
Perhaps Rick can be guided by one of a experienced crossover builders...Ummm.
Please note, If you decide to make a full passive network, this will cost at least 50% more due to the large capacitors for the woofer and midrange filter. This will also add to the physical size of the network.
What I am proposing is a neato active solution for the 4344 project with passive charge coupled crossover for the mid- horn, horn-uhf transitions. IMHO and based on my recent experiements this will give very impressive results without breaking the bank.
The crossover is the heart of any loudspeaker and the results at the end of the day are a careful balance of design, implementation and cost.
Ian
Quote:
Originally Posted by Lancer
Agreed,
Ian
Rick,
How are those boxes going?
Ian
Hi IanQuote:
Originally Posted by Ian Mackenzie
Have one baffle complete with mid-base box mounted and all holes cut. Need more 1" P.B. and have it ordered. In 10-14 days I should have a prototype cabinet done and ready for veneer. Here's a revised dwg. I moved the rear panel recessed area down towards the center. Plan "A" left a real tight clearance between the mid driver and the cabinet back, with the recessed area at the top of the cabinet.
The recessed area is 15" high, 23" wide and 3" deep. This should be enough room to mount x-over components/boards. I'll bounce this off Lancer before I cut any wood to final dimensions.
My best to you as always - Rick
I really don't have the choice of not going full passive on the networks for my 4344 project. The only room I have in the house that has electronics to support a bi-amped/active x-over system is my family room (my turf) and that room is home to my 4350's currently and eventually the 4351's. Going full passive on the 4344's will allow me to put them in any room without needing the extra space for support electronics. To this date the WAF factor has never been an issue. Moving a big full blown system into the living room (her turf) could very well knock a hole in the dike!! RickQuote:
Originally Posted by Ian Mackenzie
Ah Ha...now I see sez I...the waf factor....
Ian
While deemed the obvious we should also do a section on setup and placement.
There is some confusion about the slot being on the ineer and outer edge?
I was having a good listen last nigh before going out on the turps (Saturday night) and it is crucial to this style of monitor that they be palced correctly to ensure not only good imaging, but that the system sounds balanced.
The latter issue is that if toed in too much, you loose the imaging in the extreme highs and the horns can become too prominant.
Ed,
Have you had an opportunity to update the MS Word dcoument yet.
Also, I have requested Unwound (aka Edgewound ~Ken) prepare some posts on driver maintenance, perhaps Techbot will also offer some information of a techincal nature as this is the first topic on the agenda.
If possible I would like to see this posted in the design forum in this month ((September) and we can then rollover the other topic progressively.
Ian
Rick,
Have you thought of installing a couple of plate amps on the rear and bi amping
(or just bolting a stero power amp to the rear......given the cost of power amps (Parts Express) I image the full passive would be perhaps more so.
The active crossover an be anything ...a small black box....
Only one mains cable and one signal cable and your on cloud Nine.
So much more for so much less (done right of course..I would help you with that!)
I revisited this as I am so pleased with the most recent advances I have made in bi amping that passive mode now seems far less attractive.
Ian
After thinking about Ian's mention of correct slot tweeter placement, I pulled the grille frames off my 4343s and noticed that the nameplate is positioned directly over the upper half of the 2405s! These aluminum plates span the width of the grille frame and are positioned to completely block the upper half of the slots vertical horn! How could this meet JBL's approval?
I think I'm going to have to remove these nameplates...at least until I'm convinced that this was either intentional...or that it really doesn't matter!
But really, why do we worry about toe-in or tweeter height relative to listening postion when the 2405s are partially blocked?
How could JBL allow this? I'm puzzled.
Tom
"But really, why do we worry about toe-in or tweeter height relative to listening postion when there are largly blocked?
How could JBL allow this? I'm puzzled."
That's odd to say the least that they are blocked by the name plate?!! I run my clones naked with no grills and toe in and height do indeed make a difference. Why they are blocked??? Any doubt dump the grills and see for yourself.
Rob:)
Ha,
A lot of engineering effort went into the position of those name plates...LOL.
I doubt if many people use them with the grills on.
Tom this is an interesting issue....have you tried with the grills on/off to verify any change ?
Ian
Move the nameplate to the opposite side.
Quote:
Originally Posted by Ian Mackenzie
:beach:
mmmmmmmmmmm... HEY © pict !!!
well, directly on my beach, I catch a strange vibration on other side of sea...
and I read a couple of point of view on botton Lf case and positionning driver and....
OH OH where is come ...
a 4348 model!!!
I looking the level of doors sky for past of 4343 level to 4344 level and I feel a few reserve...
the alnico driver is better than ferrite driver but the new diaghram expose better upgrade performance. so my opignion is the old driver alnico with new diaghram is expose better flat response and low distorstion due to fatigue material.
the cancellation of back switch (single or bi-amp) is not exposed on upgrade list but it is a top of the line upgrade in regards of the price and influence of LF response!!!
the re-design cabinet on 4343 is not easy question... and my eyes is wait the solution but the 4348 expose the same position of event port !!! so if you rebuilt completely the front and feel to upgrade driver for recent technology: the 4348 model is looking better no ???
In fact, the new drivers is appear realy improvement... and the introduction of Ultra-Uhf is very interesting...
for the front panel, the hard-wood plywood is really improvement of the MDF...
:cheers:
look my avatar pict or go to "4343 crossover modification" thread. for full pict interaction.Quote:
Originally Posted by riessen
:beach:
Attached below is the latest revision of the framework for this project. We've added sections on basic setup and speaker placement and a section on improvements that can be made to the cabinets. We've also added an open ended section at the end for members to describe their more exotic modifications to their 4343 based monitors' drivers, cabinets, crossovers, etc.
Upgrade Modifications to the JBL 4343/4343B Studio Monitors:
This thread will describe several different upgrades available to owners of 4343 and 4343B Studio Monitors. Although we are focusing primarily on upgrades to the 4343 series monitors, owners of other Studio Monitors, 4344, 4350, 4333, etc, will find that many of these upgrades could apply to them also. The upgrades will be broken down into various upgrades starting with relatively simple upgrades up through a full upgrade of the drivers and crossovers. The basic framework here is to offer modifications that improve the performance of the 4343/4343B monitors while preserving their vintage appearance. A requirement here is that the speakers continue to look original. Therefore we will avoid any modifications to the cabinets or grilles. In addition, it is not within the scope of this thread to discuss how to restore the cabinet or grills. There are numerous other threads on the LH Forum that cover these aspects in great detail.
Setup and placement
1. Amplifier power recommendations
2. Connections
3. Room acoustics and monitor placement
4. Slot Tweeter placement- inner vs outer
5. Removing the top baffle
6. Measuring performance.
Upgrade 1 – System Maintenance:
1. Clean L-Pads, replace if necessary
2. Clean/improve terminations.
3. Testing condition of drivers and crossovers
4. Recones, refoams and new diaphragms.
Upgrade 2 – Upgrade 4343 drivers to 4343B spec.
1. Replace 2231A with 2231H
2. Replace 2121 with 2121H
Upgrade 3 – Bypassing the bi-amp switch.
Upgrade 4 – Upgrade the stock crossovers.
1. Replacing capacitors.
2. Bypass Capacitors
3. Charge coupling
4. Upgrade crossover to 3145 spec.
Upgrade 5 – Discussion on Bi-amping.
1. Pros and cons.
2. Active crossovers available on the market
Upgrade 6 – Upgrade drivers to 4344 spec.
1. Replace or recone LF drivers to 2235H
2. Replace or recone MF drivers to 2122H
3. Replace or rediaphragm HF compression driver to 2425J.
Upgrade 7 – Converting to Hi End Crossovers.
1. Internal vs External placement
2. Passive
3. Active
Upgrade 8 – Cabinet Upgrades
1. Improve internal bracing.
2. Modifying the top 4343 baffle
3. Modifying the bottom 4343 baffle
4. Cabinet and grille repairs
Upgrade 9 – Discussion on modern drivers.
1. Modern driver choices available today
2. Use of a subwoofer.
Upgrade 10 – Other Upgrades.
1. External Horns
2. 4345
3. Other upgrades
Great,
Well that should keep us busy for a while.:)
Ian
hello porschedpm,
I attentively looked your list and after my great adventure on my stock 4343
(see 4343 crossover modifications Thread http://www.audioheritage.org/vbullet...ead.php?t=1388 ) , I leaves to be humbly made certain modifications with your list of step of levelling.
just before:
By definition a levelling exposes an improvement of design (form or
parts).
The setting in phase in the part and the various aspects which are
attached to it are in fact an optimization... cleaning and the
checking not being a levelling either...
Therefore,
With regard to the levelling:
=======================================
1 --- it is clear for me that the first thing is to put of better
connectors and to cancel the switch Bi-amp. Undoubtedly simplest and one of best levelling to make.
=======================================
2 --- The tiredness of the diaghram requires a replacement most of
the time. After 30 years, several diaghram owed beings installed on the 4343. To supervise, most of the time the former owners put copies of diaghram rather than
originals...
And because with share the UHF no diaghram of origin is
available: The choice of replacement will be according to the ambition of the
levelling.
the basic levelling will be:
-- le 2231 by diaghram 2235
-- le 2121 by diaghram 2122H
-- le 2420 by diaghram 2421 or 2425J (according to the preferences titanium or aluminium)
-- le 2405 by same diaghram 2405
Obviously if you plan to change the drivers, this list is useless.
=======================================
3 --- Levelling of the Condensers and resistances. The ordinary quality of resistances and the old age of the
electrolytique capacitors you ensure a good loss which is reflected on
all the drivers. A change by audio of Solen type or similar metalized polypropylenes will enable
you to feel a good improvement. To try to put the films and foils metallized or better on the high frequencies and to circumvent the large values of low by still of the films and foil. Another improvement is to put the networks outside the cabinet to expose it to less of vibrations. My experiment is that the 3145 diagram is not very powerful with the diagram sof origin thus if you made not the levelling, avoid remaking the network...
Thus your improvements will be maximized... and you will have
perhaps even exceeded in certain aspects the 4344 (since the diagrams
are of more recent technology). your 4343 will sound to the maximum of their prowess without you to cut the throat of the account of bank.
=======================================
4 --- If the heart feel to modify your 4343 more why go worm the
4344 whereas very recently the exercise at summer made by JBL even by
the 4348!!! Time and the money which you will spend to optimize design who also
goes back him to 30 Years to me seems finally profitable compared to a
levelling to 4348...
Moreover the drivers advantage of old is the
alnico five... To replace by ferrite seems to me a retreat... The specialized reviews
of Europe and Asia regard the alnico as superior with ferrites.
to replace it
--- 2231 by 1500FE
--- 2121 by 2251J
to add Ultra Tweeter JBL 045 TI and a network to adjust with the
sensitivity and here....
More still???
Remade a Russian top of face in plywood and install in the place of HF
and UHF a JBL 435A and integrate a JBL 045 TI and you have almost
that one 4348...
build the network in cd. now Charges with reels and condensers
with the height of your madness and here is a solid levelling and will
start again your 4343 for another quarter century....
(BTW I have nothing big surprise if JBL sale this upgrade for studio Owner…. )
N.B.
The question of Bi-amplification, of subwoofer or another addition seems me to raise more of the question of the overall system that of a levelling...
I hope that my point of view will be useful to all in this quest of music...
Jean
Thanks Jean,
The above agenda is bullet points for clarity.
All your points will be thoroughly discussed at each stage.
Ian
Hi, Jean. Thank you for your good observations. I also found it very tempting to want to jump ahead and describe what I feel the ultimate modern iteration of the 4343 monitor would be. However, as Ian pointed out to me over and over again, we want to appeal to as many 43XX owners as possible and so we need to break the upgrades (levellings as you call them) into smaller sections because not everyone will want to perform all the upgrades. Some owners may be satisfied with performing only one or two upgrades. On the other end of the spectrum, others will want to essentially build the ultimate 43xx derivative based on all modern drivers and modern crossover technology. We wanted to structure it so 43xx owners could pick and chose the upgrades they feel comfortable performing and also layout the structure so that each progressive upgrade is a little more extensive than earlier upgrade. We also decided early on that there are certain controversies that we will want to avoid. One of these is what brand internal or external wire is the best to use. Another is the Alnico vs Ferrite debate. These are both subjects for which many differing opinions abound and to get into these debates here can quickly confuse the purpose of the project and polarize the members. I know that you have a lot of experience already performing upgrades to these monitors and crossovers and I look forward to your continuiing contributions to the project.
Ed
Quote:
Originally Posted by porschedpm
Boujour with you also,
(sorry fo bad traduction of upgrade = leveling (mise à niveau => in french)
I account of the objectives and the stages goes well to present, however the choice even of unquestionable upgrade can be discustable
in discussion in depth. I believe that your company is extremely creditable and this is why I have to decide to expose you my opignion on the step and not on final solutions from the beginning.
My intervention humbly aimed at clarifying certain aspect slipping ex: the multiple change of drivers to wire of the upgrades can in end line
expensive and investisement to represent frustration and bad being...
so maybe the best title is " procedure for upgrade your 4343" (not necesary at 4344) or
" any you want about improvement your 4343 !!!"
Lastly, however, I say yes at your project and I will try as much as I could provide my small contribution.
Jean,
Are you able to post a picture of the biamp switch?
Thanks
Ian