DIY 2235h, 2206h, 2446J Be or TAD 4001 and 2405H Build Thread

[Champster]

I thought I'd start a thread on my attempt to build a reference system that is one step more advanced than the JBL Synthesis K2 S9900. Although I have never heard the S9900, I love the design concept and am pretty sure it would rival, or exceed, many high end, audiophile systems. I am thrilled to get your comments (positive or negative) on my project. I realize that in any project like this, there are varying opinions on build theory and I won't bristle at your thoughts.

To start, a little background on me and my design goal. I am a life-long audiophile. This system is exclusively for my home listening room which is 19 x 15 x 9. It is a dedicated listening room and I have it set up as a live end (behind speakers) /dead end (behind listening position) and listen in the longer length of the room.

I have built, and purchased, many speakers in my 30+ year devotion to high end audio. Some of these, kind-of in order, include Infinity Beta Clone's, Wilson Audio WATT/PUPPY and WAMM clones, JBL L300, Altec Model 14's & 19's, Martin Logan (CLS and others), Entec, Muse and Velodyne subs, to name just a few. My latest love is dynamic, dipole speakers from Linkwitz Labs. I have built and owned the Orion and now the LX521. Check them out here. (http://www.linkwitzlab.com/index.html) I consider the LX521 the most pure speaker I've ever heard and that includes some of the most celebrated audiophile speakers of all time (Soundlab, IRS, WAMM, B&W Matrix 800). So you ask, why am I building another speaker system? Fair question. The answer is that I love designing and building things and I want to build something that tests how close I can come to my LX521's as my Reference system. In the past, the one shortcoming in my efforts was the ability to analyze the output in a highly detailed, electronic way. I've always just used my, and a few buddies, ears. Well, we all know how accurate that can be.... Now with the creation of affordable DSP, the amateur speaker builder can analyze, evaluate and make changes much easier, cheaper and faster than ever before. So I'm awaiting delivery of my new miniDSP 4x10hd (http://www.minidsp.com/products/minidsp-in-a-box/minidsp-4x10-hd). In addition, I also have the Behringer RTA (http://www.behringer.com/EN/Products/DEQ2496.aspx) on hand. Luckily, Mr. Linkwitz has approved a DSP setup for the LX521 to replace my existing ASP. So, with that background, I came here to source what I know to be the best drivers available to see what I (with your help) can build.

To start, I'm not a big fan of the square box solutions (like the 4345) that JBL has historically designed. I've just never been able to eliminate cabinet resonances from big boxes. From a design perspective, I'm much more interested in the cabinets from the JBL Synthesis line. I'm thinking curves with lots of bracing using Sono construction tubing to make a D shaped cabinet. As the title of this thread discloses, I've sourced pristine pairs of the following: 15" (2235h) subwoofer; 12" (2206h) woofer; 2" Compression Driver (2446j) with a 2380 horn and (2405h) tweeter. I'm estimating the crossover points (all LR 24db/oct) at 100, 900, 8000, but those are subject to change with the miniDSP. I'm thinking 5 cf vented (tuned to 30 hz) cabinet for the 2235 and 1 cf sealed (.57 Qtc) for the 2206. I have read that mounting the woofer and midrange as close as possible is very important to achieve a seamless blend between the dynamic woofer and compression driver midrange and it helps to avoid the honking horn effect. I prefer to have an image that is slightly above my seated ear height (38") and plan for the center point of the horn to be about 45" high.

At this point, those are my design thoughts. I'm really going to give this the old college try and compete with the a great reference system that was designed by one of the most important contributors of speaker design in my lifetime. I'd love your thoughts, help and encouragement!

Thanks,
Paul

[JuniorJBL]

I am not sure that this will be very helpful but when I was looking to go down this path but with different drivers, I was told I should do a sub/sat system instead of a 4 way. You may also want to put Be dia's in your 2446's and run them all the way out without a band-pass (remove the low pass on the top of the band-pass).

You should also visit the REW forum http://www.hometheatershack.com/forums/rew-forum/ for a primer on speaker measurement and what can be done with it. I know GT recommends REW as a good starting point for doing speaker measurement.

Member 4313B did a "1200 Array" http://www.audioheritage.org/vbulletin/showthread.php?33151-DIY-1200-Array&highlight=1200+array which used your 2206H and produced very good results.I would look into that as your primary means of attack. Use the 2235H's as subs.

I am by no means the end all voice for JBL s maybe others will chime in and correct me where I am wrong. :D

[Champster]

I am not sure that this will be very helpful but when I was looking to go down this path but with different drivers, I was told I should do a sub/sat system instead of a 4 way. You may also want to put Be dia's in your 2446's and run them all the way out without a band-pass (remove the low pass on the top of the band-pass).

You should also visit the REW forum http://www.hometheatershack.com/forums/rew-forum/ for a primer on speaker measurement and what can be done with it. I know GT recommends REW as a good starting point for doing speaker measurement.

Member 4313B did a "1200 Array" http://www.audioheritage.org/vbulletin/showthread.php?33151-DIY-1200-Array&highlight=1200+array which used your 2206H and produced very good results.I would look into that as your primary means of attack. Use the 2235H's as subs.

I am by no means the end all voice for JBL s maybe others will chime in and correct me where I am wrong. :D

I don't know what the advantage would be to run a sub/sat system? I'm planning on using the 2235 as a sub up to 80-100 hz.

REW looks like a great tool. I have it downloaded. HTS is another great forum.

I hadn't seen this thread. Looks like a lot of good info. Thanks!

Thanks Paul

[JuniorJBL]

For most subwoofers to perform well they should be below 80hz IMHO.

I typically run mine at 55-60hz with an 18db slope. YMMV

:)


I don't know what the advantage would be to run a sub/sat system? I'm planning on using the 2235 as a sub up to 80-100 hz.

REW looks like a great tool. I have it downloaded. HTS is another great forum.

I hadn't seen this thread. Looks like a lot of good info. Thanks!

Thanks Paul

[Champster]

No argument here. I totally agree with your sub crossover comment of keeping it well below 100 but I see a lot of people (even JBL) using the 2235 in 2 way systems. I assumed that meant it was very well behaved above the more prudent high pass cutoff of most subs. What tuning would you recommend for the tuning freq of the 2235? This is from 4313b's post. "I guess I'll find out if the "single fifteen in a small box going straight to the vertically oriented horn" ends up being the best implementation. The large single fifteen boxes that preceeded these dual fifteen boxes were also "28 Hz" boxes. The small single fifteen boxes are "35 Hz" boxes, still reasonably respectable for a wide variety of material. All the Everest II boxes are "31.5 Hz" boxes."

[JuniorJBL]

The 2206 will go to 50 hz without any help and do it well. So I would shoot for the 28hz-30hz box but that is my preference for subs. cross them somewhere between 50 and 70 hz. 4313B said the 2206 had fantastic dynamics so I would not worry to much about it. :)

[Champster]

The 2206 will go to 50 hz without any help and do it well. So I would shoot for the 28hz-30hz box but that is my preference for subs. cross them somewhere between 50 and 70 hz. 4313B said the 2206 had fantastic dynamics so I would not worry to much about it. :)

In order to get the 2206 to go that low, I'll need to change to a vented enclosure or add eq in the DSP with the sealed enclosure. I like this suggestion but was reluctant to use a vented enclosure for the 2206. What experience can you point to where a 2206 is used like this?

[Lee in Montreal]

Hi Champster

If your plan had included an 18" 2245 instead of the 2235, then I would have said you have the right recipe for fun. Nothing to change. But with a single 2235 per cabinet, you will very soon find the limitations of that driver. If you go with 2235 woofers, may I recommand you fit two units per side. That's because they are not very efficient and you can't feed them with much power. While the 2245 is an "authoritative beast", the 2235 is its weaker baby brother... :D

[grey]

To further elaborate and offer my understanding of Lee's post.
The 2235 is the limiting factor as normally determined by the sensitivity of lowest freq. driver in a system.
Not that it can't be done and work ok. It will end up as a targeted flat 93dB.

At 1w/1m:
2235 = 93dB
2206 = 95dB
C.D. and ring radiator > 100dB

2245 = 95dB

Personally I would go with the 2245 as well if building from scratch. I've not seen much if any difference in cost. It will need a larger cabinet of course.

[Champster]

To further elaborate and offer my understanding of Lee's post.
The 2235 is the limiting factor as normally determined by the sensitivity of lowest freq. driver in a system.
Not that it can't be done and work ok. It will end up as a targeted flat 93dB.

At 1w/1m:
2235 = 93dB
2206 = 95dB
C.D. and ring radiator > 100dB

2245 = 95dB

Personally I would go with the 2245 as well if building from scratch. I've not seen much if any difference in cost. It will need a larger cabinet of course.

Lee and Grey- You guys are great! Thank you for that guidance. Since I am in the build from scratch mode, that will be a relatively painless swap.

I'm on the prowl for a pristine pair of 2245's...

Thanks again,
Paul

[Lee in Montreal]

The 2245 is a great driver. ;-)

Lee

[JuniorJBL]

The 2245 is a great driver. ;-)

Lee

+1 ;)

[grey]

To show the difference, if you opt for brand new cone kits this is the latest price:

C8R2235 $214.00
C8R2245H $276.00

Otherwise I've not seen used, good cond. units vary much.

[Lee in Montreal]

Plenty of cheap 2240 baskets available to recone as a 2245. Look for baskets on your local Kijiji, not on eBay. :D

As for crossing over, 12db/octave LR is fine and will sound natural. ;-)

[christo]

Hi Champster

If your plan had included an 18" 2245 instead of the 2235, then I would have said you have the right recipe for fun. Nothing to change. But with a single 2235 per cabinet, you will very soon find the limitations of that driver. If you go with 2235 woofers, may I recommand you fit two units per side. That's because they are not very efficient and you can't feed them with much power. While the 2245 is an "authoritative beast", the 2235 is its weaker baby brother... :D

I’m with Lee on changing the 2235 to 2245. I just finished a 4344 set with 2235/2123/TD-2002/2405 and if I could do it over again I would just do a 3-way with 2245/2123/TD-2002.

[christo]

I thought I'd start a thread on my attempt to build a reference system that is one step more advanced than the JBL Synthesis K2 S9900. Although I have never heard the S9900, I love the design concept and am pretty sure it would rival, or exceed, many high end, audiophile systems. I am thrilled to get your comments (positive or negative) on my project. I realize that in any project like this, there are varying opinions on build theory and I won't bristle at your thoughts.



As for getting vintage JBL’s to sound anywhere near modern JBL speakers you won’t come close. I know as I have them side by side (4344/K2 S9900) and it is no contest. A beryllium compression driver in the 4344 helps with imaging but nowhere near what the 1500AL-1/476Mg combo can do. I have spent hours fiddling with my 4344s and have them sounding as good as they’re going to get, you can’t tell your listening to a horn speaker any more, but they’re no were near the K2s.

[Champster]

Moderator: How do I change the title of this thread. I fix the typo "1446" to "2446" and want to change the 2235h to a 2245h. Maybe this can't be done once the thread is started.

Thank you Cristo (and others) for your confirmation of JuniorJBL point to dedicate the 2235 as a sub and Lee's suggestion to consider swapping out the 2235's in favor of the 2245's. I have now sourced two 2245 frames and will be having Orange County Speaker recone them next week with new, original JBL cone kits.

I am curious Cristo about your comments on the sound quality and would appreciate you expanding your thoughts. I love your approach to focus on great sound quality (not max SPL's) as THE design goal. Unfortunately, the modern drivers in the S9900 are hard to come by, so for the time being, I am left to using the older JBL gear. If I find my results mirror your comments, swapping out the midrange CD is an option down the road.

However, I would appreciate your comments on the following as well.

The approach I am taking is different than the 4344. In the 4344, there is a blatant dis-concern for one of Drew Daniel's very first points on the Horns page in his Daniel's System (http://www.audioheritage.org/html/perspectives/drews-clues/2-horns.html). In this article, one of the required design aspects is to orient the midrange horn and woofer driver physically very close to each other. The 4344 doesn't take this thought as far as it could and perhaps that is one of the reasons the purity of its horn is challenged compared to your S9900. The other reason, is that the 4344 (and others like it) mount all the drivers on a simple, large, flat surface. The new Synthesis cabinetry is very sophisticated in comparison also uses much steeper crossover slopes. There is another issue to discuss. One of my personal pet peeves is the high crossover point on both systems for the woofers. On both the 4344 and the S9900, they run the 15" woofers to a much higher crossover point than I find enjoyable. For example, Daniel's runs his woofers up to 300hz (http://www.audioheritage.org/html/perspectives/drews-clues/2-horns.html), the 4344 up to 340hz (http://www.jbl.com/images/media/4344MKII_OM_EN.pdf) and even the S9900 up to 900hz (http://www.jblsynthesis.com/downloads/products/prod_93_634484024579847476_JBL-K2 speakers_092209.pdf). As JuniorJBL suggested earlier, to limit the large driver to well below 100hz and, in fact, ideally, no more than 50-75hz. To drive this point home, in the case of Mr. Linkwitz's designs, he runs his THOR sub (12" sealed cabinet with EQ) up to 45hz with a 24db slope. I realize, in the case of the S9900, the woofer isn't designed to be a true sub, but nevertheless, it is still a large, heavy cone that does have responsibility to cover the lower registers. It is for this reason, I chose to use the 2106h (12") in between the 15" (now 18") originally. The 2106 versus the 10" of the 4344 allows for nearly full power down to the Subs crossover point. In a DSP system, I can use the 2106 in a sealed cabinet, adding about 5db of EQ to get it to 60-75hz with very good power handling characteristics. This will allow the 2245h to do what it is ideally suited to do.

I'd love all of your comments...

Thanks,
Paul

[christo]

Thank you Cristo (and others) for your confirmation of JuniorJBL point to dedicate the 2235 as a sub and Lee's suggestion to consider swapping out the 2235's in favor of the 2245's. I have now sourced two 2245 frames and will be having Orange County Speaker recone them next week with new, original JBL cone kits.

I am curious Cristo about your comments on the sound quality and would appreciate you expanding your thoughts. I love your approach to focus on great sound quality (not max SPL's) as THE design goal. Unfortunately, the modern drivers in the S9900 are hard to come by, so for the time being, I am left to using the older JBL gear. If I find my results mirror your comments, swapping out the midrange CD is an option down the road.



I have had the pleasure hearing another member’s 4345 (for far too little time) and have spent hundreds of hours with my 4344s and K2s. Each speaker has a very distinctive sound and I and enjoy all three sets. Don’t get me wrong my comments are not meant to criticize the 43xx series. When the 43xx’s are set up correctly are very impressive (killer) and far exceed many of today’s systems.

The more obvious factors with the difficulties of trying to match the performance of modern JBLs with vintage gear, is component engineering. Thirty years have gone by and there have been improvements in driver design, materials used and electronics etc. all of which has been discussed in detail in this forum. In the Array series, K2, and E2 (and others) these advances are very evident with the quality of the sound.

As for your discussion of the cross-over points and different combination of drivers I’ll have to leave that to others who have much more experience in this area as I’m not one of them.

What I can relate to you is my impressions;


The K2s generate a very wide and deep sound stage there’s no need to sit in a sweet spot with the 4344s there is definitely a need to sit in a particular spot.
The micro nuances in the sound that K2s are capable of is extraordinary to the point of being almost three dimensional. Think of the sound of a really good set of headphones but this is occurring in the open air over a large area. The 4344s won’t do micro nuances without a beryllium driver and now where near what the K2s can do.
When listening to the K2s most of the time it is impossible to associate sound with the individual speaker you are totally immersed and surrounded by the sound field. The 43xx are very direct.


When guests hear the K2s these are the typical reactions;


Within 120 seconds their jaw drops and they realize there are hearing something special.
More than one has made the comment this is live!
More than one has made the comment I can’t tell where the sound is coming from, as they look left, right, up, down and behind them.
None are in a particular hurry to leave and one guy was still listening 2 hours later.


Guests don’t react to the 4344s they like the look of them and agree they sound better than most other speakers they have heard but that is about it.

On a personal note I listen to each set for 3 to 4 weeks and then swap (only one set of amps). I thoroughly enjoy the 4344s but without the TD-2002 I would have deemed the project a fail as I would not listen to them (originally I was using a 2426H). When swapping from the 4344s to the K2s you have to let a few days go by to erase the sonic memory of the K2s. If you swap from the K2s to the 4344s and listen to music immediately it basically sucks. But swapping back to the K2s is cool because it’s like the first time you ever heard them and you get to go WOW all over again.

I have added a pair of Array 1500s to augment the K2s bottom end and I’m very happy with the combination, they blend easily together. The Array 1500 also reminds you of just how good a driver the 1500AL-1 is.

If you serious about a reference system beyond a K2 you should consider those two very rare components for sale in the LH Marketplace at the moment.

I would also strongly suggest that you go and have a listen to a K2/E2 system etc. prior to embarking on your project it may influence some decisions. Not that there is anything wrong with your project, you will end up with great sound.


Chris

[Ian Mackenzie]

Not meaning to move the goal posts but have you considered the E145?

Its a very nice driver if you want to consider a low distortion hi sensitivity 2 1/2 way. use the 2245 as a sub and omit the 2206

The ideal behind the Drew Daniels system is deliberate band width limiting with brute force.

Crossing over below 300 hz can invite issues like group delay.

At frequencies below 150 hz you have lots of room modes that have peaks of +- 10-15 db.

If you are not really careful using a sub crossing over in that territory can excite those room modes and its ugly.

How often do we hear loud moaning that I cannot get my subs to integrate with the mains?

Just letting the main driver run its full band pass ie 40 - 800 hz and then use a low pass filter only for the sub below 40 hertz can work if you tweak it enough.

I am looking at something similar with OEM 3rd party drivers...yes I am sinner I know but if you thought JBL distribution was bad in the USA try down under...

So I am stretching the low end response extension of a hi sensitivity low distortion under hung 15 inch woofer as far as possible with what GT calls a banana curve tuning.

The idea is the response goes lower but shelves earlier like at 80 hertz but the room gain adds back some lift of around +5 db below 100 hertz and you can get another 10 hertz extension down to system resonance ie 35 hertz as opposed to 45 hertz.

You can then mess with using the 2245 for what it was made for ie B460 tuning and you have serious 25 hertz capability.

[Mostlydiy]

Interesting project. Youre certainly aiming high constructing a system with "old" drivers to compete with todays top of the line drivers, a 4 way diy network at that. This is not easy, I hope you will be satisfied.

/Mostly

[Champster]

Thank you Mostly. Yes it is a very ambitious effort. I have just sourced a TAD 4001 original Be diaphragms along with the new JBL 2446's with a Ti ribbed diaphragms to A/B after it is assembled.

I like the system pictured in your avatar. Do you have a link you could send me with larger pictures and details of it?

Thanks,
Paul

[Robh3606]

This is the driver line up in my 4 way active mains. I have B380's 2235's with BX-63A up to 80Hz E-145's up to 300Hz to 2123's up to 1.5K to PTH1010's with 435Be's. Works quite well. I wouldn't get all hung up on driver size. It's the capability of the individual drivers over their range that's going to make or break what you are trying to do. I went for speed and impact which is why I use an E-145 as a midbass driver. They also have to play nice with each other.

Rob:)

[Champster]

This is the driver line up in my 4 way active mains. I have B380's 2235's with BX-63A up to 80Hz E-145's up to 300Hz to 2123's up to 1.5K to PTH1010's with 435Be's. Works quite well. I wouldn't get all hung up on driver size. It's the capability of the individual drivers over their range that's going to make or break what you are trying to do. I went for speed and impact which is why I use an E-145 as a midbass driver. They also have to play nice with each other.

Rob:)

Good advice. Thanks!

I thought you were using the speaker in your avatar?

[Mostlydiy]

Thank you Mostly. Yes it is a very ambitious effort. I have just sourced a TAD 4001 original Be diaphragms along with the new JBL 2446's with a Ti ribbed diaphragms to A/B after it is assembled.

I like the system pictured in your avatar. Do you have a link you could send me with larger pictures and details of it?

Thanks,
Paul

Speaking of ambitious projects :)

http://www.minhembio.com/mostlydiy/317875/

/Mostly

[Champster]

Wow, Mostlydiy, that is an ambitious project. Do you still use it as shown in the pictures in the link?

I haven't posted for a while because I've been planning my dedicated listening room addition, but now that I am nearing completion of the planning phase of that, I'll be able to begin building the cabinets for this system.

So, since I've received a ton of very valuable input, here is where we are.

As the title says, I've secured all the drivers and the DSP 4x10Hd, as well as, 2 - ATI 1506 amps.

I have a few additional questions:

1 - Is the 2405 really necessary with the TAD 4001 or JBL 2446 using the Truextent Be diaphragm? Thoughts?

2 - Is the 2206 really going to offer the detailed midrange I'm hoping for? I see almost all of the big 4xxx JBL designs use a 10" midrange. Ideally, I don't want to run the 2245 any higher than 60hz. Thoughts?

3 - I've decided to use the 2245 in a separate 12cf box and have the mains in their own cabinets. Using the DSP, I can easily adjust for time delays between the two. Thoughts?

Thanks,
Paul

[Mostlydiy]

Yes, I still use them with 2482 and 2350 as in the last image in the link.

With a minidsp 4x10 its easy to try different setups. I would try both with and without the 2405. I probably would use it but it might come down to personal preferences. Depending on the horn you are going to use with the 4001 or 2446 I think you might get better dispersion in the higher register using the 2405. (what horn are you going to use? havent seen it anyware but I might have missed it)

I think you have to let the 18" go higher to be able to use a 10". The 12" should work better if you want to cross the low mid at 60. Unfortunately I have no experience with the 2206 so I cant comment on detail.

If you are going to use the lows in separate boxes you might aswell first go with seperate enclosures all the way initially to figure out what setup you like like (http://www.audioheritage.org/vbulletin/showthread.php?34338-2245-active-3-way&highlight=g1+2245) this guy.

Just my 2c

/Mostly

[colofan]

Okay I have both 2245 and 2235 for music unless you are going for the pipe organ the 2245 is better for the bottom but harder to match in the mid-bass. I prefer the 2118 for mid-bass since it is easier to blend with a midrange. Choose your midrange but I prefer the 2404 on the top for wider horn pattern than most of the design until K2.
For music as long as I don't get crazy with the SPL 2235 works great above 30Hz (ported design).

If you want to kick your pants then 2245 or something even crazier in the sub category. There are a lot of subs available that have some tremendous Xmax for sub-sonic performance.

When I was working on a design for a fellow HT system that had 2206 for mid-bass in his words "lacks the punch in the upper ranges and not so great on the mid-range blend" we are still working on it but I think he has a room problem and analog crossover design.

So is this music or HT?

I use the high efficiency in the HT since the explosions and such dynamic level is where it is at.

In the music system it is 2235 with a Dynaudio top end (10 inch mid-bass, 3 inch dome mid-range, 1 inch dome tweeter) , voice coils aligned very wide soundstage. Giving up on the top SPL but for about 99% of the music I play very listenable for the last 10 years.

[Champster]

Yes, I still use them with 2482 and 2350 as in the last image in the link.

With a minidsp 4x10 its easy to try different setups. I would try both with and without the 2405. I probably would use it but it might come down to personal preferences. Depending on the horn you are going to use with the 4001 or 2446 I think you might get better dispersion in the higher register using the 2405. (what horn are you going to use? havent seen it anyware but I might have missed it)

I think you have to let the 18" go higher to be able to use a 10". The 12" should work better if you want to cross the low mid at 60. Unfortunately I have no experience with the 2206 so I cant comment on detail.

If you are going to use the lows in separate boxes you might aswell first go with seperate enclosures all the way initially to figure out what setup you like like (http://www.audioheritage.org/vbulletin/showthread.php?34338-2245-active-3-way&highlight=g1+2245) this guy.

Just my 2c

/Mostly

Great points. I am using the JBL 2386 horn. I know it isn't as wide of dispersion as others, but I have read others suggesting that other JBL horns like the 2380 have a slot to force the wider dispersion that they claim changes the character of the sound. Also a great suggestion to have test boxes to swap drivers in and out to test what works best.




Okay I have both 2245 and 2235 for music unless you are going for the pipe organ the 2245 is better for the bottom but harder to match in the mid-bass. I prefer the 2118 for mid-bass since it is easier to blend with a midrange. Choose your midrange but I prefer the 2404 on the top for wider horn pattern than most of the design until K2.
For music as long as I don't get crazy with the SPL 2235 works great above 30Hz (ported design).

If you want to kick your pants then 2245 or something even crazier in the sub category. There are a lot of subs available that have some tremendous Xmax for sub-sonic performance.

When I was working on a design for a fellow HT system that had 2206 for mid-bass in his words "lacks the punch in the upper ranges and not so great on the mid-range blend" we are still working on it but I think he has a room problem and analog crossover design.

So is this music or HT?

I use the high efficiency in the HT since the explosions and such dynamic level is where it is at.

In the music system it is 2235 with a Dynaudio top end (10 inch mid-bass, 3 inch dome mid-range, 1 inch dome tweeter) , voice coils aligned very wide soundstage. Giving up on the top SPL but for about 99% of the music I play very listenable for the last 10 years.



I have both a pair of 2245s and 2235s, but have really settled on this being a dedicated sub under 70hz so I leaning toward the 2245. Your comments on the 2206 as a midrange are very helpful. As this is for 2 channel listening, I'm really leaning to using the 2123 above the 2206. This would also allow for a higher crossover point to the CD. In reading about the new JBL systems it appears to me that they are much better at blending the midrange with the large woofers and CD than, say, the woofers of yesteryear. So I'm considering using these older drivers in a narrow frequency response with the tradeoff, obviously, requiring additional crossover points and the required blending of the drivers. I'm not sure I can pull that off, but the miniDSP should make it faster and easier than using passive components. My ear is particularly sensitive to hearing midrange though a driver that is clearly too large and slow. I just don't care for using the 2235 for example in the L300 up to 800hz. I'm trying to avoid using drivers in a configuration that requires them to cover too large of range. I'm sure many will disagree with me and that is fine. I'm open to your opinions.

Thanks,
Paul

[JeffW]

Before writing the 2206 off, you might take a look at This Thread (http://www.audioheritage.org/vbulletin/showthread.php?33151-DIY-1200-Array)

[Champster]

Before writing the 2206 off, you might take a look at This Thread (http://www.audioheritage.org/vbulletin/showthread.php?33151-DIY-1200-Array)


Thanks Jeff. That is a very interesting thread and it was helpful in my selection of the 2206, but didn't I read that 4313 replaced that system with another more current model.

I guess as I've been thinking this through, and trying to find some previous design that I must be mimicking, I'm leaning toward a modified Daniel's system using a 2206 instead of the dual (2227) 15's.

[JeffW]

Thanks Jeff. That is a very interesting thread and it was helpful in my selection of the 2206, but didn't I read that 4313 replaced that system with another more current model.



He may have, I can't keep track of his builds, but the point was that some still consider the 2206 to be a pretty decent midbass driver. Another thing to consider is the availability of "more current" drivers to the average consumer. There was a time when normal guys were buying drivers like 1200FEs, not sure that's an option anymore.

[Champster]

Thanks Jeff. I won't overlook the 2206. I'm very excited by everything I read about it actually and hoping it will work great. I'm planning on building individual cabinets for the 2206 and the 2123 to compare them, head to head, in their ability to blend with the 2446Be. I'm not out for max SPL. Quality and integration are far more important considerations for me. Making them sound like a single driver without a crossover is the goal. I'm thinking that Drew Daniel's picked the 2123 for a reason but like a lot of us, I'm looking forward to doing my own research.

[Champster]

I've finally built the subwoofer cabinets. I'm not completely done yet, but wanted to post some pictures of my progress. I want to add more ribs to further reduce any possible resonance in the cabinet, add the fiberglas and the wood veneer, driver, cable and connector. The cabinet is 10.25cf gross, less the 6" x12" vent tube, bracing and the .3cf for the rear of the 2245. Net, net I expect to be about ~9cf. This should give me some flexibility to adjust the ultimate tuning.

For those that haven't followed my thread, I am building a 5 way, miniDSP 4x10Hd system using the 2245 (<70hz) in this cabinet. In the main cabinets, I'll use a 2206 sealed (~70 to ~300), a 2123 (~300 to ~1000), a 2446 with TruExtent Be phram with a 2386 narrow dispersion horn (https://www.dropbox.com/s/96hh3vbf496rrel/2386.pdf?dl=0) (~1000 to ~12000) and a 2405 (~12000+).

As always, comments are welcome.

Thanks,
Paul

6310263103631046310563106

[Champster]

a few more pictures...
63107631086310963110

[Lee in Montreal]

Nice work ;-)

[Champster]

Nice work ;-)

thanks Lee. I your experience do you have any suggested methods for fiberglass? I see some just apply a thin layer over all internal surfaces, others utilize bulk amounts to fill pockets inside the cabinet. To me, the bulk method seems to offer the acoustic energy more fiberglass material to deal with, thus making it "seem" like a larger cabinet.

Thank,
Paul

[Lee in Montreal]

I would suggest applying some Dynamat tar panels to make them more innert. Fiberglass? I would advise against it but some like it. I suggest using medium density foam.

[Champster]

Yeah I love dynamat. It works so well. I've never used foam. It probably works fine too.

[JeffW]

Makes you wonder what JBL, with all their design and engineering expertise, use.

1400 Array, See p2 (http://www.audioheritage.org/vbulletin/showthread.php?10643-1400-Array)

K2 9900, Scroll to Post #9 (http://www.audioheritage.org/vbulletin/showthread.php?24086-K2-s9900)

4348, p2 (http://www.audioheritage.org/vbulletin/showthread.php?17053-4348)

Food for thought.

[1audiohack]

Makes you wonder what JBL, with all their design and engineering expertise, use.

1400 Array, See p2 (http://www.audioheritage.org/vbulletin/showthread.php?10643-1400-Array)

K2 9900, Scroll to Post #9 (http://www.audioheritage.org/vbulletin/showthread.php?24086-K2-s9900)

4348, p2 (http://www.audioheritage.org/vbulletin/showthread.php?17053-4348)

Food for thought.


Right?

[Lee in Montreal]

Makes you wonder what JBL, with all their design and engineering expertise, use.

Corporations don't always want what is best for consumers. They much prefer taking care of their benefit margins. That you probably know. :D

Fiberglass wool costs perhaps 1/20th what medium density foam costs. Therefore, fiberglass is not necessarely better, it is just way cheaper and probably the reason it ends up in JBL cabinets. And in my case, I don't want fiberglass particles on my skin and in my lungs. :eek:

Many companies have been using more expensive foam for decades. B&W and Kef are two of them. And most likely almost everyone else now.

http://www.htguide.com/forum/attachment.php?attachmentid=9609&stc=1&d=1175535226

I buy my foam from flight case makers.

http://www.flightcase.com/Assets/News/how-to-create-custom-foam-inserts/Howtocreatecustomfoam_L.jpg

[grumpy]

Also, fiberglass does not deteriorate the way foam can. That said, I was quite happy to find the foam inside my recently acquired KEF systems had retained their suppleness, while the same can not be said for the surrounds). Material science gets funny when decades are involved :) Speculation (mine) that fiberglass is often used as it does the job -and- is cheap seems like a reasonable trade off/choice, with a number of alternatives available to designers and DIYers.

[Lee in Montreal]

I still have three sets of mid-1970s Kef speakers on daily use here. The foam in the cabinets has barely dried out. The woofers and mid drivers still have perfect butyl rubber surround. That's 40 years of duty. Nonetheless, some speakers like the 107/2 had a different type of foam suspension (not rubber) that was in the same material as the one found on 2235 and 2245. Two small woofers opposing each other on a vertical configuration. Sadly, their suspension is known to deteriorate over time.

http://img.photobucket.com/albums/v668/Lee_Vuong/Kef%20speakers/Kef_Brigade.jpg

[JeffW]

Corporations don't always want what is best for consumers. They much prefer taking care of their benefit margins. That you probably know. :D

Fiberglass wool costs perhaps 1/20th what medium density foam costs. Therefore, fiberglass is not necessarely better, it is just way cheaper and probably the reason it ends up in JBL cabinets. And in my case, I don't want fiberglass particles on my skin and in my lungs. :eek:



There was a paper here once, I can't find it any more, that went into the thermodynamic properties of different materials for lining speaker enclosures. Fiberglass was much better at converting sound energy to heat than the usual suspects like polyfill. Polyester fibers just didn't have what it takes. Yet polyester fiber fill is cheaper than fiberglass. If cheap was the driving force, seems like polyfill would be in JBL cabinets.

I don't recall if any foam products were tested in the paper, but the type of foam is pertinent in sound absorption. The wrong type of foam, even if it looks good, can act as a reflector.

I didn't find the product sheet on the 66000/67000 series, but pretty sure they have fiberglass lining, too. Did JBL really go all out on these systems only to save a few bucks on the lining of the enclosures, or is fiberglass the correct material after all? :dont-know:

[Champster]

Thanks for your comments here everyone. There are certainly no shortage of opinions on this topic. Just for kicks, I'm going to remove the drivers from my B&W HTM1 tonight to see what they use. I'll post pictures.

Does anyone other than Lee and me use Dynamat or something more like Black Hole (http://www.blackhole-america.com/)?

[JeffW]

Thanks for your comments here everyone. There are certainly no shortage of opinions on this topic. Just for kicks, I'm going to remove the drivers from my B&W HTM1 tonight to see what they use. I'll post pictures.

Does anyone other than Lee and me use Dynamat or something more like Black Hole (http://www.blackhole-america.com/)?

I think it's more than one topic. There are lots of ways to deaden a speaker cabinet, but that's not really what the fiberglass is used for. You get more apparent enclosure volume with a fiberglass lined enclosure, so some of the volume you lose to drivers and braces and such can be reclaimed. It's not really "stuffing" like a sealed cab, and it's not really "deadening" like Dynamat. There used to be threads or links or something that was more easily located around here that spelled all this out, but I'm not finding it.

[Champster]

Attached are pictures of my B&W Nautilus center channel. To continue the general topic of cabinet treatments, they use foam blocks and pads that are glued to the wood and don't use any cabinet deadening material like Dynamat. They do use lots of internal bracing and have many curves to the cabinet design to add strength and reduce resonances. The interior of this cabinet look very similar to Lee's cabinet with the exception that Lee's is stuffed full of foam. B&W's allows for air movement. I don't know whether Lee's cabinet is sealed or vented but the B&W is sealed with each woofer and the midrange having their own enclosures.

So this is interesting. JBL's top of the line uses fiberglass, whereas B&W uses foam. Both only line the walls rather than stuff the cabinet. Also interesting to note is the varying thickness of the wood at the opening of the hole for the speaker.

63115631166311763118

[Lee in Montreal]

Parts Express sells "egg crate" foam. Not cheap

http://www.parts-express.com/acoustic-sound-damping-eggcrate-foam-1-1-2-x-12-x-12-2-pieces-ul-94--260-517

http://i.imgur.com/8NueLh.jpg

Walmart can supply "egg crate mattress liner" for much less. It is white and very cheap. Panels are about 6'x5' ;-)

http://www.clivir.com/temp/cache/16d915172b307bc00a4745db7a04c1f7.png

http://www.memoryfoamwarehouse.co.uk/media/catalog/product/cache/1/thumbnail/9df78eab33525d08d6e5fb8d27136e95/e/g/egg-box-topper-detail_3.jpg

[tomee]

yes, I've seen that paper too. Acoustically FG was superior to almost everything else, except maybe lambs wool?? but, I don't recall if any of the newer special acoustic foams were included.. FG is also fire-resistant, which is important if you expect crossovers and voice coils to over-heat and possibly ignite (ie abused/pro-sound). (Yes, wood, burns, but most foam plastics give off toxic fumes when they burn - this was the potential liability issue once explained to me by a commercial designer for the choice of FG over foam inside a pro-sound cabinet.)

(edit: I think the discussion on FG vs polyfill is in the Vance Dickason Loudspeaker Design Cookbook.)

edit 2: in a sub, do you need any acoustic damping? if crossed over below 100 HZ there's not much HF reflections to damp out??



There was a paper here once, I can't find it any more, that went into the thermodynamic properties of different materials for lining speaker enclosures. Fiberglass was much better at converting sound energy to heat than the usual suspects like polyfill. Polyester fibers just didn't have what it takes. Yet polyester fiber fill is cheaper than fiberglass. If cheap was the driving force, seems like polyfill would be in JBL cabinets.

I don't recall if any foam products were tested in the paper, but the type of foam is pertinent in sound absorption. The wrong type of foam, even if it looks good, can act as a reflector.

I didn't find the product sheet on the 66000/67000 series, but pretty sure they have fiberglass lining, too. Did JBL really go all out on these systems only to save a few bucks on the lining of the enclosures, or is fiberglass the correct material after all? :dont-know:

[1audiohack]

[QUOTE=Lee in Montreal;366136]Parts Express sells "egg crate" foam. Not cheap

http://www.parts-express.com/acoustic-sound-damping-eggcrate-foam-1-1-2-x-12-x-12-2-pieces-ul-94--260-517

Walmart can supply "egg crate mattress liner" for much less. It is white and very cheap. Panels are about 6'x5' ;-)

Hi Lee and all;

I do note that you closed with a wink so this shouldn't be seen as argumentative. There is enough "angertainment" going on elsewhere here.

Proper acoustical foam is reticulated urethane (fully open cell) while the mattress foam is usually latex foam (nearly fully closed cell bubble foam. The little balloons offer the physical support for the job of keeping you off the hard and or cold floor.

The acoustical properties are nowhere near the same. I bought the majority of a decommissioned mixing/mastering studio's acoustical treatment and spent a weekend measuring it along with some other stuff I have. For fun I included some of the mattress foam and other egg crate type things, like egg crates, and found them to be, on axis simply a reflector and off axis a very very narrow band diffusion devise. Practically useless even if free.

I wish I had more time to test things like this and had the time to document more of it besides the saved file notes. It's fun and the asurety going forward is nice to have.

In the end? Make mine fiberglass.

All the best,
Barry.

[JeffW]

yes, I've seen that paper too. Acoustically FG was superior to almost everything else, except maybe lambs wool?? but, I don't recall if any of the newer special acoustic foams were included.. FG is also fire-resistant, which is important if you expect crossovers and voice coils to over-heat and possibly ignite (ie abused/pro-sound). (Yes, wood, burns, but most foam plastics give off toxic fumes when they burn - this was the potential liability issue once explained to me by a commercial designer for the choice of FG over foam inside a pro-sound cabinet.)

(edit: I think the discussion on FG vs polyfill is in the Vance Dickason Loudspeaker Design Cookbook.)

edit 2: in a sub, do you need any acoustic damping? if crossed over below 100 HZ there's not much HF reflections to damp out??

Thanks tomee. If that's correct, then that would explain why I remembered reading it but couldn't find it here. As for subs, I found the 2245 sub paper on the computer at home and it mentioned lining the sub enclosure with FG except for the back of the baffle.

[Champster]

Thanks tomee. If that's correct, then that would explain why I remembered reading it but couldn't find it here. As for subs, I found the 2245 sub paper on the computer at home and it mentioned lining the sub enclosure with FG except for the back of the baffle.

Very well then. That was a very interesting discussion. Thanks to everyone for their contributions.

My main cabinets are well underway at this point and I'll be posting pictures in a week or so.

thanks
Paul

[Champster]

Given the many changes to the components in this build (and my inability to change the Title of the thread), I've decided to start fresh with a more current version of the system here. (http://www.audioheritage.org/vbulletin/showthread.php?36224-Build-Thread-continued)

Thanks,
Paul