Custom TAD-JBL Studio Monitors

[jerry_rig]

Hi everyone. I thought I'd share with you the fruits of my summer weekends. With much planning, guidance and help from forum members -- you know who you are -- I designed and built a pair of custom studio monitors based around a new pair of TAD TD-4003 drivers and solid resin clones of TAD's TH-4003 horns. The crossovers are TAD TN-4 units and I have mixed the 15" woofers: JBL 2234H on top and JBL 2235H on the bottom. Each woofer is in its own chamber and is separated from the other by a slanted, internal double-walled panel.

The boxes themselves are double-walled -- outside 3/4" birch plywood panels each glued to an interior of 3/4" MDF. The veneer is 22.2 mil thick "bubble-free" rosewood from Oakwood Veneer Company (which I highly recommend). The baffles have an extra layer of 1/2" plywood and are 2" thick. The woofers are countersunk 1/2" in order to be flush mounted. The interior is filled with Sonex foam panels. The horn and 2234H on top are connected to a TAD TN-4 crossover mounted inside the cabinet. The 2234H's higher sensitivity matches almost perfectly with the TAD 15" units for which the TN-4 was designed. The deeper reaching 2235H on the bottom is hooked to a 100Hz low pass filter that is wired directly to the lower (jumpered) inputs (very similar to the JBL 4435 except that I'm mixing drivers). I'm guessing these weigh close to 400 lbs each.

Right off, perhaps not surprisingly, they sound fantastic. They have a full-range, clear and coherent sound to them. Very well balanced with a wide and stable image. Even my wife, who rarely comments on the music, noticed a dramatic difference over my previous DIY efforts.

That's enough for now. Time to sit back and listen! Cheers,

Jerry

Here are pics of the cabinets and my workshop:

[hjames]

They look gorgeous - so if they sound HALF as good as they look ... I'm sure they are wonderful! So - they are basically 2 1/2 way speakers? Paired 15s to spread over the low end, and the TAD 4003 on top? ... very intriguing!

[jerry_rig]

Thank you Heather! Yes, that is exactly what they are (2.5 way). I was advised against running both 15s full range in order to avoid lobe effects. The image is better focused and stable with just one (the 2234H) running up to the 800Hz crossover point.

[scott fitlin]

GREAT choice with the TAD - 4003! One of the VERY BEST compression drivers you can get. Known for exactly what you describe, the most coherent, and clearest sound possible. The TAD passive crossovers are GREAT, as well.

VERY NICE LOOKING SPEAKERS, INDEED! Enjoy them, you do great work!


:thmbsup:

[1audiohack]

Those look great! So does your work space. Nice choice for a cabinet saw too!

[scott fitlin]

Nice choice for a cabinet saw too!Yeah right, I noticed that too. Looks like a POWERMATIC! Those are GREAT MACHINES!

:bouncy:

[jerry_rig]

Good eye guys! Yes indeed, the Powermatic PM 2000 with an extra heavy duty 50" extension table. I wouldn't try this with anything less. Thank you all for the kind words.

[scott fitlin]

I am all for it, use the BEST tools you can afford. It definitely makes a difference. I also have a POWERMATIC table saw. I plan to get myself a FESTOOL Router, and a Plunge Cut Saw, too!

Besides audio, I am a TOOL WHORE too! :dont-know:

[Mr. Widget]

Congratulations... and yes they do look pretty damned serious!


Widget

[yggdrasil]

Looking really good. Great toys to enjoy!

[Robh3606]

Very Nice! Bet they sound great!

Rob:)

[spkrman57]

And a great design to go with the looks!

Regards, Ron

[louped garouv]

Thank you Heather! Yes, that is exactly what they are (2.5 way). I was advised against running both 15s full range in order to avoid lobe effects. The image is better focused and stable with just one (the 2234H) running up to the 800Hz crossover point.


great to know, and timely for me!

thanks for sharing your admirable work!

[richluvsound]

love the rose wood ... you have triggered my TAD envy again :D


Rich

[pos]

Very nice speakers!


The deeper reaching 2235H on the bottom is hooked to a 100Hz low pass filter that is wired directly to the lower (jumpered) inputs (very similar to the JBL 4435 except that I'm mixing drivers).
At these low frequencies the 2235H and 2234H have almost exactly the same response and efficiency

[allen mueller]

Great work, I bet the combo of the 2234, 2235 sounds great. I love the dual 2234's in my 4435's. What tuning/volume did you use for each?

AL

[jerry_rig]

Again, thanks to everyone. Both chambers are tuned to 30Hz. It's very hard to tell when they both kick in -- a good thing, I think.

[Mike Caldwell]

Your wood shop looks like an operating room! Oh by the way your speakers look great to!

[cosmos]

Those look fantastic! I'd love to hear them... The combination of drivers is one I have considered and it looks like you have exploited really nice design ideas.

[speakerdave]

. . . . The image is better focused and stable with just one (the 2234H) running up to the 800Hz crossover point . . . .

My experience also with the woofers paralleled in a two-stack arrangement. There is also audibly improved clarity and definition when only one woofer plays to the horn (I'm using 1400nd's). With an MTM arrangement it is slightly better, but in a rather small area. Paralleled drivers have to be operating in full acoustic coupling mode to avoid a blurring effect, which masks the beryllium benefit, and in my experience that is not easy to achieve, and is impossible at the necessary crossover frequency with the woofers separated by a horn of that size. Side-by-side woofers in a two-way ala Augsburger create a footprint that is awkward in a living space, for me anyway, and big heavy speakers that need to be elevated. They also need to be toed in and carefully aimed at the listening position, not a livingroom-friendly form. Your format choice is probably the best one.

Nice work on the cabinets. Your workshop and mine are in different galaxies. Where's all the stuff?

[jerry_rig]

There is stuff all around:

[bigyank]

Truly awesome speakers and extremely nice shop, wow! I am gearing up for a similar project this winter and yours has me inspired now. Only issue I have is my shop is no way even close to yours. :D

One question, any plans for a pair of grills?

Yank

[felixx]

Nice job.
Why did you use 4003 and no 4001?

[jerry_rig]

Why did you use 4003 and no 4001? The TAD TD-4003 is a level above the TD-4001 (or 4002). I wanted the best and originally tried to go with JBL 476Be drivers. But I'm happy with this setup ;-)

Grills are coming soon! I have some beige JBL cloth I'll try first. Pics to follow.

[Audiobeer]

Excellent Job! Love the look and choice of veneers. I would die for the speakers or the shop! Don't you jusy Love enjoying the fruits of your labor!!!

[Ian Mackenzie]

The TAD TD-4003 is a level above the TD-4001 (or 4002). I wanted the best and originally tried to go with JBL 476Be drivers. But I'm happy with this setup ;-)

Grills are coming soon! I have some beige JBL cloth I'll try first. Pics to follow.

Hi Jerry,

I am kinda in the same boat.

You haver done a really good job here. If possible and (when you get a moment) can you post some drawings.

Ian

[jerry_rig]

If possible and (when you get a moment) can you post some drawings.


Hi Ian,

Here they are. In the diagrams, the blue panels are 3/4" MDF. The others are 3/4" birch ply, except for the inside front baffle, which is 1/2" ply. The upper divide -- just below the horn -- has cutouts (12" x 6") in order to accommodate the crossovers and to increase the volume of the upper bass driver chamber. When viewed from above, it looks like an "I". If was putting the crossovers outside (or running active) I would drill several large holes instead. Bracing is not shown, but every large panel has 4" wide plywood braces spanning the facing panel. All panels are glued together using multiple clamps. All joints are glued as well. Except for the rear access panels, there are no screws or nails used. Thanks for asking!

Jerry

[Woody Banks]

Your wood shop looks like an operating room! Oh by the way your speakers look great to!

I agree with Mike 100%. Beautiful speakers! I think the rosewood and black horns look great together. Your operating room shop makes me feel a bit guilty. My shop looks like something you would see on an episode of the Hoarders. :o:

[martin_wu99]

good job!

[dangerisland]

Those are beauties! I'm preparing to build a similar system. I've got a 1601bs (2), TD-4001s, TH-4001s, and the same TN-4 that you have. I'd love to hear about your box dimensions, port specs, etc. Especially if you're happy with the result! I'm considering using a pair of JBLs to cover the sub-range just as you have. So, I'd really like to pick your brain for obvious reasons. If you've already moved onto another DIY project and have lost the gumption to discuss this one - no problem. I understand.55073

[hatrack71]

I am all for it, use the BEST tools you can afford. It definitely makes a difference. I also have a POWERMATIC table saw. I plan to get myself a FESTOOL Router, and a Plunge Cut Saw, too!

Besides audio, I am a TOOL WHORE too! :dont-know:

Hah, me too!

[Don C]

Those are beauties! I'm preparing to build a similar system. I've got a 1601bs (2), TD-4001s, TH-4001s, and the same TN-4 that you have. I'd love to hear about your box dimensions, port specs, etc. Especially if you're happy with the result! I'm considering using a pair of JBLs to cover the sub-range just as you have. So, I'd really like to pick your brain for obvious reasons. If you've already moved onto another DIY project and have lost the gumption to discuss this one - no problem. I understand.

I'm pleased to have discovered a new JBL fan neighbor. You wouldn't happen to be associated with mfsl? Sorry for going off topic.

[jerry_rig]

Those are beauties! I'm preparing to build a similar system. I've got a 1601bs (2), TD-4001s, TH-4001s, and the same TN-4 that you have. I'd love to hear about your box dimensions, port specs, etc. Especially if you're happy with the result! I'm considering using a pair of JBLs to cover the sub-range just as you have. So, I'd really like to pick your brain for obvious reasons. If you've already moved onto another DIY project and have lost the gumption to discuss this one - no problem. I understand.55073

Hi Danger,

Sounds like a great project.

As for mine, the exact dimensions are given in the thread below. It roughly works out to 5 cu. ft. for each woofer. The ports are tuned to 28 Hz on top and 24 Hz on the bottom. I used 4" Precision Ports (four per speaker cabinet) cut to length.

In the intervening year and a half, the speakers have undergone a few changes, some of which are documented in other threads on this site. But to re-cap, I:

a) replaced the JBL woofers with TAD speakers: 1601c (very rare!) on top and 1601b on the bottom. This required routing the recesses a bit.

b) moved the TN-4 crossover from the inside and mounted it on the rear. Also, I beefed up the internal bracing after freeing up some room.

c) replaced the passive internal high-pass crossover (used on the bottom 15s) with an external active Ashley XR-1001 used for low pass only at a 50Hz crossover point. This is connected to a large Krell power amp. I'm using a tubed Air Tight ATM-2 (run full range) on the tops (i.e., to the TN-4). All are driven by a Pass Labs XP-20 preamp.

d) replaced all wiring with Kimber Cable 8TC.

e) added TAD ET-703 super tweeters with a custom crossover. These replace a pair of Tonian Labs ribbon tweeters I've had in place for the past 14 months. I'm still dialing the ET-703s in, but their potential is clear.

As the above makes clear, I have definitely not moved on! Particularly after a buddy helped dial the subs in with an audio analyzer, it is hard to emphasize the quality of sound I'm getting. Suffice to say that my audiophile friends who have auditioned them claim this is the best system they have ever heard. Not to tout my own horn, but I have yet to hear a more resolving system. I hope this helps.

Jerry

[Ian Mackenzie]

Outstanding.:)

[richluvsound]

Hah, me too!


I have the saw and track .... router will have to wait till my other one dies . Worth every penny !

[maxserg]

I can just say that I would like to have you as my close friend and not far from where I live!!! Great build and high knowledge! :)

[Champster]

Jerry,
Those are fantastic! You mention you used a resin clone horn. How did you do that or did you buy them?
Thanks,
Paul

[Lee in Montreal]

Jerry,
Those are fantastic! You mention you used a resin clone horn. How did you do that or did you buy them?
Thanks,
Paul

Yup. also interested here. Has anyone made resin copies, and we're not aware of ? ;-)

Lee

[jerry_rig]

All,

Thanks again for the nice comments. I very much enjoyed building and, more importantly, listening to these speakers. The horns were made by a very prominent member of this forum. I will let him come forward, if he chooses.

As the result of a move from upstate NY to SW Florida, I sold the TADs to a friend. Some of the components have made their way to other forum members. I decided to try a different route: I purchased a new pair of Magico S5 speakers. Needles to say, this is a much different approach. And I am loving them so far.

Best,

Jerry

[Champster]

All,

Thanks again for the nice comments. I very much enjoyed building and, more importantly, listening to these speakers. The horns were made by a very prominent member of this forum. I will let him come forward, if he chooses.

Fair enough is suppose. I sure would like to hear more about their construction rather than the absolute merits of the similarity to TAD's design.


As the result of a move from upstate NY to SW Florida, I sold the TADs to a friend. Some of the components have made their way to other forum members. I decided to try a different route: I purchased a new pair of Magico S5 speakers. Needles to say, this is a much different approach. And I am loving them so far.

I'll bet you're loving them! I have always appreciated the Magico build approach. Their commitment to resonant free cabinetry is matched by very few manufacturers in high end audio. I would, however, have liked to see you step up to the the Ultimate III... LOL

Paul