JBL 4675C with TAD 4002 compression driver - Page 2

The warts I see with the Yorkville Unity are the following:

1. Directivity which waistbands significantly. Danley has counteracted this in his Synergy designs by widening the outer portion of the horn.
2. Port holes that aren't shaped optimally. Can be reshaped to look more like Synergy ports.
3. Crossover is weak. Easy to fix.

The only thing not fixable on the U15 is the horn profile. It isn't the end of the world, but a bit of an issue for me. The good thing is that you are buying very good drivers for the money and it is principally the same as a Synergy design. The details are just a little different. Of course, it doesn't require the woodworking effort of a Synergy clone.

The other issue is that it is a relatively small horn for utilizing Unity/Synergy principles. IMO, the biggest benefit of the Synergy design in a home is the ability to maintain point source controlled directivity over a very wide frequency range. Is there any point in using a large format CD like a JBL/TAD on a horn that is only good down to 1000hz? I don't know of way besides Synergy/Unity to hold horizontal from 300hz-18khz. You could use a 2" horn to get pattern control down to 300hz, but it is ugly above 6khz and expensive. You could use a separate midhorn but that gives lobing issues and isn't point source. Coax gives point source over that range, but directivity is messy. Synergy is about as close to perfect that I can imagine. 36" wide LCRs holding pattern to ~300hz is what I want. Of course that isn't going to work in a living room and even Danley doesn't sell something like that because it isn't practical in pro.

I am giving thought into building a new LCR setup for my home theater. Those JBL 2446 CD's with the Truextent Beryllium diaphragms matted with the IWATA 300 horns looks to be a heck of a performer! Is that price in the link above for each IWATA 300 horn or is that a pair? Doing a quick google search for the JBL 2446 CD was a serious let down as those things cost over $800 bucks ea, if I read that right! Am I mistaken on that?? What are the general retail prices on those? The Truextent Beryllium diaphragms are expensive enough. If I were to fork out the dough for a new trio of 2446J CD's along with a trio of Truextent Beryllium diaphragms and a trio of IWATA 300 horns, all used as mid range drivers, what would be a good HF driver/horn combo for the top end? I had been looking into a trio of B&C DE750TN's mated with Dave Harris' ElipTrack 400 horns along with a B&C DE10TN tweeter with the stock B&C horn for the HF's and also a quad 10" woofer bottom LF drivers. I would guess that the 2446/Truextent/IWATA combo would probably blow the later choice completely out of the water??

The 2450-SL is a better choice....
http://www.ebay.com/itm/270945897602?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I have 2-2447 and 2352 horns (including 2509 brackets) I'd be happy to sell you.
Edited by Wrager - 11/8/12 at 5:10pm

#1) JBL 2446 CDs in perfect condition often go for as little as $350 on EBay.

#2) Last I knew the Truextent website does not show the JBL 2450 CD body on their list of supported CDs.

#3) The IWATA 300 price is for one.

#4) If I were to buy a pair of new CDs in which to put beryllium diaphragms I be looking hard at Radian 950PBs. They are a good value and a good product!
_____________
Best Regards,
Carl Huff

So you think a Radian 950PB with a Truextent Beryllium diaphragm matted with a IWATA 300 horn, would be a tough combo to beat? Are there any other cheaper diaphragms that offer comparable sound quality to the Truextent Beryllium diaphragms? That combo of drivers/diaphragms/horns for the sole purpose of being used to cover the mid-range frequencies comes to a grade total of $1,400 bucks per speaker, and that doesn't even include a comparable tweeter/horn combo or the LF drives. Dang, this gets expensive real quick! Speaking of HF drivers/horns, what would be a good mate to the Radian/Truextent/IWATA combo?

Marty-

I would suggest avoiding uncoated titanium diaphragms if you can. Whether they are B&C's or JBL's, there are better options. Either find some aquaplas titanium JBLs, 18Sound TiN or aluminum drivers or, if budget allows, use a beryllium diaphragm.

Carl is right, the best driver to use with a Be diaphragm is the Radian 950pb. The newer JBL's and Radians have superior phase plugs to the older 2445/6/7. The 2450SL is a very nice but it is a 1.5" throat so I don't think it will work with the Iwata-300. I would generally suggest using a 1.5" exit angle over 2" given the choice though. You will get better response in the upper frequencies. Of course if your horn is only made in one throat diameter you might not have a choice.

The Radian's are $400 and come in either 1.5" and 2.0" exits. They use a diaphragm that is interchangeable with the JBL 4" diaphragms hence its compatibility with the Truextents. Unless you can get one of the newer JBLs for less than $400, I would stick to the Radian.

Edit: one other thing. I would suggest using the Iwata/Radian combo from about 500hz and up and skipping the tweeter above it. IMO that is a holdover from when large format drivers couldn't play the upper end combined with some manufacturers wanting better specs for their marketing literature.
Edited by coctostan - 11/8/12 at 6:25pm

Ok, so you think going with a 2 way design using the IWATA/Radian/Truextent combo would be the way to go over a 3 way design? Point taken about crossing over at 500hz and letting that combo handle everything above that. This is going to be a major investment for me, still mulling over how much better this combo would perform compared to the much cheaper B&C/ElipTrack combo. If it is substantially better, then I will just have to start saving!

This thread is making want to reconsider not building a midhorn for my system and just using the 2445 + 4x 2226.

scott,

have you clicked on this: http://www.cowanaudio.com/

unity the finale on the left hand tab.

too bad they aren't a little larger and don't have a little wider directivity.

i'm not sure of the details, but while the horn is a little small, http://www.aespeakers.com/pics/PICT2140.JPG

thread: http://www.diyaudio.com/forums/multi-way/127121-once-again-studio-monitor-2.html

Many, many times, John. The Unity system is what turned me on to high sensitivity designs pretty much.

I don't know anything about the ElipTrack horns. Do you have a link?

First, IMO 2" throat horns are outdated as is the use of a supertweeter crossing around 8khz. The only case for a 2" horn is as a low midrange covering ~300hz-1500hz. I personally think JBL is behind the curve in their K2/Everest approach although I understand it is hard to sell a $50k speaker that rolls off at 16khz and instead needs to be flat to 50khz. That is just marketing BS.

Modern large format drivers are almost exclusively 1.4 or 1.5" exits which allow for pretty good extension to the highest required registers. What you basically have is a choice between a 1" throat small format or a 1.5" throat large format. The 1" allows for good response and directivity up to about 18khz while the 1.5" will go to about 13khz before beaming badly. On the other end, 1" exit drivers won't play below about 800-900hz whereas most 4" diaphragm 1.5" throat drivers will play down to 400-600hz. It is a tradeoff.

The other part is that the small CDs can use inexpensive but quite nice sounding mylar diaphragms. The large format drivers must use a metallic diaphragm which is far more costly. This is why titanium is used. It is lower performance, cheaper and super durable. This is good for pro applications and bad for home use. The exception being coated titanium like JBL's aquaplas or 18Sound's TiN. Aluminum sounds better than titanium, but doesn't play the upper HF well and is less durable so fewer companies are using it. I believe just 18Sound and Radian use it now. The ultimate option for home use is beryllium. The downside is that it is very expensive.

So what you should do should be based on budget and tradeoffs acceptable to you. With a lower budget, I would stick to a high quality 1" design using the SEOS-15 and a very nice woofer. I would suggest doing this over the Iwata with a titanium diaphragm. If your budget is higher and you don't mind the narrow horizontal beamwidth of the Iwata's top end, I would use it with the 18Sound ND2060A. It is an aluminum diaphragm and I've seen it for sale at $300. For $400 you could do a Radian 950PB. It might play better lower since it has a 4" diaphragm vs the 3" on the 18Sound. These are both better than the DE750TN. One big advantage of going with the Radian is that you could upgrade to the beryllium at a later date.

I personally prefer a more constant directivity horn so Iwata is not what I would choose, but that is kind of a personal choice. Among the non-constant directivity horns, the Iwata would definitely be a top choice. I don't know anything about the ElipTrack.

There are two other routes that are IMO better than all of the above for pure performance. One is to use a cone midhorn to cover about 300hz-1500hz with something like a SEOS-12/15 or a E-JMLC-1000 and your choice of high quality 1" CDs. The tough part is that you would probably need to build your own midhorn or base it on something like the Pi 7 cornerhorn. You also need a 3-way crossover which complicates and adds cost.

The final option is a synergy clone which is IMO the pinnacle but not easy to pull off on nearly every front (finding right mids, crossover, woodworking). It is really the best of all worlds.

The Catalysts amaze me on a regular basis,...and I'm far from fully optimized. The DSP secret sauce Mark offers seems to be an ideal set of compromises to my ears.

I do appreciate the invite. Likewise, I could use any constructive input as well.

Thanks

Somewhere, I recall seeing an illustrated comparo/shootout, of a Geddes Abbey, up against the Yorkville (mybe another speaker too), in a good room, with some good gear. The Yorkville was found to be quite colored, iirc. Clearly, the superior cabinet of the Geddes, contrasts strongly to the pro oriented Yorkville box (resonance, diffraction, throat geometry).

Exciting design nonetheless. All good points quoted above.


What I find quite exciting is the fact that a modestly sized performance (live or DJ) can offer up superb sound quality (in the right hands) unheard in previous years. A single top box per side, mated with ample subwoofage, could sound phenomenally good indoor or out. I got into DJ'ing weddings, parties, etc, for two reasons. Primarily because of the horrendous sound quality I'd encounter at such events. Secondly, to experiment with high performance sytems, subwoofer systems and experiments, ...in various iterations and environments. I never made money, but I brought the finest gear, carefully set-up and optimized to the environment. Funny, much to the dismay of some clients, I'd turn down events if the room wasn't ideal for me!

Anyway, I wish some of these sweet ass designs were available when I was performing those experiments.

A pair of Yorkville Unity, or Danley Synergy Horns, complemented by a killer subwoofer system, would make for a night of fun!


Thanks

Did Mark optimize the DSP for your room at all? The value of design and optimization is significantly under estimated by DIYers. Everyone wants to just throw money at a solution with the best drivers when those differences are generally small.

No, they're stock. I'll adapt my room to them



I value his skill set highly,....that's the thought process that pushed me over the edge to go with his design. His skills in this area are strong. My perspective; the inherent value of the Cat12,...from quality parts,...Janowitz built LF drives, w/motor design by TD, mated to the pro coax. All subsequently tamed and made to play nicely together by Mark.

Thanks

Speaking of 4675C, a while ago it became apparent that my 42" deep JBL 2360's (w/BMS 4590+dual 2226J's) LCR were not going to be shoehorned into a 23.5' deep HT room with 2 rows of seating plus a 3rd row counter. I was in the process of deciding between Erich's SEOS or my Tannoy 12" Duals in place of the 2360/BMS combo (guess I'll save the bigger guns for my next house), then a few weeks ago a pair of used Yorkville U15 Unitys appeared on Amazon for a great price. Couldn't pass the deal up, so they are here now.

After verifying operation at my house for a few days -- on a Denon 20wpc mini-system of all things -- my first real listen was pressing them into duty as sound reinforcement for my high school senior's Halloween party; providing high-quality noise for about 60 freaks dressed in costume in a rented basketball gymnasium. It was short notice as a family friend that is a DJ was going to do sound but got a better (better=paying ) gig at the last minute and cancelled, so I powered them with a vintage '93 Yamaha HT receiver instead of one of my QSC's due to a lack of having a proper preamp available. Even with 80wpc, these things sounded great and received many sound quality compliments from the parent chaperones. Still haven't had a chance to put them in my rig for a proper listen after being out of town for work all week.


The owner of the speakers (DWK) stated they really need to be EQ'd to the room they are installed in.

So far, I really like most of what they are doing, but am aware of their list of caveats (succinctly summarized by Coctostan). I think I'm going to cop out and try to make these work in the HT room...frankly, it will save me a ton of work as well.
Edited by Aaron Smith - 11/26/12 at 1:26pm

Merry Xmas.....

I still own and Love my TAD 4002s

The ghost of Penngray

Penn, where've you been? Haven't seen your monicker in a while.

Whoa there! Penn? Welcome back man.

Good to see you back!

26,746 posts from a join date of 2/06 through 10/11...that's almost 13 posts per day, every day. Doug probably needed the 14 month break to recuperate.

Where have you been hanging out for your audio fix?

lmao....not back. Just dropping by...too many other hobbies, one had to slow down. Time on Audio forums lost out

Hey penn,
Good to hear from you! Hope you are still enjoying the hobby. I have been changing stuff as usual.

Doug-
Sure hope you do have time to come back. You have provided so much good insight over the years! Please stay!

wow, santa penn sighting.

LOL. Nice seeing Penn around again. Penn whats your other hobbies?