Rerurn to Romy the Cat's Site

Horn-Loaded Speakers
Topic: Pham Thanh Cuong's playback from Vietnam.

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Posted by Romy the Cat on 12-21-2010
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Pham’s installation did pop up at my site before, primary in context of the illustration of what “those brainless Goto people do”. During the last year or two Mr. Cuong made some changes that I feel worth to note and to discuss.

http://www.theanalogdept.com/pham_thanh_cuong.htm

I open up a tread dedicated to Pham Thanh Cuong's installation. The idiots who published Pham’s pictures and descriptions filed to talk to the guy and to print his thoughts. The morons feel that brand and models are meaningful and this is all that the morons care about.

So, I offer to go beyond the "stupid bumper sticker audio intelligence" (TM) and to analyze what Mr. Cuong was trying to do, what and how he does. I have some of my thoughts and I will upload them later on when I have time and a mood to type them.


The Cat

Posted by Romy the Cat on 12-22-2010
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 A few things I would like to say in context of Pham’s playback.

I will leave his infatuation with turntables alone – man like to collect turntables and he within his constitutional right to do whatever makes him happy. The problem that I see is that in context of our objectives Pham’s tendency to museum TTs deluded the message. After all those pictures and accumulation of brand it is not know what he listen, what is his arms for what purpose. If the man lay out what TT, arm and needle he use for this or that satiation then it would indicate where he stay and what he is getting, or trying to get.  If it were some then it might be mutually educational.

Electronics, it is not clear what he uses but I see a bunch of low power tube amps at the shelf. Since he uses Accuphse DG-38 processor for crossovering then he is unquestionably multi-amping. The list names a bunch of DIY tube amp on 2A3, 211, parallel 2A3. 300B. I guess the do the job. I also guess that since Pham did not implement his second order crossover in his DIY tube amps but use Accuphse D-crossover then he use the Accuphse also for room correction purposes. I made this conclusion based upon the fact that Pham did not call his Accuphse as a crossover but he calls it as a “voicing equalizer”. I have no idea why he needs to equalizer the things he has so many channels ….

The Pham Acoustic System is the most interring thing on all of it of cause. Basically on the page presented two systems:

 Low bass: Under 71Hz – Driver Fostex FW800N 31.5 in. 
 Mid bass: 71Hz to 400Hz – Driver JBL 1500AL 
 Mid low: 400Hz to 1.600Hz – Driver Westrex T530A 
 Mid range: 1.600Hz to 5.000Hz – Driver Jim Lansing 375
 Mid high: 5.000Hz to 8.000Hz – Driver Jim Lansing 175 
 Treble: 8.000Hz to 12.000Hz – Driver Fostex T500Mk2 
 Tweeter: Upper 12.000Hz – Driver Mewon Ribbon TS01

And:

Low bass: Under 71Hz – Driver Fostex FW800N 31.5 in.
Mid bass: 71Hz to 500Hz – Driver JBL 1500AL with enclosure JBL 4344.
Mid low: 500Hz to 1.600Hz – Driver Ale 7550P with horn Goto S300.
Mid high: 1600Hz to 6300Hz – Driver Goto SG 370 with horn Goto S400.
Treble: 6300Hz to 10000Hz – Driver Fostex T500Mk2.
Tweeter: Upper 10000Hz – Driver Mewon Ribbon TS01.

It is obvious that one comes after another but the way the page organized it is not clear which system came first and which later. I am not going to make a guess but would like to look into both.

Both systems feature a single bass horn with Fostex 30” driver. My initial sentiment was that this is not horn but rather an infinite baffle as this horn has no depth. Then in the night picture on the site I recognized that it has some depth and the text describes it as 6 feet long. It is still very shallow horn but it is not clear what Pham is trying to do with it. This 30” Fostex has very light and very flexible cone that has a LOT of break up. When you punch the cone with your am at one location then you just do indentation under your hand but do not displace the whole diaphragm. This driver in my view need to be use very low and with very sharp filter, not allowing to it to do any HF. Pham use his Fostex 30” at 71Hz and 12db/oct. This is interesting. Since he stays at 71Hz not at 70Hz then I think this is an indication of deliberate precision. So, question is: can Fostex 30” in Pham case to cover midbass of Pham did it because not of his other channels can do midbass. I think the last one but truly to answer this question might be only the man himself.

The 71Hz to 400Hz region in both cases is covered by JBL 1500AL with JBL 4344 box. I love the older 1400ND JBL driver and I guess the 1500AL is a newer version. The JBL 4344 box is kind of funny little ported box. I presume Pham loves the sound of it. There is a picture of looks like 70Hz curved horn but there is no information about it.

Then Pham has his version of my Fundamental Chanel. In one case it handled by Westrex T530A driver and in another by Ale 7550P. In case the Westrex it looks like it loaded onto a much larger curved horn. The horn looks like 75-80Hz horn but he loads into it 400Hz driver with second order. What a waste of horn!!! On another side the use of Ale 7550P sounds more appropriate for Goto S300 horn.  I hate Goto horn but at least it is not as huge waste of the horn size.

Then we have MF devised in one case by :

Mid range: 1.600Hz to 5.000Hz – Driver Jim Lansing 375 
 Mid high: 5.000Hz to 8.000Hz – Driver Jim Lansing 175 
 Treble: 8.000Hz to 12.000Hz – Driver Fostex T500Mk2

And in another case by:

Mid high: 1600Hz to 6300Hz – Driver Goto SG 370 with horn Goto S400
Treble: 6300Hz to 10000Hz – Driver Fostex T500Mk2

Pham’s preference for using the Fostex T500Mk2 in upper range is obvious.  I do not know this driver. I used Fostex 90 and Fostex 900, not the T500Mk2. The switch from JBL 375/2440 to Goto SG-370 (or vice versa) is notable. I have no idea what JBL 175 does in there in such a narrow bandpass.   Interesting that using Goto he did not allow Goto to run over 6300Hz. It might be because he so much like his Fostex T500Mk2 or because he find that some inadequacy of Goto performance ay upper range. In any case the credits I think shall go to the Fostex T500Mk2.

For HF Pham uses Mewon Ribbon TS01 in both cases. I do not know what it is. On the picture it looks like a wide ribbon, something that would be more suitable for lower crossover point, but you never know…

In either case the channels are not time-aligned and use with random lateral offset. I presume that timing is done by digital crossover, if not then this installation is just pile photogenic garbage. It would be interesting to see Pham’s choose for amplification for each channels and if he used DSET techniques and optimized in any way his DIY ams for specific channels, and if he did then how.

In my view the biggest concern of my in this installation is a lacking of upper-midbass channel.  Pham use the JBL 4344 box and I in my estimated he drivers a LOT of power over it.  I think the upperbass/midbass horn is what doctor order for this playback. He has that larger curved 75-80Hz horn that is currently is wasted for that Westrex T530A compression driver with 400Hz cut off. I think if Pham load this horn with something of those Japanese compression drivers that can go for 60-70Hz    then he will take a full advantage of that horn. Of cause then he will hit that “70Hz horn syndrome” when the horn is too bit to be located under HF but there is nothing to put in there… Well, Pham is not alone with it….

That were my thoughts that I had what I was looking at Pham installation…. If someone know him then bring his in as I would like to hear about his thoughts regarding JBL 375 and SG-370 differences, about Fostex T500Mk2 advatage and about use of Fostex 30” in THAT horn.

Rgs, Romy the Cat

Posted by haralanov on 12-22-2010
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 Romy the Cat wrote:
I presume that timing is done by digital crossover, if not then this installation is just pile photogenic garbage.

Even if he has his channels time aligned at digital domain, the fact that they are arranged in the horizontal plane, especially with the tweeters placed on the outer side in context of the other channels, makes his system absolutely worthless, no matter what kind of drivers he uses. Fostex T500a MkII crossed at 6300Hz? That is original !! That tweeter produces unbelievably mechanical and hard sound when used so low, and it also runs out of steam below 9-10kHz. I can very easily imagine how this system sounds like…

Posted by Romy the Cat on 12-22-2010
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 haralanov wrote:
Even if he has his channels time aligned at digital domain, the fact that they are arranged in the horizontal plane, especially with the tweeters placed on the outer side in context of the other channels, makes his system absolutely worthless, no matter what kind of drivers he uses. Fostex T500a MkII crossed at 6300Hz? That is original !! That tweeter produces unbelievably mechanical and hard sound when used so low, and it also runs out of steam below 9-10kHz. I can very easily imagine how this system sounds like…
 Probably, I do not know. My Fostex T900 sounded as you described and it was useful only from 10K. The T90, the cheaper they had was BTW much better driver then the most expensive models. I heard that Fostex when they went for MkII did change a lot but at that time I already did not care about Fostexs and never tried them. The horizontal plane? Well, this is what those guys do not get. Go you even seen ANY user of expensive Japanese drivers who get it? This is the whole problem with those “Goto-level” people. They stick those ugly green drivers in the most visible place and create the stupidest installations imaginable. Saying it the people who produce Goto drivers do not believe that amplifiers make any difference… Still, I find it interesting that Pham did not allow his Goto drivers to run too high…

The Cat

Posted by jessie.dazzle on 12-22-2010
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Though he seems to like running several TTs in parallel, I do not interpret Pham's page to show that he is running more than just one horn system; what I see is an evolution of a system. It looks like, in its latest iteration (under the heading "System Update 9/29/10"), Pham has abandoned the Westrex/Lancing drivers as well as the wooden horns, both large and small, in favor of the Goto/ALE hardware. So to be clear, it seems he moved from Westrex/Lancing toward Goto/ALE. 

In fact, what is left with regard to speakers and horns is really quite sparse; Look at it (latest photos); you end up talking about MF. Ok, no real criticism here; the smaller horn is doing most of the work, which is fine, and the larger horn works over a very narrow bandwidth and is a sort of Fundamentals channel; it is borderline too small if being asked to produce 500Hz but it might work. These are the system's only real horns. I see it as a one-and-a-half-horn-system backed up by the JBL boxes and a tweeter, so a kind of 3-way system. The large central bass driver might contribute, but I'd bet the JBL boxes can go lower with higher SPLs, though probably not as cleanly. Other than the move from Westrex/Lansing to Goto/ALE, is there anything here that might warrant discussion? 

It might be interesting to note what has remained in the system from day one: 
  
- Low bass: Semi-Horn-loaded Fostex FW800N (31.5")
- Mid bass: JBL 1500AL driver in JBL 4344 enclosure
- Treble: Fostex T500Mk2
- Tweeter: Mewon Ribbon TS01
   
Haralanov wrote:
"...Even if he has his channels time aligned at digital domain, the fact that they are arranged in the horizontal plane, especially with the tweeters placed on the outer side in context of the other channels, makes his system absolutely worthless, no matter what kind of drivers he uses..." 
 
So, what was Pham thinking? Consider that with all his apparent material wealth, he is still stuck with a room that is narrow relative to its length and relative to the listening distance. When forced to set up in a narrow space, one might be tempted to try placing the HF sources on the outside as Pham has done (I'm not saying its right); this, in the interest of greater perceived channel separation, as humans localize/locate HF more readily than LF.
 
Pham's original system (see earliest images) was vertically aligned, with only the HF driver off to the side. It looks like he went sideways with the MF horns when he started drinking the Goto Kool-Aid. I'd be willing to bet that future evolutions will have him adding more Goto hardware.
 
Goto drivers might sound excellent, but I sense that for some, Goto represents more than sound. In these cases, Goto is also filling a prescription and a crack in a foundation. I know such a phenomenon exists with other high-end/luxury products, and this is fine, unless we are talking about art or products that verge on art; here is where I might cringe.

jd*

Posted by AOK_Farmer on 12-22-2010
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From a shoppe that requires you to be a Fortune 500 CEO or a haute couture house owner to get in.

I dont know why you are trying to fit that system into a serious discussion. There are turntables where your feet go :-)

Actually I know why. How many *serious to the level of this blog's discussions* all horn systems from 50 Hz up are there in the world? Two dozen? Probably not.


Steve

Posted by Romy the Cat on 12-22-2010
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 jessie.dazzle wrote:
I do not interpret Pham's page to show that he is running more than just one horn system; what I see is an evolution of a system. It looks like, in its latest iteration (under the heading "System Update 9/29/10"), Pham has abandoned the Westrex/Lancing drivers as well as the wooden horns, both large and small, in favor of the Goto/ALE hardware. So to be clear, it seems he moved from Westrex/Lancing toward Goto/ALE. 

It is not the message that I got. His "System Update 9/29/10" is applicable for TT and it is not clear if he went from Westrex/Lancing to Goto/ALE version or in revised direction. My presumption is that he went from Goto/ALE to Westrex/Lancing as what kind person would voluntarily get rid of this big horn and replaces it with two laser-beaming Goto pipes? I agree that his sticking with JBL 1500AL driver in JBL 4344 enclosure, Fostex T500Mk2  and Mewon Ribbon TS01 is interesting. This is what playback journalism shall be all about – the patterns of preferences shall be recognized and the owner/designer shall comment on his rational. In the opposite side we have the typical 6-mooned idiocy as we have.

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