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In the Forum: Horn-Loaded Speakers
In the Thread: New superlative horn build - ESD acoustic
Post Subject: OK, it is more clear now, thanks to you.Posted by Romy the Cat on: 5/14/2018
 martinshorn wrote:
Indeed you sound a little racist, but i think we all have our prejudice.  

I do not think that it is racist in any way or form. Racism is a prejudice against a race in my case it is prejudice and historical narrative against a country able/wiling to furnish a certain class of high-end products.

 martinshorn wrote:
I also listened to Cessaro, again this year, multiple times, and to cut the off-topic short: theyre no good. They lack all dynamics, colors, beauty. They have no faulty tonality or something obvious, theyre simply dead and unpleasant. I tried to share my thoughts with the main representative. He did not care, as all the other arrogant morones on the exhibition.
I have no interest to defend Cessaro and I in fact never heard them. There are zillions reasons why they might not sound good but it is not eliminate the fact that Cessaro were the first topologically-properly made horns.

 martinshorn wrote:
The dad is the sponsor, initiator and CEO. He had many horns, including Goto, Ale, etc. He was not pleased so asked his son to develop one.
His son is an engineer. As he got deeper into the topic, they spotted the need to do everything, from DAC down to the horn and driver and all inbetween.
Theyre doing DAC, preamp, poweramp, fieldcoil-current-unit, drivers and horns.
He gathered a team of developers, things took a route and so on.
Now as you throw names, youre actually throwing right direction, Sam Saye and Bruce Edgar are part of their team. He did design the horns, and theyre 1:1 according his supervision. The diaphragm are customized by Truextend which involves Saye as much as the field coil.
It is nice to know. Thanks for sharing the information.
 martinshorn wrote:
So first in line, the horns.  They stressed out that particularly the horn flares where not within the comfort zone of their own developer team. That triggered the recruitment of Bruce Edgar. The design is only his, and they took it 1:1.
I wonder how the relationship with Bruce was structured. I feel it is very important. If they used Bruce as a contractor who designed to them horns then they are not entitled to drum the Mr. Edgar’s name and promote Bruce and some kind of “founder”. If Bruce is the “shareholder" of the company and have ingoing participation in the company developed then it is fine but please let Bruce to vet  the marketing BS that they make publicly available and at present time their on-line presentation sound like they are clueless.

 martinshorn wrote:
Now Bruce Edgar advised to vary the horn shapes depending on their usage. He advised, not like LeCleach, to have one flare only, but rather use faster opening in the higher octaves, more narrow in the lower.The fast opening is supposed to be benefitial for the sound perception in heights. So the upper 3 are tractrix, with 3 different opening rates or t-factors. The higher the octave, the smaller the t-rate. The fundamental horn is non tractrix but exponential. Though, the t-rate is much higher. That lowers the Q of the horn, and us such, smoothenes the group delay, and together with crossover gives a lower order roll-off.
That is super intelligent and applaud Mr. Edgar for going in this direction.

 martinshorn wrote:
In the base, Bruce chose to use a 3 meter hyperbolic with even higher t-rate.
Indeed the roll-off balances nicely most room modes and boominess (i can confirm it was very dry and clean transient in the lows).
This “dry and clean transient in the lows” when we are talking about bass hos is something that I very much do not like in bass horns. It is VERY hard to get there but it is VERY none-musical. It is very impressive during demonstrations but in my view is very much annoying. Bass need to have fast transient but to be wet not dry. A dry bass does not provide a proper harmonic support to lover mid-range. This is the ugly bass that Goto, ALE and the rest of high-flax drivers produce. There is way to deal with it but I do not see folks are looking in this direction.

 martinshorn wrote:
Bruce Edgar decided to use the mouth and flare functions collaborating with the driver and crossover, shaping the final crossover Q's.
So, Bruce will be deciding and designing crossovers for them?
 martinshorn wrote:
Now, coming to the field coil, they had nice ideas.
They were not pleased with soft magnets.But also they dared to take the Goto apart to measure the flux. I guess no one did that before, Including Goto themselves. They found to have only 1.6 of the claimed 2.4. Funny enough...
That actually confirms the theory of a buddy i know who sais according to their material and geometry Goto cannot reach that high tesla.
Doesnt matter, Goto sounds nice, and thats what matters. 
But how to get real 2.4 tesla? 
So they got Sam on the boat, and just did hugely oversized field coils.
The saturation clips at 2.2 tesla. 
I absolutely do not support this way of thinking and I think to peruse higher tesla number is very much foolish idea. Why one need to go 2.4T? The T number is relevant ONLY in context of performance of a specific diaphragm, a specific suspension type, a specific type of loading, a specific driver range etc… There is absolutely no need to get max T from an abstract driver.
 martinshorn wrote:
What they do, they have one big device that looks like an amp, that has one individual circuit per driver, so 10 in total (2x5), for the field coils. Its a current-driven dc-amp. That makes the voltage variable, but constant current. By that the warmup is eliminated. The transients are are back to full attack. Theres even an eddy-current flux sensor integrated with a feedback-loop to the dc-amp that compensates the flux-modulation. This really kills even the tiniest motor-distortion possibly left. The next problem in line then was the temperature in this design. The coils did just melt down. Also they didnt fit the magnet around the phase-plug, and the throat-tunnel became very long which was coloring sound.This was solved by 2 steps, one is described later within the phase-plug part.The other explains why the drivers are so big: theyre wrapped in coolers. That covers for most circumstances.
Ok, the invested in some field-coil investigation, this is nice. Probably they bought out or licensed the Sam Saye’s idea, or perhaps brought him aboard. Indeed, there is some complexity to saturate electro-magnetic force at a very focusing pint and to keep the things cool enough in order do not introduce dynamic “sinking” as the field-coil getting hot. One way to do so do not go after crazy amount of Teslas.  Different companies resolve the problem differently, I have no idea why no one go for liquid cooling, it would be so simple and so effective.  The variable voltage at electro-magnet makes me very uncomfortable.  If they still experimenting with it then it is fine but at the final product if much not be there.

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