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In the Forum: Horn-Loaded Speakers
In the Thread: New superlative horn build - ESD acoustic
Post Subject: Ok, Let gig it.Posted by Romy the Cat on: 5/14/2018
 martinshorn wrote:
So what was next...
They build the DAC, patented the clock... ok.
They build their own preamp. Fully descrete class-a balanced, john curl wouldnt do it differently. Nice. Low and adjustable gain - very nice. Constant impedance step attenuator - my favorite!
So they know how to do it.
 
The amps are silicium, not for the SET fans. But theyre all fully active. 5 mono amps per side. A total of 10 amps running in their demonstration. Pure class A, god that was hot in the room !
Well, theyre running all on a single ended MOSfet with hi bias. Nice topology! Heard, had and compared such at home... sounds pretty much like tubes.
They did not go for tubes becoz of SNR. The FETs could have way lower noise by design. Sounds reasonable. For 110dB sensitivity speakers too. Im sure though some caps couldve lowered the last dc-noise further - just no one likes caps for no reason...      Now my favorite part: The active crossover device, running prior to the amps, is very flexible. 
The steepness is variable, the frequency too. And the speaker is designed to make a difference. 
The 8" - 4" - 3" - 2" cones or respectively the more relevant here 4" - 2" - 1" throats together with different horn shapes all have different beamwidth.Now for a lively room, you can just set all XO higher.In a dry environment you can put them all down.The lower the steeper, it also influences the lobing and so on.The system will be installed incl. voicing service.I know everyone can do the same but... Not if you dont care to have such continuous proportional size steps. And most of all: the beryl + hixcursion gives way higher bandwidth (±6 octaves) than normal horns (>2 octaves).
Funny enough, they arrived some days earlier but not the speakers.They got not time for proper voicing prior to the exhibition.So the second day i came it developed further. They had to make it in the evening between the days.It was really better the other day. 
   
Wow, a great effort and very commendable.  The 5 way, filly active multi-amped with own smart drivers and own smart horns. Indeed, it is very noble. I do wish they make this site as presentable as the objective to make the playback. So far reading the site they presented themselves as Morons, they need to change it. 
 
Let go with some looking deeper. They claim that they have 100Hz out of midbass horn and 20hz out of bass horn. At the picture I see no more than 150Hz and 70Hz. The EQ will help of you have own amps and your drivers can handle a lot of excursion but the would make OK lower response for juts little bit, to get a full octave or two by EQ is to make bass kind of ugly. bass They would do much better to claim 40-50Hz out of bass horn and then to introduce a complimentary LF section. I am sure they will do it eventually.  
 
It does look like Bruce keep consulting them. There is no way a marketing people would turn the horns to the wall. Bruce knows that direct radiation from the horn like this would sound like sewer belching and he pointed the horn to the wall letting the bass to “developed” and do some phase randomizing.  In interactive but the only appropriate gutsy move, I am sure that it was Mr. Edgar move. Regarding the martinshorn exuberance, sorry Josh, with all respect I do not invest a lot of credibility in this case about the sound from the system under discussion. With the horns like this you should have a very well defined resonance if the very prominent bend. With the high magnetic force drivers and SS amplification with higher dumping factor they will not be able to smear the resonance and it should be VERY auditable. Add to this the EQ. Ehhh, it should be very brutal. This specific configuration when the horns have no room to develop the LF pressure and experience a huge acoustic feedback from the wall, and considering the very dramatic bend in the horn the bass should sound like a barrel, literally. Can you imagine what kind throat reactance the horn has with that amount of acoustic feedback to the driver. You Josh described the fine moments of the drivers design and fine super light diaphragms in a sexy magnetic environment but you were listening the horns with literally jack hammers ion the mouth and you report a fine performance. Sorry, man I do not buy it.
 
Design wise there is one moment that I feel is not exposed but I would like do not let it to slide. Josh you said:  “Now my favorite part: The active crossover device, running prior to the amps, is very flexible. The steepness is variable, the frequency too.” Hm, the steepness crossover point? I am the only one who scare to hear it? First of all why the hell people need a variable crossover point? Second: as the people turn the variable crossover point (steepness!!!) then how they realign the timing?  The whole idea of timing in this playback is questionable and continentally left aside of presentation. I have a feeling that if they are serious and since they own DAC and do fully active then they can run 5 DACS and do delay in DACs. This would be very elegant but the notion of steepness crossover point kill it. If it would be stepped then it might be calibrated at DAC level but if it is steepness then it is end of everything. Hold on, I need to say that IF they run a feedback back to the DACs and steepnessly alter the delays in a DACs in accordance to crossover point then I will be the first who throw a standing ovation but I do not think they would go for it. I also do not feel that it would be necessary as no one need a variable crossover points. 
 
The video at your tube give some idea wheat is going in the room. It is started at 3:20 but worth to hear other rooms to get idea how the phone that did recording made the recordings.

   

Rgs, Romy the Cat

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