Of course, even Renesas conceded and special package a few pieces of the 2SJ162 in TO264 rather than argue with you.
Good catch, that would be 2SK1530/2SJ201 from Toshiba.
2SK1530/2SJ162 are the lateral mosfets from Renesas. I used 3x this pair in the PGP amp, with the Hawksford error correction output stage.
My tricks to raise the hardness of the horns.
- Choose your motor carefully and if possible, check it (with diamond suspensions, the slightest decentrations of the voice coil is catastrophic)
- Prefer circular horns, spherical waves. Le clearc'h ( or similar). These are the only ones I know that do not modify the shape of the impedance curve on their testing tube.
- The pavilion must be devoid of any resonance. Prefer solid, heavy wood.
- Linearize the impedance curve. (LC + RLC)
- Linearize the response curve. It must be a strait line, slightly descending.
- Use a passive attenuator to have the greatest possible serie resistance (compression motors like to be driven in current).
- Choose a cutoff frequency at least one octave above the resonance and the horn cutoff.
- Cross the speakers towards a point in front of the listener, so that the membrane is not visible to the listener.
- Don't try to go too high in frequency. 16kHz is ok.
The dynamics on the attacks and the fast damping are preserved, the hardness and the effects of reedy pinching suppressed. A very natural restitution is possible (all those Youtube enclosures are, indeed, disagreeable on some instruments). It remains nevertheless very analytical and focused, which does not please everyone and not in the direction of "easy listening".
Just my two cents, but years of experiments.
- Choose your motor carefully and if possible, check it (with diamond suspensions, the slightest decentrations of the voice coil is catastrophic)
- Prefer circular horns, spherical waves. Le clearc'h ( or similar). These are the only ones I know that do not modify the shape of the impedance curve on their testing tube.
- The pavilion must be devoid of any resonance. Prefer solid, heavy wood.
- Linearize the impedance curve. (LC + RLC)
- Linearize the response curve. It must be a strait line, slightly descending.
- Use a passive attenuator to have the greatest possible serie resistance (compression motors like to be driven in current).
- Choose a cutoff frequency at least one octave above the resonance and the horn cutoff.
- Cross the speakers towards a point in front of the listener, so that the membrane is not visible to the listener.
- Don't try to go too high in frequency. 16kHz is ok.
The dynamics on the attacks and the fast damping are preserved, the hardness and the effects of reedy pinching suppressed. A very natural restitution is possible (all those Youtube enclosures are, indeed, disagreeable on some instruments). It remains nevertheless very analytical and focused, which does not please everyone and not in the direction of "easy listening".
Just my two cents, but years of experiments.
Of course, all waves are spherical, because the speed of sound is constant. Because this is inconvenient, flat wavefront approximations have prospered, largely destroying the reputation of horns in general. With modern computing capability step-wise approximation to ideal horn dimensions is trivial, but the PR damage is done.
My father made two different methods to attack the computation. The first, in 1982, was a successive approximation followed by error calculation and correction, 500 steps, to be able to be run on the fancy new programmable calculator of the time. The second, after I'd recalled this and tried to discover what he was doing, was a geometric solution a la Huygen. Which is pretty much JML'C. I've posted these here:Method for contoured horn wavefronts similar to JMLC
But they're rough going for non-ME's.
And as I today turn the same age of his death, I thought I should mention it. He actually designed turbine blades, for big Navy ships and for compressing the entire big-inch line to recover the Helium. Among other things. We can never beat our fathers at pool.
All good fortune,
Chris
My father made two different methods to attack the computation. The first, in 1982, was a successive approximation followed by error calculation and correction, 500 steps, to be able to be run on the fancy new programmable calculator of the time. The second, after I'd recalled this and tried to discover what he was doing, was a geometric solution a la Huygen. Which is pretty much JML'C. I've posted these here:Method for contoured horn wavefronts similar to JMLC
But they're rough going for non-ME's.
And as I today turn the same age of his death, I thought I should mention it. He actually designed turbine blades, for big Navy ships and for compressing the entire big-inch line to recover the Helium. Among other things. We can never beat our fathers at pool.
All good fortune,
Chris
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Some of the best imaging I’ve heard was from big horns.
But, as you seem to say, you have to really know your stuff because they can sound boxy (to my ears) - but get it right and they have a certain magic. It also has to be said they don’t suit all music - maybe others have similar experiences. Small jazz combos, opera and orchestral music. I don’t think you could ever classify them as accurate.
There was that famous quote, by M.Twain, I think:
“Never argue with an idiot. They will drag you down to their level and beat you with experience.”
Horns have the advantages and disadvantages of large area radiators: the large radiating area gives comparatively low time modulation because of the smaller necessary diaphragm movement, but also makes integration with other drivers (especially of course the tweeter, if needed) more difficult.
Paul Klipsch made a case for strong correlation between low distortion and high "efficiency". This is actually true if "efficiency" is defined in terms of conversion efficiency. Large surface area drivers like electrostatics are themselves highly conversion efficient but burdened by "external" parasitic capacitance needing its pound of flesh.
What does this mean to amplifier design? What would amplifiers look like if they only needed to make peaks of +10dBW?
All the best fortune,
Chris
Paul Klipsch made a case for strong correlation between low distortion and high "efficiency". This is actually true if "efficiency" is defined in terms of conversion efficiency. Large surface area drivers like electrostatics are themselves highly conversion efficient but burdened by "external" parasitic capacitance needing its pound of flesh.
What does this mean to amplifier design? What would amplifiers look like if they only needed to make peaks of +10dBW?
All the best fortune,
Chris
Horns have quite a few challenges, one of them is the impedance mismatch between diaphragm/phase plug/throat/mouth, causing multiple reflexions before the sound wave hits free air. I've previously mentioned an AES paper by JVC, here's the relevant page in the "Loudspeakers - An Anthology".
The presentation was even more spectacular thanks to the video, but I'm afraid the tape is lost forever.
The presentation was even more spectacular thanks to the video, but I'm afraid the tape is lost forever.
Attachments
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Yes, sadly this is the case for all of the conventional commercial horns from the last half century. It's given the whole idea such a black eye that, combined with being old-fashioned, it's "sleeps with the fishes" dead. Not wrong, but dead anyway. Leave the gun, bring the cannolis.
All good fortune,
Chris
All good fortune,
Chris
How would you define better and what measurement do you make on the acoustic output to confirm?
I really don't understand why people are so obsessed from horns.
For accurate treble, there are easier ways, the efficiency in the middle
is not really needed in a home environment and really low bass does
not work because you can't get a mouth size big enough.
In a former life, a friend of mine solved the mouth size problem for a club
with a construction made from bricks. You could walk into the opening.
That thing was soon retired because of complaints in the neighbourhood.
Wow.
For accurate treble, there are easier ways, the efficiency in the middle
is not really needed in a home environment and really low bass does
not work because you can't get a mouth size big enough.
In a former life, a friend of mine solved the mouth size problem for a club
with a construction made from bricks. You could walk into the opening.
That thing was soon retired because of complaints in the neighbourhood.
Wow.
Because JAM and Mark were talking about commercial products, the mythical 'successful high end product' with an inference that merely designing something with sterling performance was not enough. I was pointing out that high end audio is as much sold on the dream as the actual sound quality.
I wouldn't call an M5 fat or wallowy....
My reference point for a car you 'drive' is the Caterham I used to own. compared to that the M5 is a computer controlled blancmange you aim at things.
I don't know what value YouTube videos can have, so I asked, not much response but he appeared to have some experience. YouTube system demos
Nope this was based on TT saying that it was Sterile. This gets thrown around, mostly for very accurate amplifiers and I've not seen a credible reason for it so have to assume that some people don't like total accuracy. Certainly Nelson wins a lot of awards for a carefully crafted signature.
But for me if someone says 'sterile' I , rightly or wrongly, assume its actually exceedingly transparent and that't not what they were looking for. Which is fine, each to their own, vive la difference etc.
Diaphragm axial movement causes an inherent time modulation, a real distortion with real new frequency components generated. The only solution is larger (effective) surface area, to generate a specific SPL with less diaphragm axial motion. Horns are one design, a compromise to increase effective diaphragm size. Of course there are others with their own individual compromises. Direct-driven panels have their motor issues, and so it goes.
I might turn the argument back as: Why are people so obsessed with vanishingly small distortions in electronics when they're to drive such high distortion transducers? The best speakers are more distorted, even if only considered in the much simplified dimentionless arena of an amplifier, than even a reviled SET no-feedback valve amplifier. I guess amplifiers are just sexier.
Always the best fortune,
Chris
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I have challenged those here to come up with a better design -- at least lower distortion. I added a couple ideas which were amp based to lower speaker distortion. But only got some L measurments so far from JN. I think the basic design of dynamic drivers is good but has reached it's limit and something fresh and out of the Box thinking is needed.
THx-RNMarsh
THx-RNMarsh
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