At my current level of understanding of Audio reproduction i have to conclude that the optimum system would have to consist of the following:
ESL section covering approximately 300 hz - 20 khz. this can be either a single curved section or a 2-way with a curved HF driver and flat LF driver. some sort of foam attenuation can be used to attenuate the backwave.
Dipole Array section covering approximately 50 hz - 300 hz.
Multiple Distributed Sealed Subwoofers 50 hz and down.
the 50 hz crossover point to subs is approximate. in actuality it would be about 50% higher than the frequency at which room pressurization starts so room dependent.
So question is - aside from size, cost and the obvious need for at least three amplifiers - can you give me a reason why this wouldn't be optimal ?
of course anybody else who thinks they know why this wouldn't work is welcome to share your opinion as well.
ESL section covering approximately 300 hz - 20 khz. this can be either a single curved section or a 2-way with a curved HF driver and flat LF driver. some sort of foam attenuation can be used to attenuate the backwave.
An externally hosted image should be here but it was not working when we last tested it.
Dipole Array section covering approximately 50 hz - 300 hz.
An externally hosted image should be here but it was not working when we last tested it.
Multiple Distributed Sealed Subwoofers 50 hz and down.
the 50 hz crossover point to subs is approximate. in actuality it would be about 50% higher than the frequency at which room pressurization starts so room dependent.
So question is - aside from size, cost and the obvious need for at least three amplifiers - can you give me a reason why this wouldn't be optimal ?
of course anybody else who thinks they know why this wouldn't work is welcome to share your opinion as well.
The premise of this thread is rather ludicrous. Why should these gentlemen respond when it's obvious you either haven't read their work, OR disagree with the fundamentals of it?
what does their work have to do with this ?
just because neither of them are involved with ESLs for example doesn't mean they can't appreciate the advantages of this technology. most likely they simply find it boring because it needs little improvement.
i understand that working with horns is very exciting because so many things can go wrong. but i don't want anything to go wrong in MY system. i also understand that building a transient perfect 3-way using passive components may be fun too but an ESL doesn't need a crossover to begin with.
i am asking John K and Geddes because i trust their judgement in general, not because i am interested in any particular niche technology that they happened to be involved with. i trust that, unlike you, they would be open minded enough to consider ideas outside their field.
besides - why would i ask Linkwitz whether dipoles are the way to go ? that would be retarded.
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An ESL will always have the problem that the waveform from the ends will arrive at a time delay greater than the threshold of time delay detection by humans. They will therefore always have an associated time smear thru-out their bandwidth.
dave
dave
you're speaking as if there are two distinct waveforms here rather than a continuum. this is not an array but a panel - i don't think your logic applies here.
It matters not whether it is a line array or its limit, a continuum. The waveform from the top of the panel or the bottom of the panel takes longer to get to your ear than the stuff from the middle -- at least in any but a HUGE room with a listening position in the far-field.
dave
dave
so tell me Dave - doesn't that mean that high frequencies must be almost completely GONE due to all the cancellation from time delay ?
😉
this isn't something easy for humans to understand. even i have to think about stuff like this to understand it. the good news is that his brilliance ( me ) is willing to help humans in this endeavor.
ps: i am taking a nap ...
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Borat,
Planet10 is correct that a linesource will always experience time smear. However, I do not believe the effect is due to cancellation or because the sound radiated from the ends reaches your ears later. Indeed, the panel launches a wave. A cylindrical wave to be precise. These wavefronts are inherently dispersive.
HOWEVER, due to the way the panel interacts with the fluid, the panel launches dispersive waves which experience group delay. Higher frequencies travel faster than lower frequencies (ie phase distortion). This is why time smear is observed in linesources. It is dictated by the size of the radiating surface and is unavoidable. It is also non-linear, so electronic equalization is not an option.
The only non-dispersive wave function (transient perfect) is the sphere and an ESL definitely doesn't launch a spherical wave.
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There is no 6 microsecond threshold for time distortions which arrive equally at both ears. The test you keep referring to determined that threshold by messing up ONE channel of a stereo set not both.
Statistically it does... but you still have sound from the ends reaching the ear... can be seen in both the FR & the impulse
(images courtesy of sterophile.com)
If one does th math the delay from top & bottom is much larger than the human detection threshold (attached).
This isn't saying that ESLs don't have their benefits, but because of this flawe they can never be optimum.
dave
dave
Attachments
Borat,
You could go and read this thread.
http://www.diyaudio.com/forums/planars-exotics/148963-magneplanars-enabl.html
Tis an experiment easy to perform. A cheap and completely removable treatment form that works on Maggies to make the bass clear and deep, the mids majestic and hi's without any hint of time smear. Or, you can just go ahead and do what you were going to do anyway.
With that much woofer surface you could also make those OB, with a John K spec'd cardioid open enclosure for floor and ceiling. Bass would be mountain sized indeed!
Bud
You could go and read this thread.
http://www.diyaudio.com/forums/planars-exotics/148963-magneplanars-enabl.html
Tis an experiment easy to perform. A cheap and completely removable treatment form that works on Maggies to make the bass clear and deep, the mids majestic and hi's without any hint of time smear. Or, you can just go ahead and do what you were going to do anyway.
With that much woofer surface you could also make those OB, with a John K spec'd cardioid open enclosure for floor and ceiling. Bass would be mountain sized indeed!
Bud
Statistically it does... but you still have sound from the ends reaching the ear... can be seen in both the FR & the impulse
(images courtesy of sterophile.com)
If one does th math the delay from top & bottom is much larger than the human detection threshold (attached).
This isn't saying that ESLs don't have their benefits, but because of this flawe they can never be optimum.
dave
dave
that impulse repsonse looks much better than most speakers would even mounted in infinite baffle.
did you somehow figure out how to build diffractionless speakers ? because unless you're doing this:
http://www.diy-av.net/forum/viewtopic.php?f=28&t=367
there is still going to be plenty of delayed energy.
what is this enabl of yours ?
why don't you make a wikipedia article for it to make life easier for Borat.
I tend to agree. Its like asking "When did you stop beating your wife?"
To answer is to accept the premise and asumptions. I don't.
I was in a discussion just tonight about SL Orions. The premise of the study was stated and I was asked if I was interested in being involved. "Since I don't accept the premise, No."
Appears to be a loss less method for eliminating resonance nodes that steer what should be a minimum phase, flat wave emitter, into something with lobes, null zones and resonances.
Bud
ok, so where is your contempt towards dipoles documented ? i would like to look at the reasoning.
Link !
Also ...
where can i listen to Orions ? It's the first time i hear somebody say that Orion is no good. i had to listen to Martin Logans because Romy the Cat claimed that they sounded "horrible". now i need to know just how "horrible" Orions are 🙂
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I really wish "every" thread would not end up contaminated by Enable nonsense.
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Large, finite panel radiators are not line sources and will beam as the frequency rises:
Starting at the outer most response, 250 Hz, 500, 1000, 2000, 4000.
{edit} the panel is 1' wide, 4' tall. Plots are for 4M away.
However, true infinite line sources which launch cylindrical wave can not be transient perfect. Only plane wave and spherical waves can preserve wave form. This has nothing to do with how the wave is launched form the source, but rather the form of the solution to the wave equation. The solution for cylindrical waves involved Bessel functions and, as a result, the propagation of an impulse in a cylindrical wave develops oscillatory tails.
As for want is optimum. What ever floats your boat.
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Large, finite panel radiators are not line sources and will beam as the frequency rises:
Starting at the outer most response, 250 Hz, 500, 1000, 2000, 4000.
{edit} the panel is 1' wide, 4' tall. Plots are for 4M away.
However, true infinite line sources which launch cylindrical wave can not be transient perfect. Only plane wave and spherical waves can preserve wave form. This has nothing to do with how the wave is launched form the source, but rather the form of the solution to the wave equation. The solution for cylindrical waves involved Bessel functions and, as a result, the propagation of an impulse in a cylindrical wave develops oscillatory tails.
As for want is optimum. What ever floats your boat.
thanks for recognizing that this thread is not about wife beating 🙂
4 x 1 foot panel is a reasonable size. and at 4 khz it does look like a laser in that plot. my question is - would that situation be somewhat improved with a curved panel like the one Martin Logan in the picture i posted uses ?
i obviously don't know much about wave equations so let's just assume that what you said is true. would it be possible to ( for a given listening position ) restore the impulse response using FIR processing ? and if so how big of a "sweet spot" could one expect to have ?
fair enough.
EDIT: also, can i assume that you approve of the dipole midbass and distributed sealed subs ?
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Well put.
I wish the EnABL discussion can be done in that thread as well because the guys that support it do not have any data to show.
I wish the EnABL discussion can be done in that thread as well because the guys that support it do not have any data to show.
ESL designs do have an advantage that result in some good audible qualities, but the larger these get, they also start acting with some modal vibrations that smear the sound.
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