I too am very interested in this possibility.
Sorry for the long preamble, but it is salient...
In my motion control work, PID loop phase margin is an essential issue for some of the loads I have to move. As such, I have to worry about the overall system response with frequency.
One aspect never considered in the motion control world is the nonlinear magnetic behaviour of the the motors. When a motor is being fought, the resultant spring constant of the motor changes, loose when not pushed, tighter when fought. This impacts the Bode plot of the system such that I can tune a system in a position where the forces are maximum, and when I open the device to a far less force position, lose all phase margin and oscillation ensues...
For an ESL, the force applied to the membrane is dependent on the voltage, so I would think the response plot would change if that voltage changes, as the overall spring constant will be bias voltage dependent..
jn
Yah huh.....kindly makes one wonder.
Well I surely appreciate you going out of your way to explain what could possibly be the cause of differences in sound instead of just hopping on board the ‘your crazy’ train (Ozzy pun intended!)
I think 1audio mentioned monster xp being equivalent to 18awg and that possibly switching to 14awg was part of the difference, in a direct eyeball comparison it has as much or maybe even a little more heft to it than 14awg (after removing all the extra plastic and center tube)
And as stated by Hans, if relating what I’m hearing (even if it goes against the grain) might initiate some deeper digging and possible verification I’ll take the abuse!
Last edited:
Of course I have. The Dean of the medical school was very keen on it around the time I retired from Stanford. I warned people about it, but they wanted to believe in it. None the less, I think there is probably some real data about audibility in anecdotal reports, the big problem that I don't know how to overcome is how to extract useful information from it.
Last edited:
As long as the claims does not show attempts of deception, blatant lies or otherwise. In my book, deception to the public for profit is crime.
You can reproduce them but I'm willing to bet they won't look pretty by the time they get to your ears.
Do any scientists actually do that? I really hope they have better things to do. Mind you, if they are getting paid for it.........
In fact an ESL speaker, being a capactor, is driven by a current because a cap’s impedance goes down with 6dB/oct which would cause FR to go up with the same slope when driven from a voltage.
A transformer in the audio signal, having high ohmic resistors in series with the differential secondary site, drives both stators as current sources.
No bias voltage involved at all.
But as every cap, there is a point in the FR where the impedance goes up because of series inductance etc.
But also the differential tranformers have there limits in the HF range.
I have no idea which of the two have the dominant effect of the hf roll off of the ESL, but I don’t see any reason why the HV unit who’s only function is to keep the membrane charged with a constant value could have any influence on HF behaviour.
Hans
Odd. You say no bias voltage, but then say the HV unit is used to keep the membrane charged...
Aren't we saying the same thing? I consider "the membrane charged" to be bias voltage.
jn
Yes, that was the hard lesson Re-learned. They took a rare chance and .... But he was really sharp... just no experience... I am sure he wasnt the only casualty.
-Richard
Last edited:
Just having read reviews on Acourate and Audiolense DSP software.
I’m positively surprised how much can be done nowadays for XO design and for speaker correction in amplitude and GD.
Correcting FIR filter coefficients created by such software can be fully integrated into JRiver or Foobar.
Very impressive.
Hans
I’m positively surprised how much can be done nowadays for XO design and for speaker correction in amplitude and GD.
Correcting FIR filter coefficients created by such software can be fully integrated into JRiver or Foobar.
Very impressive.
Hans
Maybe this would help?
something similar to this...
But I would bet a dollar it has leakage issues somewhere.
JBL M2 Audiolense Digital Crossovers w/Subs -->
JBL M2 Audiolense Digital Crossovers w/Subs | Audio Science Review (ASR) Forum
" A note about time domain. I've read Sound Reproduction. I'm aware of the paucity of science that show any advantage to time aligned drivers compared to typical minimum phase implementation. I accept the lack of research in this area. BUT, I can speak from my own experience. I've time aligned many different speakers in my room and have always heard a big improvement in 3D image and image accuracy. I think some audiophiles have morphed Toole comments about the lack of research in this area into proof that driver time alignment cannot be perceived. That's simply not the case. There's just not enough research in this area and more needs to be done, IMO."
-RNM
Last edited:
So the last ( @ JN ) has nothing to do with "audible sound reproduction".
Same for frequency response curves, as the sound pressure has nothing to share with sound. Oh, yes, it's the magnitude of a vector is space...
Last edited:
It is always an interesting question if anecdotal evidence is more like real data or more equivalent to noise.
Paul Frindle had a reasonable stance on that; starting with his own opinion as a statement and further explanation why (Sub-Headline was "Open minded Approach"):
(Paul Frindle; Are we Measuring the Right Things? Artefact Audibility Versus Measurements; THE MEASURE OF AUDIO - AES UK CONFERENCE; 1997, MOA-05,)
Overall IMO a very reasonable approach; as said before, the audio field is no exception it is just the same as always, you have to sort out the people who you are willing to trust more in their judgements. Nobody is perfect, but usually it works.
Paul Frindle had a reasonable stance on that; starting with his own opinion as a statement and further explanation why (Sub-Headline was "Open minded Approach"):
(Paul Frindle; Are we Measuring the Right Things? Artefact Audibility Versus Measurements; THE MEASURE OF AUDIO - AES UK CONFERENCE; 1997, MOA-05,)
Overall IMO a very reasonable approach; as said before, the audio field is no exception it is just the same as always, you have to sort out the people who you are willing to trust more in their judgements. Nobody is perfect, but usually it works.
No bias voltage on the audio signal, but a constant charge on the membrane which of course means a constant HV bias voltage.
Since this charge or bias if you like has a constant value, it has no direct effect on FR in a current driven topology and also AC mains voltage creating the HV is unlikely to have an effect on HF roll off.
As I have tried to explain, this roll off can only be caused by ESR and ESL of the electrostatic element and/or the limited BW of the audio transformer.
Hans
I can confirm that XP is 18 AWG (counting strands on this stuff is no picnic). The appearance was tuned to look "Monstrous". Be sure you are not confusing XP with OMC which is closer to 12 AWG but looks similar. Its pretty academic since Monster is pretty much out of the cable business (and be really cautious of the Monster from Walmart).
I was speaking about the hv bias aspect, not biasing of the audio signal.. As I said, the resultant force on the membrane will be altered by the hv supply level, so that was what I was talking about.
And while the capacitor is indeed current fed as you say, it is not the current that causes the membrane force, it is the relative voltage of the membrane in the e field, the current only charges the capacitance.
This discussion is almost exactly the same as an electrodynamic where the magnet strength is varied by changing the coil current.
I can indeed see the possibility of a variation of the ESR of the membrane caused by bias voltage change, but assume it would be quite small if the conversion efficiency is low.
Keep in mind, I call the HV field the membrane is within, the "bias field". Others may have a different name for it, but it's the same thing. The dark matter detector people use an entirely different nomenclature for their 5 and 10 megavolt thingies. The various names can get confusing at times.
jn
Last edited:
Actually, it does.
As I said, the preamble detailed how the amplitude and phase response of a magnetic field driven system will change when the force required of the driving device increases. (or if the magnetic field of the driver is changed in intensity)
So does an ESL if the HV field voltage is changed..
The only question remaining is....has anybody actually measured the frequency response of an ESL when the HV supply value is changed, precisely what Richard mentioned.
jn
- Status
- Not open for further replies.