MartinLogan Speakers

Through some 'friends of friends' turns out that I have come to know Ron Logan Sutherland's ex-wife (Barbara) and her current husband (Kevin), as they had and amp that needed fixing. Through conversation she mentioned who her ex husband was, and I thought that was pretty damn cool.

I fixed the amp, and am preparing to get it back to them. Barbara is still good friends with Ron, who is/was the co-founder of MartinLogan speakers. Of course, I know enough about the company to know that he left years ago to start his own electronics firm, but she has offered to take a trip out to his place with me along, and meet the guy. I'd love to do so, but I don't really know a huge amount about E-static speakers to ask any real intelligent questions.

So maybe you speaker guys can prime the pump here...I don't want to go out there looking like a doof (which, of course, is what I really am ). Got a few 'Q's' that I might ask the gentleman to make it look like I know something about electrostats?
 
Since you asked...

First of all he may be more interested in talking about his amps than his long-ago speaker affiliation. I'm not sure what his original function was at ML (besides co-founding and donating his middle name). But anyway, let's try:

What were the biggest factors in ML’s design to prevent arcing and increase reliability? The decision to eliminate deep bass from ML designs must certainly have been one of them.

What coating was used on the diaphragm and was it applied to both sides? (may be a trade secret, and the current coating may be different than what it was when he was at ML). What was the ohm/square resistance goal for the diaphragm? Did they do extensive testing in various humidity conditions and elevations (pressures)?

What approximate panel resonant frequencies were their goals? Did they set resonance frequencies so that rising low frequency response counteracted increasing dipole cancellation?

How did they stretch the diaphragm only vertically for their curvilinear design, without causing much stretching and cave-in in the lateral direction? Did they heat shrink or mechanically stretch or both? What device or jig did they use?

The stators receive very high push-pull audio voltages from a low enough impedance secondary to present a shock hazard if someone were to contact both front and back side simultaneously (true of all ESLs), with music playing of course. ML’s stators appear to be coated with a carbon-loaded substance and must be slightly conductive to preserve the electric field in the air gap. How did they ensure no shock risk with this coating? Was it tough to balance shock insulation with not stealing the electric field from the air gap? What if stators were to be scratched, exposing the metal within (from a safety/liability concern)?

I could go on…but I won’t. If he’s patient enough to answer these, I’ll be pleasantly surprised, and thanks for asking!
 
Brian Beck said:
Since you asked...

First of all he may be more interested in talking about his amps than his long-ago speaker affiliation. I'm not sure what his original function was at ML (besides co-founding and donating his middle name). But anyway, let's try:

What were the biggest factors in ML’s design to prevent arcing and increase reliability? The decision to eliminate deep bass from ML designs must certainly have been one of them.

What coating was used on the diaphragm and was it applied to both sides? (may be a trade secret, and the current coating may be different than what it was when he was at ML). What was the ohm/square resistance goal for the diaphragm? Did they do extensive testing in various humidity conditions and elevations (pressures)?

What approximate panel resonant frequencies were their goals? Did they set resonance frequencies so that rising low frequency response counteracted increasing dipole cancellation?

How did they stretch the diaphragm only vertically for their curvilinear design, without causing much stretching and cave-in in the lateral direction? Did they heat shrink or mechanically stretch or both? What device or jig did they use?

The stators receive very high push-pull audio voltages from a low enough impedance secondary to present a shock hazard if someone were to contact both front and back side simultaneously (true of all ESLs), with music playing of course. ML’s stators appear to be coated with a carbon-loaded substance and must be slightly conductive to preserve the electric field in the air gap. How did they ensure no shock risk with this coating? Was it tough to balance shock insulation with not stealing the electric field from the air gap? What if stators were to be scratched, exposing the metal within (from a safety/liability concern)?

I could go on…but I won’t. If he’s patient enough to answer these, I’ll be pleasantly surprised, and thanks for asking!
Some of your questions are trade secrets. I wonder also have they make the stators curved.

BTW: I have a pair of Martin Logan SL3 and am quite happy with them altough some paint has cracked up and is gone on top of the bass cabinet :bawling:

Small objection would be a bit soft bass but it goes down real deep, below 30 Hz I should think.