Martin Logan ESL Electromotion-No panel sound

[jmanny]

I recently purchased a pair of used ML ESL Electromotion speakers that unfortunately didn't come with power supplies. I purchased an off-brand power supplies from Amazon to use with these speakers. I plugged in the power supply to each speaker, the light on the back of the speakers turns on (blue), sound comes from the woofer at the bottom of the speaker, but sound doesn't seem to be coming from either panel. Both speaker are having the same issue. Does anybody have any ideas what could be the issue?

 

[Brad225]

Welcome manny. You should reach out to ML tech support with this issue. They are usually very responsive.

 

[StimpyWan]

The internal wiring harness on those speakers is pretty tight. Not much slack. You might want to check to make sure a wire didn't disconnect?

Also, with the woofers working OK, and the panels quiet, the ESL bias voltage boards might have failed. I had that happen on one of mine. A new board from ML fixed the issue.

Good luck.

 

[jmanny]

The internal wiring harness on those speakers is pretty tight. Not much slack. You might want to check to make sure a wire didn't disconnect?

Also, with the woofers working OK, and the panels quiet, the ESL bias voltage boards might have failed. I had that happen on one of mine. A new board from ML fixed the issue.

Good luck.

I reached out to ML support and they believe "replacing the internal power supplies as they are the only thing left that would keep just the panels from working." So I ordered 2 replacement internal power supplies ($95ea). I just found time to remove the panel to see if any wires came undone and the 3 wires connected to the panel are still attached. If you move the red wire a little with my finger, you can feel a little electric shock. But still no sound from the panel, just the woofer. This is my first experience with electrostatic speakers, when they're working properly, the full panel should be putting sound out right? Is there a warm up time or anything for the panel? Both speakers are in great shape, but both are having the same issue. I vacuumed both panels in case there was dust pile up, but unfortunately that didn't help. If you have any other methods you think would work, please let me know, I'll try anything

 

[jmanny]

Wait a minute, I think I'm getting sound out of the panel! The volume is way lower than it should be, especially compared to my other speakers. The sound doesn't seem to be coming from the full panel either. The sound is mostly coming from the top of the panel and towards the bottom only. Is this a sign that they need to be washed?

 

[jmanny]

The internal wiring harness on those speakers is pretty tight. Not much slack. You might want to check to make sure a wire didn't disconnect?

Also, with the woofers working OK, and the panels quiet, the ESL bias voltage boards might have failed. I had that happen on one of mine. A new board from ML fixed the issue.

Good luck.

The internal power supply was delivered today (ML said thats the same as a bias board), so I swapped it with one of the speakers. It honestly didn't really change anything. The woofer volume is about half the volume of my other speakers too. I see other parts inside the speaker cabinet, do you think it could be one of the other parts? I assume theres a crossover in there? Could that be the issue?

 

[StimpyWan]

The internal power supply was delivered today (ML said thats the same as a bias board), so I swapped it with one of the speakers. It honestly didn't really change anything. The woofer volume is about half the volume of my other speakers too. I see other parts inside the speaker cabinet, do you think it could be one of the other parts? I assume theres a crossover in there? Could that be the issue?

Internally, there's a small LED board, (attached to the input panel), the bias voltage board, and the crossover. The woofers connect directly to the crossover, so they'll play regardless of panel issues. The panels feed from the crossover, and the bias boards, resulting in 2 areas of potential issues. But, the crossovers are well built and less complex, and shouldn't fail. If new bias boards haven't helped, continue to ask advise of ML.

Good luck.

 

[jmanny]

Do you think it could be the audio transformer or the crossover causing the low volume issue, since the volume is really low from the subwoofer and the panels? I've tried to power the speakers with a Fosi V3 monoblock amp, a Denon avr-s740h, and an older pioneer vsx AVR and all had the same result. The ESLs are 4ohm speakers, but I've never had an issue powering 4ohm speakers on any speaker before. Im currently powering 2-ML Fx speakers (4ohm) for the rear and 2-ML Vanquish ceiling speakers (4ohm) with the Denon and they sound great. Do you think this is a matter of an ohm conflict?