I got what I thought was a great deal on a used pair of EM ESL speakers. Unfortunately for me, while the seller setup the speakers and I got to listen to them, my naked ear did not notice a problem at the time. Definitely learned a lesson here and will be more prepared in the future when buying used speakers.
After bringing them home, I noticed one was significantly louder than the other. After doing some troubleshooting with ML (who responded very quickly with detailed steps, which was great), we determined that one of them had a bad panel and I was quoted $700 plus shipping for a replacement.
One thing that I did notice is that the panel wasn't just quieter than the other one, it actually sounded very different using the test tone on my receiver, even with the +10db correction it gave over the other panel. I suspect that the panel is dead above ~800hz based on these correction results:

My plan now is to check the actual solder joints on the panel itself, but if anyone has any tips besides vacuuming/cleaning them in a shower (I have tried both!) it would be greatly appreciated. Also, if I do ultimately need to replace the panel, is there anywhere I can go besides ML that may have it cheaper?
After bringing them home, I noticed one was significantly louder than the other. After doing some troubleshooting with ML (who responded very quickly with detailed steps, which was great), we determined that one of them had a bad panel and I was quoted $700 plus shipping for a replacement.
One thing that I did notice is that the panel wasn't just quieter than the other one, it actually sounded very different using the test tone on my receiver, even with the +10db correction it gave over the other panel. I suspect that the panel is dead above ~800hz based on these correction results:

My plan now is to check the actual solder joints on the panel itself, but if anyone has any tips besides vacuuming/cleaning them in a shower (I have tried both!) it would be greatly appreciated. Also, if I do ultimately need to replace the panel, is there anywhere I can go besides ML that may have it cheaper?