I’ve been waiting for someone much more knowledgeable than me to jump in, but here are my quasi-neophyte opinions (worth what you pay 😉 )
The “cross over” you see I suspect is actually the linear power supply that applies the bias across the electrodes. The fact that you hear no difference in volume between the speaker plugged in or not and that the knobs don’t do anything suggests the electrodes are not getting voltage–maybe a blown fuse? I’m not sure what to make of the fact that you hear an effect of the brilliance knob–it seems it wouldn’t work either if the electrodes are not powered up?
I’d call Sound Lab and see if they can talk you through it.
I’d like to hear the Marquees–if they sound anywhere close to the big panels they would make for an awesome home theater experience.
I don’t know anything particular about the Marquee specifically, except it is a hybrid electrostatic-dynamic driver center channel speaker.
The speaker needs to be plugged in to power bias for the electrostatic panel.
The bias should be turned up as high as possible without causing any sparking type noise. It is easiest to adjust this without any music playing.
Brilliance is high frequency response adjustment.
Older models of SoundLabs are less efficient than newer models. Yes, it makes sense that the speaker plays quieter.
Hello, I picked this up at a local estate sale. I believe it’s an older model, light oak exterior. The brand is also new to me. The speaker doesn’t seem very loud. I have adjusted the brilliance and bias. The brilliance works but the bias does not. Whether the speaker is plugged in or not doesn’t seem to affect volume either. The cross over looks visually fine and well made. Any guidance appreciated.