rbodner wrote: "I have electrostatic highbred speakers (Martin-Logan Summitt X) - any thoughts on distance from The wall behind the speakers or the side walls? And toe in?"
The distance to the wall behind the speakers is ime what makes the biggest difference with dipoles. Basically, the more the merrier. If the bounce off the wall arrives too early, it can degrade clarity. Ime five feet out from the wall works well - you get a nice deep soundstage and great clarity, along with rich timbre. If you have to place them any closer than three feet from the wall, then you might try aggressively absorbing the backwave because it may be doing more harm than good. Back when I was a SoundLab dealer I had them out about seven feet, and I also liked to put a bushy plant (ficus tree) in the first reflection zone behind each speaker, to diffuse the backwave.
Dipoles can go very close to the sidewalls because they have a null to the side. Mere inches is okay.
Use whatever amount of toe-in gives you the best imaging over however wide a sweet spot you want to optimize for. The Martin Logans have a narrow enough pattern that even a little bit of toe-in avoids a strong same-side-wall reflections.
EDIT - oops, I didn’t see Kalali’s post; I shoulda refreshed the page. I agree with everything he says.
Duke