subwoofers and panels don't mix

Gregm...My three SW systems are "sealed enclosure" which as you probably know is not the same thing as "infinite baffle". The enclosures (which are all the world like coffins standing on end) are embedded in a wall. Their front baffles, which go floor to ceiling, are covered with acoustic foam (for the Maggie backwave). Fabric goes over the whole thing, so the SW systems are completely camouflaged.
Phasing is easily verified using my spectrum analyzer. (Out of phase produces a deep sharp notch at X/O).

OK, thanks. I thought the drive units were embedded in the wall.

I tried running Running two Velodyne DD 10's subs with built in room correction. These are awesome subs IMO very fast and dynamic. But intergrating them in my system, at that time was to big a trade off for bass. Using the high pass in the subs made the speaker and sub intergration very very good. But it made the mids and highs sound electronic.

And by not using the high pass, and just using the room correction, I could never get the seamless intergration with the main speakers which were ML Odysseys. I ended up selling the two subs and the speakers and bought a better full range speakers. The Martin Logan Summits with built in Subs. Which are every bit as good as the Velodyne Subs. Now their is no trade off.

However, if you pre amp is processor based and your using that with the 2 Velodynes DD 10's it would intergate the bass very very well.

But in an all analogue system I don't think can be done. With good results

I have heard Nola Thunderbolts sounding very good with Maggies. The TBs are very fast and transparent - musical is a term that gets tossed around without much meaning but it does apply in this case.

When I sold my last pair of Maggies ten years ago, alas, the TB was not available.

Hmmmmm, I have been thinking about adding a sub to my electrostats. I had not thought about the above problems. Now I probably won't try as i can do better without than a poorly mated 'with'.