Bass management with stand alone preamps

What are ESL? Martin Logan speakers?

Electrostatic loudspeakers. Martin Logans are ESLs from about 250 Hz up most of their speakers cross over to standard woofers. I think they still make one full range ESL. ESLs run on a different principle than regular dynamic divers. In the middle of the speaker is a charged mylar diaphragm. Charges up to 4-5  thousand volts are not unusual. On either side of the diaphragm is a "stator." This is a wire or metallic grid that is driven push pull by the amplifier through a step up transformer converting current to voltage. Like charges repel opposite charges attract. Thus the diaphragm is moved back and forth to the music. An entire 8 foot by 2 foot diaphragm weighs less than the voice coil of a 10 inch woofer. Every molecule on the diaphragm is driven and controlled 
by the amplifier. There is no cone flopping around.  The only disadvantage is that by design they are much larger than regular dynamic speakers. I believe their size is an advantage especially when they stretch from floor to ceiling producing a perfect linear array at all frequencies. They are typically dipoles ( they produce sound 180 degrees out of phase from both sides front and back.) Which makes low bass difficult but a linear array dipole is the best way to deal with room acoustics because of their radiation characteristics. There is no dynamic loudspeaker that can better the performance of a linear array ESL especially when they are mated to an appropriately designed sub woofer system. It is not IMHO either. Anyone who hears such a system is dumb founded. Anything from a single Block Flute to the Pixies is produced with a dynamic realism that I have not heard produced any other way.
Google soundlabs speakers. These are the best ESLs you can buy at this time. 

No, I meant with the sub woofer.

Yes- Sound Lab used to make the B1 subwoofer, which was a large electrostatic panel. 

These are the best ESLs you can buy at this time.

Agreed. IMO they are also one of the top five speakers made anywhere.

I scrape by with 2 subs, and think the array thing is cool but impractical for my current setup...I also am a Schiit Loki advocate, used rarely but it's there when I need it. Note that an array shouldn't exceed 14 subs as that is, well, excessive. 13 is the max, look it up. Or no...don't look it up.

Interesting thread so far.  I’ll be playing with the bass management settings more in my processor based on some of the comments here. 

One other question - with the room correction equipment I’m holding it’s best to feed a pure digital signal but in the case of sacd none appear to accept hdmi DSD stream to avoid an extra d/a conversion.   Why are inexpensive receivers and Blu-ray players able to support DSD over HDMI but ultra pricey DACs or preamps rarely offer it?