David,How many sub-woofers do you have? How are they located?What is a powering bed channel?
Barry,All my subs are treated as "1" sub because of the Mini-DSP. I currently am using a total of 5--the SVS cylinder in the front left of the room, a HSU sub on the right side about 1/3 ways from the front to the back of the room, dual JL Audio subs (daisy chained off the same signal) on the front wall 1/3 towards center, and a SVS SB3000 on the front wall also 1/3 towards center (basically these are on opposite sides of the center channel). The subs were gain matched to work as "one" subwoofer with EQ applied in the MiniDSP (under normal use...right now I'm reviewing a Trinnov Altitude 16 pre/pro and disabled the MiniDSP EQ and let the Trinnov handle the EQ duties). What's amazing about the Trinnov is it was able to EQ the sub channel perfectly in less than 20 minutes of calibration....when I did it manually with the MiniDSP, it took me close to 10 hours to get it "just right." It would take me less time now that I've done it before...the first time I did it was painful, to say the least. The Trinnov room correction is by far the best I've ever used and puts every other system to shame.
It would be a lot easier and faster if you had four identical subs I bet.