Two subwoofers or One?

Put your Descent (just one) exactly between your speakers and set the phase angle switch to 90 degrees, crossover point to 35 (I know it sounds low but just try it.)

Set the volume to 12 o'clock to start.

Then adjust the 25 Hz boost and cut by starting low and very slowly raise it until your perceive a marked "thump" to the bass (depends on your material of course, but anything with a continuous good beat, but doesn't have to be unusually loud) Then, back off two tick marks.

You can then adjust the volume to taste -- but here's a little tip about using a Decent or Depth easily (if you're not too anal, aesthetically -- actually it looks kinda cool I think):

Because the woofers are in an omnidirectional layout 120 degrees apart, it really doesn't matter which woofer faces "front," the other two will wind up where they're supposed to. So if you point one of the two "back" woofers to the front, you will bring the rear control panel to the left or right front. I really like this because depending on the material, I do make regular subwoofer adjustments while listening. And it's much more covenient, both to make the adjustments and to hear the results, if you can do it from in front of the speaker system rather than standing (or crouching!) behind it. FWIW

Also, on an entirely different subject, with a room like yours, you might want to try setting up your speaker system in the center of one of the long sides of the room. You might be very surprised at the increased air and better defined audio image.

The usual advantage of using two subwoofers is that you will most likely spread out nodes due to room interaction.

Unsound, I know what you're saying, but for some reason (which I haven't really analysed) the omnidirectional radiation pattern of the ML subs seems to not excite room nodes to the degree that regular front firing subs do (I don't know about down firing ones.)

Nsgarch, I'm not familiar with this particular sub, so I must bow to your experience. It might be worth mentioning that it has been suggested that due to the summing of channels of stereo (i.e. not a dedicated sub woofer channel) signals to mono that it is actually possible to deplete information.

Unsound, What you are referring to did happen when people summed the L and R electrically by using a Y connector at the preamp and then running one IC with a mono amp for the sub. But if you keep the two channels separated electrically and either use a woofer with two voice coils (and a two channel amp) OR mix the channels with a buffered circuit and then use a single amp and voice coil, then that won't happen.

Whether one gains more spatial effects when two separate subs interact in the room has been debated. I suppose if a low frequency signal like cannon fire was clearly located on say the left channel, you would notice it, but anything below 120 Hz isn't very directional and I think the room would tend to soften that effect. It's the mid-bass and midrange that gives directional cues, and those are being handled by the main speakers.

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