I think what you want to do will work fine.
People have talked about the phase difference problem, and there is a problem in that bass arriving at your sub from different channels will have been delayed differently.
But I don't think it will be too much of a problem because phasing is less of a problem at lower frequencies, and because your distance differences will probably not be more than a few milliseonds.
Of course, someone else can come in and correct me on this if they'd tried this and noticed problems with the time delays.
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Matthew J. Hill
matt@idsi.net
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Matthew J. Hill
matt@idsi.net