i can think of 2 reasons that your bass comes from one side;
1: your x-over is set at too high a freq.
2: some of the bass freq. you refer to contain some higher frequencies (higher harmonics?) that are directional because they are higher than around 80 Hz or so.

try it again with pure tones around 30-60 Hz.
those should be omni directional.

about having 1 or 2 subs: 2 subs are ok if they are not very dissimilar.
you should not have any trouble using a 500 and a 800.
check my gallery for that.

Last edited by J. B.; 07/07/14 03:08 PM.
See: http://www.blu-ray.com/community/gallery.php?member=Gelli
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