I just found this on the Anthem website...
Q20: I have two subwoofers and want to use them in stereo. Can the surround preamp's subwoofer outputs run in stereo?
A: No, although the same job can be done by disabling the sub channel in the setup menu, then hooking up the subs through their own crossovers to the front left and front right channels. This is not recommended because a stereo subwoofer configuration has little value. Few recordings contain real stereo bass info, (e.g. large pipe organ using widely spaced microphones) and unless the subs are located outdoors and away from the ground, they can't reproduce it anyway. Inside a room, running them in mono instead is beneficial because they can be moved to wherever they create the least amount of resonance individually, and as a combination, make each other's response peaks and valleys less severe. As well, a "bass spaciousness" effect can be dialled in with the phase control if it's available on one of the subs (which is what happens when two widely spaced microphones pick up a low frequency source - same long wavelength, different phase between the two).
FYI...
Q20: I have two subwoofers and want to use them in stereo. Can the surround preamp's subwoofer outputs run in stereo?
A: No, although the same job can be done by disabling the sub channel in the setup menu, then hooking up the subs through their own crossovers to the front left and front right channels. This is not recommended because a stereo subwoofer configuration has little value. Few recordings contain real stereo bass info, (e.g. large pipe organ using widely spaced microphones) and unless the subs are located outdoors and away from the ground, they can't reproduce it anyway. Inside a room, running them in mono instead is beneficial because they can be moved to wherever they create the least amount of resonance individually, and as a combination, make each other's response peaks and valleys less severe. As well, a "bass spaciousness" effect can be dialled in with the phase control if it's available on one of the subs (which is what happens when two widely spaced microphones pick up a low frequency source - same long wavelength, different phase between the two).
FYI...