Daveyf1 wrote: " The more subs in the room, IME the easier it is to overload the room....and this really needs to be taken into consideration. "
If we’re talking about a setup where the user is careless with the level control for the sub(s), then I suppose that’s true.
However in a setup where the user takes care in setting the level of the sub(s), the improved in-room smoothness of a good multisub setup makes is less likely that a peak will "bloom" and overload the room.
That being said, there is a situation in which multiple subs might result in a rising bass response as we go down in frequency: Near the top of the bass region the outputs of the distributed subs will be combining in semi-random phase, while down at the bottom end of the bass region (where the subs are a relatively small fraction of a wavelength apart) their outputs are combining much closer to in-phase. Approximately in-phase sources combine more efficiently than do semi-random-phase sources. So if the individual subs are more or less "flat" across the bass region (not counting room effects), the net result can be too much output down at the bottom of the bass region. Fortunately the solution is fairly simple: Reverse the polarity of one of the subs, which not only corrects this in-room bass rise, but also improves the in-room smoothness. I suggest reversing the polarity of the sub which is farthest from the main speakers.
Duke
commercially affiliated with a multisub system
If we’re talking about a setup where the user is careless with the level control for the sub(s), then I suppose that’s true.
However in a setup where the user takes care in setting the level of the sub(s), the improved in-room smoothness of a good multisub setup makes is less likely that a peak will "bloom" and overload the room.
That being said, there is a situation in which multiple subs might result in a rising bass response as we go down in frequency: Near the top of the bass region the outputs of the distributed subs will be combining in semi-random phase, while down at the bottom end of the bass region (where the subs are a relatively small fraction of a wavelength apart) their outputs are combining much closer to in-phase. Approximately in-phase sources combine more efficiently than do semi-random-phase sources. So if the individual subs are more or less "flat" across the bass region (not counting room effects), the net result can be too much output down at the bottom of the bass region. Fortunately the solution is fairly simple: Reverse the polarity of one of the subs, which not only corrects this in-room bass rise, but also improves the in-room smoothness. I suggest reversing the polarity of the sub which is farthest from the main speakers.
Duke
commercially affiliated with a multisub system