A friend has a room with some nasty bass issues. We've put a few subs towards the rear of the room to compliment the existing sub that's not too far from the speakers. It has helped quite a bit.
Yet the bass is still pretty uneven from seat to seat. I understand that the best solution would be to add flanking subs in the front to add more subs (and to reduce boundary issues) but that's probably not going to happen right away.
So, with 3 subs available to us is there a better way to pick optimum locations other than just trial and error? We don't have measurement gear to help us. Does using a room mode calculator give any clues as to where a sub might do it's best work? Should we put a sub in or outside of a mode?
Wayne Parham Messages: 18791 Registered: January 2001
Illuminati (33rd Degree)
You could certainly try Geddes original proposed multisub arrangement, which was "one in a corner, one along a side wall and the last one 2/3 the way up to the ceiling along another side wall."
For reference, the link below has information about the commonly proposed arrangements, Welti, Geddes and mine:
Wayne Parham Messages: 18791 Registered: January 2001
Illuminati (33rd Degree)
He was trying to address vertical modes by staggering the height of that one sub. Problem is, vertical modes are higher in frequency unless the ceiling is unusually high. And since you cannot high-pass distant subwoofers high enough to smooth those frequencies without making them sound unnatural, you might try a modified arrangement, leaving the third sub on the floor. It's probably more convenient anyway.
You could place the third subwoofer somewhere "random" but other than a corner or wall midpoint. While that's not Geddes specific placement instruction, I do believe it captures the spirit of what he was trying to do, which was one corner, one midpoint and one "random" placement.