Originally Posted by gtpsuper24
I think that means placing a single subwoofer in multiple locations like one on each wall front, back and sides, or all four corners or some other combination. Its mostly room dependent though, I get much better results with dual subwoofers spread out ie one between my front left speaker and center and another along the right side wall midway. That seems the best way to help bump those bass nulls up or at least flatten the freq response.
I think its proven quite a lot that multiple subwoofers in multiple locations is the best way to get the flattest freq response.
The Harman paper on multiple sub placement is inevitably posted as the 'proof', but it's only a planar study. Stacking was not investigated. There are plenty of holes in the Harman paper as well. Most of it is a virtual experiment in a virtual room and the space allotted for 16 seats is not even enough for 2 of the seats in my HT.
Most of the simulations were made in this 24’ x 20’ x 9’ virtual test room, with a 6’ x 6’ grid of seats spaced 2’ on center.
The FR graphs used in that paper are linear, not logarithmic and the vertical scale is 20dB per division, in which every FR looks fairly flat.
When you properly scale the Harman 'best' FR using multiples and normalize it to a standard REW log graph vs my final response (I use a combination of 2 floor locations and stacking and use no smoothing EQ, only placement, phase and crossover selection), judge for yourself which is better:
Otherwise, it hasn't been proven much at all. Maybe you could cite these quite often proofs?
Again, my point was not that multiple placement is an invalid choice, I'm just countering what was posted regarding stacking. A 33' high stack is not required for 20 Hz (that one should be obvious to even the most casual reader), floor-to-ceiling is not only not the least significant problem, it exists in every room with floor-only placement and in the example I posted of a real room with actual measurements, it was the ONLY significant problem.