So you run your subs at 80hz and midbass at 60hz?I always overlap my subs and my midbasses, and something I've found helpful is to mess with the delays of ONE driver.
For instance, when my two subs and my two midbasses are running with no delay, I have a whopper of a peak at 60Hz, something like ten dB. Obviously, this is a room mode, the four drivers are hitting a room mode.
The "normal" way of fixing this would be to use EQ, which I tried. And it wasn't satisfactory; when you're using a "cut" of ten decibels, it's just going to sound weird, that's a lot of EQ.
So here's what I did instead:
1) 60Hz is 567 centimeters long.
2) Sound travels 34 centimeters in one millisecond
3) 567 divided by 34 is 16.67
So I delayed ONE subwoofer by 4.34 milliseconds.
What this does, is it puts one of the four drivers ninety degrees out of phase with the other three. If it was a "full" 180 degrees out of phase, you would get a perfect null. By delaying it by just 90 degrees, the one of four drivers is about fifty percent out-of-phase, but not 100% out of phase.
The net effect?
The peak at 60Hz disappeared. In other words, a delay of just 90 degrees on one of four drivers was enough constructive interference to completely nullify a peak in the overall response.
I imagine you could do something similar to fill in a null. IE, if you have four drivers playing at 60Hz and you have a dip, you could make one of them 90 degrees out of phase to 'fill in' the dip.
I wouldn't do this 'delay' trick with midbasses, because they cover a wider spectrum. My subs are lowpassed at around 80hz, so the delay that I introduced doesn't have much of an impact at high frequencies. But if I had delayed my midbassed by 4.34 milliseconds, instead of my subs, then there's a possibility that the delay would introduce peaks and dips ABOVE 80hz. For instance, a delay of 90 degrees at 60Hz is a delay of 180 degrees at 120Hz, and that would introduce a null.
I know this post is kinda confusing, and as always, I recommend trial and error and a lot of measurements. My main point is that overlapping your midbasses and your subwoofer can give you some tools that are not available otherwise. For instance, if you only have two drivers playing at 60Hz (your subwoofers) then this trick I describe is not as effective.
One way to visualize the tricks that I am describing, is to learn how cardioid subwoofer arrays work:
During my interview with Dave he explained a subwoofer array that he developed during a Blink182 tour. Here’s what it looks like. Here’s where Dave explains it in the interview, starting at 45 minutes. This came out of the sub testing that I did, primarily on the Blink 182 tour and then finished...www.sounddesignlive.com