What process did you use to integrate multiple subwoofers for 2 channel listening?

@hilde45 -  The problem I’m not able to solve, and perhaps the room’s physics make it impossible, is a +5db or more bass hump from about 73-92 hz. This is evident in REW and it’s also easily noticed with music. A tubby zone. The idea that one more sub would solve this is implausible.

I have the Swarm DBA from AudioKinesis in my system.  There was an issue with shipping causing the Dayton amp and two subwoofers to arrive a few weeks before the rest of the system.

Not wanting to wait for the other two subs, I hooked up the Dayton and one sub at first.

Yes there was an increase in bass quantity but not quality.  The next day, I connected the second sub and noticed an improvement.  Bass was less bloated and seemed better timed.

When the other two subs arrived, I connected a third and again noticed improvements.  Perhaps the same type of improvement to a lesser degree.

After connecting the fourth sub, I couldn't hear anything negative with the bass response.  No bloated or slow bass.  Even the higher frequencies showed improvement.

I have used the DBA in a small 11 x 13 (minus closets) room and also a 12 x 15 living room at my old place with outstanding results.

The DBA continues to shine in the 15 x 19 listening room I have at my new place.

Hope this is helpful to you!

@hilde45 -

Duke LeJeune (AudioKinesis) wrote:
So imo you are definitely playing the distrubuted multisub game already! If you can elevate one of the subs so that it is closer to the ceiling than to the floor, you get bonus points. This is one of the things that @hleeid did to get good results in his 11 x 13 foot room; I think he actually elevated three of the four Swarm subs, as that was more practical than the other way around in his room.

So yes.  That is true.  The room was actually a bit smaller due to closets. 
Had a conversation with Duke about this. 

Even Duke had reservations about the extremely small room.  But I mentioned to him a thread he posted about elevating one or more subs above the room mid height which would contribute to dispersion in the vertical plane.

The light bulb went off in my head.  After some measurements, I figured a way to make 4 subwoofer easily fit by elevating three of them.
One was mounted on the wall behind me above my head.
The one sub on the floor also served as a lamp table next to my desk.

NOTE:  The only limited floor space sacrificed was for the ''lamp table'' sub.

NOTE 2: I must respectfully disagree with Duke about my good results.
They were not really good.

Shockingly incredible would better describe the experience!  Even before hooking up the 4th sub, let alone elevating some of them.

In my new place, I have my mains (Harbeth SHL5+ 40s) firing diagonally across my 13' x 16' (9' ceiling) office.
Two subs are ceiling facing.  One at 12'' and the other 18'' from the ceiling.
Each of these are near the corners along the long wall.
One sub on the floor is slightly behind and to the right of the right speaker.
The other floor sub is to forward and to the right of my desk (my listening position).

After much experimentation with speaker/listener position, light acoustic treatment, etc. I feel this is my best (currently) sounding setup all around.
No DSP, EQ, etc.  except for reversing phase on the sub closest to the mains and unporting the sub furthest from the listening position.

Best of luck to you on your quest!

No worries!
Great to hear of your progress!
You are in for a delight!
Enjoy!