How silent are the subs in this configuration? I realize that completely open air, you get equal wave cancellation but this is a little different. You have some of the subs under a mostly enclosed couch and that couch can easily act as the speaker box. And while it may not be a great speaker box, it's probably enough to at least let the BOSS create some sound.
Even when I mounted my earthquake MQB-1's in my couch I was able to hear some resonation from them. I had to move them externally and the sound was gone.
Video: JVC RS4500 135" screen in pure black room no light, htpc nvidia 1080ti.
Audio: Anthem mrx720 running 7.1.4, McIntosh MC-303, MC-152, B&W 802d3 LR, B&W HTM1D3 center, B&W 805d3 surround, B&W 702S2 rear, B&W 706s2 x 4 shelf mounted for atmos, 2 sub arrays both infinite baffle: 4x15 fi audio running on behringer ep4000 + 4x12 fi audio running on 2nd ep4000.