johnnycamp5 Messages: 354 Registered: June 2015 Location: NJ
Grand Master
The floor can make a big difference.
I had something like you describe once above a 2' crawl space with a floppy (spongy) floor.
Until I could make the floor more solid, a bag of play sand on each speaker helped lol.
I hope you had those flanking subs turned way down low, barely audible between on and off.
It's hard for them to make things worse, unless the gain is way too high, everyone's situation is different though.
Did you use 3pi's?
I had trouble blending expensive scan speak subs (with passive radiators) to my mains. I couldn't cross them over higher than about 50-60Hz without things getting very muddy sounding.
When I switched to the Lab 12's It became very hard to make them NOT blend with the mains.