Got popcorn. Rug is coming. I have to see what I can get away with as far as sound absorption........my other half wouldn't be too happy about my choice of decor in that regard.
cool! if you've got popcorn, completely disregard my comments about the ceiling.
have you, simply for shits and giggles, tried reversing phase on ONE speaker and see what it does in your listening position? Nulls and voids are a real thing with bass energy. a bass wave can be fifteen feet long, and if your seating position is in the trough of the wave, no bass.
Or, you could look into a pair of subs, that would certainly help smooth out the bass response in that big room.
I've run subs with all my speakers for thirty years now, and it's only with my 'end game' speakers that I've removed the subs from my main system, but my delta/gammas have dual 12" IMG woofers, and eventually will be servos, once I put the box in.
Everything else I've ever had, no matter how big, have needed subs to get the bass right. My main room is 12'X30'.
hell, in bedrooms I use smaller subs as well. You don't have to buy uber expensive subs, a pair of decent subs will do better then one more expensive sub, imo.
In a big room, it takes more bass to 'energize' the room, which Tom in is alluding to, (I think)