A lot of times the corner of the room is where the sub works best. Where is your current sub located in your room? Adding a 2nd sub gets complicated to setup and doesn’t add much other than more coverage for multiple listening seats. Does your theater have multiple rows of seating? You only gain a few dB with a second identical sub and won’t get any better performance than the original sub. A good ported 12 from HSU or Rythmik or SVS should work in your room. 1500 cubic feet is not a big room at all. My Rythmik 12 in LVX12 shakes the room in my 2600 cubic feet theater, but it is also super smooth for music.
. I’m glad I didn’t do a 15.
