HTS Moderator , Reviewer
3900 ft^3 is too large for a single PB-1000 I'm afraid. You might be OK with one PB-2000, but anything smaller will just get swallowed up by the room. Your situation almost requires a ported subwoofer - as they are known for higher output levels - so the ULS is probably not a good choice in this case. Not a single, anyway.