I had a sound specialist come over recently and take some response frequency measurements from around the room and found that, due to the dimension of the room, there were deep bass holes right at the listening position where the volume at certain frequencies fell almost to zero. We found the best location to minimize this, but there's still a range of frequencies (I apologies - I don't recall specifically from what Hz to what Hz) that don't make it to the seating position.
The sound specialist told me that I could either (a) move my seating back by 1 foot or (b) add an additional subwoofer. I won't bore you with the reasons, but (a) won't work, so I'm looking to get another subwoofer for the room. The PB-13 Ultra is in the back of the room, so I think the sound waves from the sub hit the front wall and cancel out other sound waves right as they meet at the listening position. The purpose of the 2nd sub would be to sit in the front of the room and offset the cancellation. I think I would need to put it in phase, but I'm not 100% sure. Could be out of phase.
Long winded intro to my real question, which is: what sub should I get? The PB-13U in the back of the room works great for the majority of my bass needs, so I don't think I'd need something as powerful. That said, I really don't want to distort the PB-13U by pairing it with a cheap sub that farts out bass. Not sure if timbre matching applies to subwoofers? I also used up all of my WAF points by getting the first PB-13U, so I'm not sure she'll be ok with getting a 2nd one.
Apologies if this is the wrong thread for this question.