It depends on how much low end you are looking for. I have a 4500 CF room and a PB13Ultra and its not enough.
The PB12 is no slouch either and will do a decent job but you may find that when you push your system it will give up if your listening to uncompressed audio form some movies.
Welcome to the forum! I'm going to answer with a qualified yes.
Your space is almost exactly the same volume as my home theater. I'm a satisfied owner of the PB12-NSD. I can enthusiastically recommend it. The qualification in my answer comes from our listening habits. We don't listen to music or watch movies at insanely high output levels. I also prefer a more integrated sound, not bottom heavy like I've heard in some systems. We also don't watch a lot of action films filled with explosions. We did watch "Dark Knight" with some friends at a higher than normal level and the sub had the doors and pictures rattling! I'm actually going to go back and add some foam strips to the door jambs of the two closet doors to help control it. Also, there are two scenes ("The Abyss", "Darla") in "Finding Nemo" that are downright frightening even at moderate volume!
I've cranked my system to uncomfortable levels (at least for me) and the PB12-NSD didn't give out of gas. I've measured the in room response and I'm down 3db @17hz! It's pretty flat in my room from 20hz up to crossover.
As others have said, it depends on your listening levels. A single PB12-NSD should be fine if you only plan to listen at moderately loud listening levels. However if you ever like to really crank the volume a single PB12-NSD will probably be insufficient for a 3500 cubic foot room.
To give an idea of the role personal listening habits play in subwoofer selection, my room is <1000 cubic feet. I had a single PB10-NSD in there but found I wanted more. I added a second PB10-NSD which held me over for a while, but eventually I sold them both and upgraded to an Epik Castle (said by some to be similar in performance to the PB13-Ultra) which completely satisfies me. On the other hand, most people would find even a single PB10-NSD to be more than enough subwoofer for my room and likely even larger rooms. Ultimately it really depends on your own listening habits and preferences. The PB12-NSD is a very good sub and I think as long as you don't plan to listen at very high levels it should put a big smile on your face :yes:. Good luck with your decision.
Sounds good ThomasC. As long as you aren't looking to really crank the volume I think the PB12-NSD should offer an excellent HT experience in your room. Let us know your impressions once you get the beast :yes: