To clarify "punch" what I really meant was tighter bass. Not really concerned about knocking pictures off the wall. Want better musical performance. What I was originally trying to figure out is with the large room would adding an extra sub or new sub allow for both musicality and the rumble.
Then I suggest that you play with your current subwoofer to see if you can get better performance by tweaking. Changing its location will have an huge impact on what room modes it excites and may help “tighten up the bass.” Also playing with the distance settings can also help. Don’t count on your receiver to set the correct subwoofer distance. Even if you measure it and set it correctly it wouldn’t hurt to play around with the distance settings. A friend, who use to engineer audio, and specialized in doing cannon sound effects took one listen to my auto settings during “Master and Commander” and said my subwoofer distance was off. He tweaked the distance some and the cannon shots went from “Booooooooom” to “Boom.” I would just focus on doing this for your primary seat and if it works then you could look at adding another subwoofer to smooth out the bass response across all your seating.
Something else to consider is bass traps. Might be no matter where you put your sub traps might help it’s overall performance.
Also I’ve found that for very large rooms having full range tower speakers for mains can help produce better bass than a subwoofer + bookshelf combo. Though this somewhat depends on speaker distance/position relative to room size. It’s also possible a completely different subwoofer would make a difference.
However, before doing anything else I would play around with your present subwoofer to see if you can get any improvement.
Cheers,
Dean
