Rel t9x or Rythmik F12G

I highly recommend Rythmik servo subwoofers, which can probably control the expected low-bass reverberation problems in your small room. They include superior adjustable EQ, which works better than phone-controlled stuff. Your small room does not need two subwoofers

@condosound Other than the fact that I also highly recommend Rhythmic subs there’s nothing else here I agree with. First, the “phone-controlled stuff” that SVS offers incorporates the considerable benefits of DSP (as almost all better subs offer now) and has the ability to control far more than Rhythmik currently offers. That you can do it from the listening chair rather than running back and forth from the sub to the chair is a considerable convenience feature. Rhythmic is just really behind the ball here when it comes to incorporating DSP into their subs. I recommended the SVS subs for their size, performance, DSP, price, and their generous trial period along with their excellent customer support. That said, at a similar price I wouldn’t hesitate to also recommend the OP consider a pair of the Rhythmic L series subs or even better the F series if they’re in budget. Both are larger than the SB1000s, which may be a consideration in a smaller room.

And the size of the room doesn’t determine how many subs are required or optimal, and as most experienced folks here have recommended, two subs are better than one for many important reasons and four are better than two if room logistics and budget allow.

I agree that for music only and in your small, square room I’d do two smaller subs versus one larger one. Your speakers go down to 38Hz (-3bB) and the T5x doesn’t go much lower than that, not that there still wouldn’t be benefits but with your speakers I’d be looking for a sub that brings more low-end info to the table — and there is very important info down there that greatly improves things like imaging and soundstage in addition to just more bass capabilities. I’d recommend trying a pair of SVS SB1000 Pro subs that are relatively small (about 13” square) yet still go down to 20Hz (-3dB) so it’s a true subwoofer with the benefits that brings. Plus they come with software that lets you more easily integrate the subs from your listening chair with your phone (which is really nice), and they offer a totally risk-free, 45-day trial including shipping both ways so if they don’t blow you away just send’em back. Last, a pair will only cost $1150 that seems to be within your budget. Read the reviews that are quite positive. Just another option to ponder, and best of luck.