@drlou77 While REL makes better subs bar none, they come at a much higher price point for the performance, and with your room size and current components, SVS would be the wiser investment in my opinion, especially in your budget. For less than $2K, most of REL’s offerings will not be true subwoofers, but more music woofers (most will not stop below the 30Hz or mid 20’s).
Due to the lack of configuration features, REL’s peak performance will also rely on meticulous placement and positioning to ensure phasing and integration are properly done. SVS on the other hand is fully configurable from a mobile app on your phone. Everything from gain, crossover point, phase, polarity, and parametric EQ can be controlled right from your listening chair.
For your room, I would suggest a pair of the SVS SB-3000 if you can make room for them, the full sized ones and not the Micro. The SB-2000 Pro would also do well in the room, take up less room, and cost less, but the SB-3000 will play more effortlessly and will be able to overcome the modes/nulls in your room better, which will make your whole system sound clearer.
The reference system I have built retails in the $250K-500K range (I lost count), and I still own a pair of SVS-SB4000. I started with a pair of 3000, but they were a bit too small for my larger room. I’ve tried a few REL subs, and only the big boys that retail $5K each and up were sufficient. At this point, while I still sometimes consider jumping to the REL No. 31s, I’m further leaning to a properly integrated Audiokinesis Swarm. But still, to this day, I’m very happy with the performance of the SB-4000, and I have a feeling I’ll be holding on to them for a while longer.