REL T/9i or S5

One of the nicer subs I found in that range the Rythmik F12G.  I owned a S/3 for 4 years and tried T-9 lent by a friend for 2 weeks.  The Rythmik is worth looking at.

I have a pair of T9i's that I use with my Tannoy Stirlings in a room a little bigger than yours.  I can't speak to the S line, as I never got the opportunity to hear them.  I'm sure they're wonderful.  But I find the T9i a *highly* musical sub.  Very fast and tuneful, which is what I want in my bass.  I want tones from a double-bass, not boom or rumble.  They certainly could overpower a room and muddy up, but they're so adjustable it's easy to avoid that.

There’s no substitute for quality the S line is considerably  better. All the best

That plain looking 400 watt 8" one that’s wireless with auto standby and an iPhone remote control w/equalization app? It retailed for $599. but can be found two for $899?

Sorry I can’t remember the REL model number, SLF something and a funny name? I think the Absolute Sound reviewed the 12" version?
Wish I could be of more help, sorry.

Pair of used S3 will outperform T9s. I have the S3 SHO and it blows away the Strada lll I had before.