REL T/9i or S5


Looking to add a subwoofer to my system in an 11 by 18 ft room.
For those familiar with the REL line is it worth it to spend the money on a new T9i or move up to the S series and buy a used S5 with the intention of adding another one later?
Right now the new S series is beyond my means.
Thanks
roxy1927
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.
Thanks for all your responses. I'll be getting something in the lower end of the S series.