I need a subwoofer/sub-bass opinion from you


Hello All--

I have a large room (well large to me).  It's 20' long, 15 wide, and 10' tall.  I run either Klipsch Forte IIIs or PSB Imagine T2s through a tube amp.  I have plenty of volume with either loudspeaker.  

What I want to accomplish is to add sub bass.  I did this previously in a smaller room with a Sumiko S5 (I believe it's the same or similar to the REL T5).    When I had the Sumiko dialed in, the system congealed into a wonderful sound.  There was no noticeably appreciable sound coming from the sub.  Instead, it merely filled out the lowest octave and added space, dynamics, and really made the highs seem less harsh.  

The Sumiko S5 does help in this setup but it's just not enough to charge the room or at least add enough.  

I'm thinking REL.  Thoughts? 

PS  When I ran the Sumiko, it sounded clearly better when I ran it off the amp speaker outs than off my Primaluna's dedicated subwoofer out. 
128x128jbhiller
Is your system for Home Theater or music ? If both what % of each.
Are you looking for new or used ? Is there a budget in mind ?
We can give much better recommendations ...if we know those answers.

@grey9hound great points. 

100% 2 channel hifi music. I’d consider used for sure. Budget is flexible. If I was convinced spending above $2500 would be wise I’d do it. Ideally I’d like to not spend more than that or $2k. 
If you are handy with tools I would add an infinite baffle subwoofer.Inexpesive and will work better than any subwoofer that you can buy.
My room is 24 x 25 x8 and with two SVS SB2000 subs there is plenty of very clear and low bass now. They have a home trial offer too which makes them a must evaluation. For me they are keepers.