Help wanted: Bass!

I’m in need of augmenting the bass in my system. I’m the old school type and would rather NOT go the sub route.

My system and environment:
• Pre:   Conrad Johnson Premier 16LS
• Pwr:   Conrad Johnson Premier 12 Mono Blocks
• Pwr Condtnr: Shunyata Hydra
• Speakers: Tannoy Kensingtons
• Cabeling: Stealth PGS IC’s, Vandenhull Bi-wire Speaker wiring
• Sources: Conrad Johnson DV-2B CD Player, SOTA Star w/SME arm w/Grado cart, Magnum Dynalab Tube Tun 
• Music:   Classic Rock, Easy listening, Female Jazz singers, Classical
• Room:   Big (25 X 30) w/cathedral ceiling. Harwood floors/ceiling and big glass windows. Rugs and furniture

Came across the Emerald Physics Bass Manager claims to add 1/2 octave of bass to any speaker. IYO, could that be a solution? Are there similar helpers like this out there? Not much in the budget (about $500) for a near-term purchase. Could double that for a longer-term.

Again, not wanting to go the sub route unless I have too. Can’t do room treatments or alter room configuration (it’s our living room) either.

Any thoughts/suggestions will be greatly appreciated – thank you!

I'll vote with Eric....get some measurements so you can analyze what's really going on before playing the 'musical equipment swap' game or other high $ experiments.  Treating the room (which you'd rather not do anyway) can be avoided with active eq, but that's MHO and upsets the purists.

Personally, I ignore the room and 'run' flat response, but that's my thing and not to everyone's taste.  But, to each...
Fireplace!!!!!   That's it.  Your lows are going up your fireplace.Block your fireplace, close the flue, etc.   I had an attic fan in my lows until I got a powered louver for the big hole in the ceiling.
All great suggestions from everyone and each in it's own way will add its own incremental improvements to your in-room bass response. I was in the same spot as you (and also own and use Tannoy D700's) but I didn't get the bass I was really looking for until I added a subwoofer. Good luck!