[QuadDiffusor]

Dear All,
Greetings from Hong Kong and Singapore where I maintain two homes, as I travel back/forth frequently.
Audio has been my passion since the 1970s, when I moved from Japan, the epicenter of consumer electronics in Asia (and globally, at the time).  Currently, I'm building a new home in Singapore, where I will have a dedicated listening room in the basement - a rather large one, with dimensions of 15'(H) x 23'(W) x 32'(L).  I've joined AudioCircle to hopefully connect with others who are experienced and familiar with acoustic treatment for large listening rooms, as well as high-end equipment suitable for such a space.  Looking forward to interacting!

[FullRangeMan]

Welcome to AC 
Please note the Fullrange Driver Circle:
https://www.audiocircle.com/index.php?board=128.0
This is the Open Baffle Circle:
https://www.audiocircle.com/index.php?board=90.0
This is the Tube Amps Circle>
https://www.audiocircle.com/index.php?board=144.0

Eminence Alpha 15A + 4.7mH + Visaton B200:

Lii Audio F15:

If one have a woodworker is possible try the Lii Audio F15($399/Pair) 97dB/8Ω and benign impedance curve sited to OB or Bass Reflex box or the F18($540/pair) no Crossover, no Tweeter beaming, no Phase rotation, no driver sensitivity loss, no Harmonics loss, no Retail price.
http://www.glowinthedarkaudio.com/lii-audio-f18.html

[Phil A]

Welcome!

[JLM]

Welcome!

How'd you come up with those room dimensions?  They're close to the Greek Golden rectangle (length would have to stretch to 36ft to comply.  My basement room is smaller (8ft x 13ft x 21ft - limited by ceiling height). 

I'd look for high efficiency loudspeakers and use a "swarm" of subwoofers, refer to Audiokinesis (Duke LeJeune, James Romeyn) or mastering speakers from the likes of PMC, Genelec, or Dynaudio.