Subwoofer for large room

Dear Fellow Travelers,

One of my systems is used in a largish living room (80 sq.m, 3.5 m high, 280 cubic meters; 860 sq.-11.5-9900 cubic, in foot/feet).

I’m looking for a subwoofer (most likely: two) to add to my speakers. I mostly listen to classical music and acoustic jazz and would love to have more of the 32 feet principal pipes, the cannon shots, the atmosphere and suchlike :-).

Please don’t recommend subwoofers priced above USD 5000 each.

Thank you.
Rythmik subwoofers. They'll have any size and budget you want. Very reasonable prices and perform perfectly. I have 2 sealed 15 inch rythmik subs and they do a great job in 5000 cf space. I suggest bigger or dual subs x 2 for your space. Their website has a chart of how each of their subs perform sonically in terms of low bass output.
My suggestion is for dual Power Sound Audio S1500s.  I’m running one in a 10,000 cubic foot room... great tone, lots of slam. 
Thank you all. I'm now auditioning a pair of borrowed Velodyne spll1200 Ultras that came from a friend, at least to hear the difference between single and dual subwoofers. 
I’m biased towards SVS, I own their SB2000 and PB4000. The PB is monstrous and has never disappointed me (wife hates it, as it rattled and broke stuff in the pantry). You can check out their 16 ultra subs. 

Most importantly, SVS gave me amazing after sales support, they overnighted an amplifier module when my SB2000’s module unexpectedly gave out after a year. Their customer service has been amazing to me. Just my two cents if that matters to you.