I have a single REL T2 (8" driver+ 10" radiator). 10'x15' room. I can barely turn on the gain knob or the bass is overwhelming. The notes about the phase switch and placement seem best. You can also play with the crossover point to put it higher so the REL plays more of the audible bass frequency-even though that is not the REL method. The notes about needing two seem less relevant to your issue. Good luck!
Gain level on a REL sub
Hi. I have purchase a REL R 218 sub to compliment my system and as far as sounding musical, I am happy. However, the gain is almost all the way up and I don feel that punch and slam I am looking for. Musically I am impressed with it but I still dont feel that level of impression overall. When I had the HSU STF-2, it was in a different league with in terms of impact and punch but for detail, the REL was better. My question now, Do you think I should try getting a another REL with the same model for a stereo pair or go with a different sub? My room is pretty small but it is treated with acoustic panels.