Haha, the truth, or more of it finally come out, now you are talking..:D:D\nMost of the T-system and SVT Towers are meant to be bi-amped = using 2 power amps per tower = one amp for top cabinet (92dB\/2.83V\/m),one amp for bottom cabinet (90dB\/2.83v\/m).\n\nThis means 5 towers = 10CH amps and 4 ceiling speakers = another 4Ch amps for a total of 14Ch amps.\n\nSo I use the MX-A5000 to power the 5 top cabinets and 4 ceiling speakers.\n\nLike you said, the key word is the VOLUME.\n\nBack when I had the 60WPC ATI amp (AT6012, which is 60W x 12Ch),I actually used this 60WPC ATI amp to power the bottom cabinets of the T-system. And it worked great. I got tremendous amount of clean bass.\n\nSo if I got great bass from the SX-1010 bottom bass cabinets using 60WPC amp, I am confident I could get great bass from 150WPC amp.\n\nBut it's all relative to the VOLUME and frequency, as you repeated said.\n\nThese 90dB\/2.83V\/m subwoofer cabinets are also for 20Hz+ in-room response, not 10Hz. So if I were going for 10Hz at 110dB, that would be a totally different story.\n\nBut 20Hz and above frequency at probably no more than 100dB volume, it seems even a 60WPC amp is fine.\n\nMy first ever subwoofer was a 10" NHT subwoofer with an 80W amp. And even this single subwoofer shook the 18'x20' room really well.