The
CM9’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +0.83/–5.12 decibels from 200 hertz to 10 kilohertz. The –3-dB point is at 60 Hz, and the –6-dB point is at 49 Hz. Impedance reaches a minimum of 3.41 ohms at 116 Hz and a phase angle of –68.80 degrees at 66 Hz.
Sensitivity: 92.5 dB from 500 Hz to 2 kHz.
B&W CM9 Speaker System HT Labs Measures | Sound & Vision
If your listening distance is 10' away and your Peak SPL is 100dB per speaker (~103dB with both speakers playing), then it would require about 60 watts into 8 ohms or 120 watts into 4 ohms.
The subwoofer would help, so set your speakers to small and XO to 80Hz.
I think the best thing to do is get something like a Denon X4000 or similar. I think the power is enough. But depending on your individual case, if the power is not enough, you can always add an external amp later.
I used a Denon AVR-3312 for speakers like Philharmonic 3 (4 ohms, 85dB/2.83v/m sensitivity). Yet, it never had any issues. Well, except for getting hot.
Heat is always an issue. So make sure you have good ventilation no matter what you get.
You could probably get the X4000 for around $900 if you call Electronics Expo on the phone and talk to one of the sales reps.
