The M16 has a listed sensitivity of 86 dB. 50 watts represents 17 dBw, so 86+17=103 dB, measured at 1 meter .
What is your listening distance? At 3 meters, your SPL is a nominal 93 dB, which is quite loud.
We don't typically listen in anechoic chambers though. As a rule of thumb, SPL per pair at 2.5-3 m ≈ SPL at 1 m anechoic. Specifics would depend on the room in question.
That would mean about 103 dB peak at listening position, about as much as recommended but not excessive by any means.
BTW, according to the M16 review, average sensitivity is more like 85 dB. A bit on the lowish side.
If your amp "needs some help at higher volume", you might benefit from a subwoofer to take the load of low frequencies off the M16.
Good point. They're 10 dB down at 40 Hz (anechoic) anyway.
What about a D class power amp, lots to choose, cheaper than Rotels and measuring fine.
You have to be careful though, a bunch of them are IEC Class I. Watch out for ground loops.
In case of sticking with Rotel, the power amp seems like the better deal. It would require close to 2 Vrms if input for full power though, which the A11 (spec: 1 Vrms out) may or may not be able to provide. For much less than the $1200CAD difference one should easily be able to find a headphone/preamp to take up the slack though, a lot of the $100(US) usual suspects would do the business (Atom Amp 2, Magni, L30 II etc.).
BTW, right now 1 USD = 1.42 CAD.
