I have M60i speakers which I power with NAD 751 (60 wpc) AV amplifier.

I like the sound overall, but midrange (male vocals) seems to be a little weak comparing to base and highs.

I was considering tube amplifier to cure that.
I looked at Assemblage (Sonic Frontiers) 300B SET amplifier which gives me 8 wpc. Considering 95 dB & 8 Ohm of the M60i would 8 Watt be sufficient to drive my speakers?
My listening room is (7m x 3m).

What about biamping them with tubes for mids & highs and using SS NAD for lows ?