Something about that Crown calculation seems off or over my head… If the M4 is 90 db efficient for 1w/1m, 2 watts should provide 93 db, 4 watts 96 db, 8 watts 99db, 16 watts 102 db, 32 watts 105 db, and so on…
Even at 10’, the falloff in SPL can’t be that much?
Maybe the 3db amplifier headroom is what I don’t understand? And make no mistake, I’m no tech genius trying to bait anyone into a debate- I’ve just always read that to increase a speaker’s output by 3 db requires a doubling of power for each 3 db increase in SPL.
As far as the cable gauge goes, I agree with Ron that for a 6’ run, you don’t need it all that heavy. Because of my domestic stereo in the living room scenario, I have 23 and 25 ft runs feeding my M3 Turbo S, so I use Supra 9 gauge. I’d love to experiment with some other wires, but at those lengths it is prohibitively expensive.