Does the sub have speaker inputs?

If so (and the way they used to be hooked up all the time before receivers had good bass management) is that you run from the receiver to the subs speaker inputs, then from the sub's output on to your speakers.

That way a crossover in the sub would 'take in" the bass portion of the signal, and "pass on" the rest of the frequencies to your smaller speakers.

THAT would take the burden of bass off the M3s.

::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::