I'm a non-owner but I have interest in this particular brand of speakers. Needless to say, I stand corrected by the manuf & any other Merlin owner.
For 1 thing, the MM cabinet is less damped (lower Q) than the MX cabinet (which is higher Q). Thus, the VSM-MM is more forgiving & tends to match w/ a wider range of power amps (vs. the VSM-MX).
For 1 thing, the MM cabinet is less damped (lower Q) than the MX cabinet (which is higher Q). Thus, the VSM-MM is more forgiving & tends to match w/ a wider range of power amps (vs. the VSM-MX).