Adding colouration between 80hz-100hz is precisely one of the reasons why many feel the midrange is recessed in the M3. To take this example further, equalize 10kHz-20kHz up so you now have a smiley curve. The midrange is still unchanged but you will hear how it kills the midrange even more. A somewhat neutral pair of headphones and a MP3 player with a equalizer will show you this also.
Now I think it is also due to the fact the M3 uses the 6.5" while the M22 employs the 5.25". It seems the 5.25" plays much nicer in the midrange noted by the different crossover points the 5.25" mates with the tweeter in the M2, M22, M60, M80 designs. You will notice the 6.5" is crossed no higher than 2.2kHz by itself.
