Thanks for taking the time to write such a detailed review. Not many M40 reviews to read so it’s more helpful than most.

Interesting that the soundstage starts behind the speakers and extends back. I have the opposite experience with the M80s which IMO and that of Sean (StPatGuy) project a bubble of sound out in front of the speakers. Also interesting you comment on the tight bass. Seems to be a common theme with Axiom speakers as I’ve seen similar comments about all their tower speakers and was a significant reason the M80s beat out several competitors to win a place in my starting lineup.

I feel the M80s also have the same potential graininess/harshness in the highs on some tracks but when I compared those same tracks on my Sennheiser HD600 I found it was still there. OTOH I have found that on other tracks with lots of intense highs there is no problem so I’ve concluded it’s what’s on the track and not anything being added by the speakers at least in my case.
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3M80 2M22 6QS8 2M2 1EP500 Sony BDP-S590 Panny-7000 Onkyo-3007 Carada-134 Xbox Buttkicker AS-EQ1