Yes, this is somewhat true. One of the ways I made some strides in this area was to change from Transparent to MIT speaker cables. The MIT did wonders for clearing up the mud I was hearing in the mid bass. Ironically I just sold my Transparent cables.
Another thing I've noticed is dynamics - reduced - on the Magicos. It's got me thinking about what is more natural. For example, one of my favorite tunes (both from audiophile and music perspectives) is The Girl From Ipanema by Getz/Gilberto. The bass in that song is pretty darn robust and would almost overwhelm on my Alexias but is rather subtle on my S5's. But that's beside the point. When the sax comes in, I'm used to it being huge and a couple phrases into it, some notes JUMP out at you and almost bowl you over they are so dynamic (i.e. they are so much louder). On the Magicos this is not very pronounced - the volume doesn't change much. You sense some amount of emphasis on Stan Getz' part, but nowhere close to what the Wilsons deliver - it's like the performance itself is different. Now, sometimes dynamics are unsettling - I would sort of 'brace myself' for those notes where as now it just sort of floats by...
I'm not sure what to make of this just yet.
Gat yourself an RTA app and look at the region these notes are jumping at you. You will soon notice that they do jump, on everything you listen to (perhaps not in the same intensity as they do with a sax). It is not dynamic range, it is uneven power response. Once you “hear” that coloration, it is all over