Maggies and rolled off treble

No, there is not.
The modern Magnepans are in fact the back side of the old Magnepan reversed to the front.

Jafox,

My intent is to give a counter-view as I suspect I would be classified as being in the neurotic camp where effort is made to refine a system in every way possible, including cables and tweaks.

And I respect where you are coming from. You are certain that an ordinary CD player will be woefully inadequate, as would an ordinary interconnect or cable. As the saying goes.....one bad apple and the whole lot will turn bad. It certainly has some logic to it.

However, I assure you that significant bass distortion is quite common in almost all popular aesthetic looking speakers with extreme LF response (small but sound big). Distortion is typically several orders of magnitude greater than what one would typically observe from a CD player or amplifier. Therefore you might consider this along with the CD player and wires in terms of what might need to be refined.

Dazzdax...Maggies have relatively low impedance. The wire on the Maggie diaphram is probably no longer than the wire wound on the voice coil of a cone driver, and it doesn't have the inductance of a coil, so Maggies are an easy load for the amp.

I think your problem is speaker cables. I had that problem a while back.