Thanks for the information and suggestion. I am first going to install another 0 AWG set of cables to see if this improves performance, before considering the acquisition of another amp.
I high pass the amp output from 35hz. The Magnepan MGIIIa's are flat to 40hz and fall off from there. Moreover, the bass Mylar panel is a large area with very little excursion. Consequently, perhaps the control of this driver is not as challenging as a cone driver with a long excursion attempting to reproduce sub 35hz frequencies. Is the optimum DF as critical with this system?
Frequencies below 45hz are fed via the pre-out to a Velodyne FSX-12 that is "Servo Controlled" to limit excursion. The pre-out and powered outputs includes Devialet's SAM software designed to limit cone breakup. The speaker cable in this unit is probably 14 inches long. I can not find a DF spec for it's A-B amplifier.
Does any of this additional information alter your opinion of the ideal cables for this system?
Notwithstanding the fact that DF is supposed to benefit frequencies below 85hz, my observation is that adding 2x0 AWG speaker cables greatly improved mid and high frequency resolution. This may be the result of the attenuation of bass and mid-bass excess excursion (boom).
Current bass control sounds tighter and realistic. It's measured in-room response is flat.
Unless you advise otherwise, I am willing to invest another $67 to see if it can get any better. Plus, I like tinkering. I will let you know if the next experiment yields diminishing returns.
Cheers
J