Mike, thanks for your comment.
Getting back to speaker cables, it occurs to me that what I said about connector-related impedance discontinuities in relation to digital cables may have some applicability to speaker cables as well. Speaker cables will to some degree act as antennas, picking up Radio Frequency Interference from various sources, such as nearby cables, power cords, digital components, switching power supplies, light dimmers, fluorescent lights, possibly wifi and even radio stations. That RFI will presumably be at frequencies that are too high, and at amplitudes that are too low, for the speakers to reproduce it and for our ears to hear it. However if the amplifier uses feedback, and if (as I would expect to often be the case) the amplifier's output impedance at RF frequencies is significant, some of that RF energy will be introduced into the feedback loop. Non-linearities and intermodulation effects within the amp may then result in that energy affecting sonics at audible frequencies.
And the magnitude and frequency characteristics of the RFI that is injected into the feedback loop can be expected to vary to some degree depending on the differing impedance discontinuities and mismatches at the two ends of the cable.
The magnitude and frequency characteristics of the RFI that is injected into the feedback loop might even differ significantly depending on the exact physical placement of the spade lug or other termination on the binding post, and/or its positioning relative to nearby metallic surfaces on the amp. As I said early in this thread, when hard to explain and/or seemingly implausible phenomena are being addressed, multiple back and forth comparisons are called for, to be sure that the observation is being attributed to the right variable, as well as to verify that perceived differences are perceived consistently.
Best regards,
-- Al