We all experience what seem to be 'synergies.' It leads to many suggestions of what might be worth a try.
Based on what I have heard and learned, I do not think this is the case with Morgoth's speaker wires from Audio Magic.
He reports the sound is cleaner. This is why he also hears the soundstage become smaller. One aspect of cleaner sound is a less 'phasey' presentation. Now, this lack of 'phasiness' always makes the soundstage smaller, precisely because there is less 'out of phase' information delivered (created by many cables). It is that increase in clarity that says one is on the right track.
Then why does Morgoth hear the detail and dynamics also diminish quite a bit? When I have heard the same, I eventually found that first, the wire is actually passing the dynamics more accurately:
Peaks are rising more quickly (Morgoth's "cleaner sound" again being the key indicator) and then decaying farther into the background.
This represents an increase in dynamic range, but because the other wires are actually compressing the dynamics, they seem louder. They are, being louder on the average . This is exactly why studios compress drummers, to 'sound loud and therefore dynamic', hence the Dire Straits recordings that many think are 'super-dynamic'.
Because the average sound level is 'less loud', then the volume should be increased, and the details will re-emerge. Then, start listening to many recordings non-critically, learning to trust one's emotional responses to favorite selections. The subconscious will not lie. Try some of the less-compressed jazz and pop recordings of the 1950's and early 60's, such as by Louis Prima and Keely Smith or Oscar Peterson Trio. Classical recordings from that era also reveal much.
Then switch back to the other cable after a couple of weeks. If what I suggest is true, then the music will become a) louder, and b) more boring.
Some would resist any suggestion to turn up the volume. I did for many years, knowing that there could never be enough difference in loudness from resistive losses in various cables and wires to warrant changing the volume knob's position, and that is true. However, listening to a wide range of music and allowing my subconscious to participate revealed what was going on.
I would be interested in the outcome of Morgoth's and anyone's listening tests. I hope my suggestions help.
Best regards,
Roy Johnson
Designer
Green Mountain Audio