After more extensive listening, I've concluded that grounding the new enclosures to the Meridian G68 resulted in sound that is slightly worse, particularly in "listening ease" at loud volumes. Here are the 3 arrangements I've tried:
1. Enclosures grounded to ground rod.
2. Enclosures not grounded.
3. Enclosures grounded to G68.
I can say with some degree of confidence that (1) and (2) sound better than (3), but I cannot say with much confidence whether (1) sounded different from (2). So maybe the ground rod is adding nothing other than additional risk.
As for why (3) sounded worse than (1) and (2), I don't know what to say. Maybe grounding the enclosures to the G68 made the enclosures act like antennas collecting RFI, and that RFI was then transmitted into the G68? I don't know. I'm out of my depth. Maybe someone has a theory.
bc
1. Enclosures grounded to ground rod.
2. Enclosures not grounded.
3. Enclosures grounded to G68.
I can say with some degree of confidence that (1) and (2) sound better than (3), but I cannot say with much confidence whether (1) sounded different from (2). So maybe the ground rod is adding nothing other than additional risk.
As for why (3) sounded worse than (1) and (2), I don't know what to say. Maybe grounding the enclosures to the G68 made the enclosures act like antennas collecting RFI, and that RFI was then transmitted into the G68? I don't know. I'm out of my depth. Maybe someone has a theory.
bc