IMO it depends on your system..The more resolving the system the more likely to hear a sonic difference IMO favoring 9nines solid or better...
Stranded vs Solid Copper
I am making a home made outlet box with Hospital grade receptacles. I am hard wiring into the existing outlet box that was poorly installed.(to far recessed) Does it matter if I use solid or stranded wire for the extension wire/cord in terms of its effect on sound? The length is 4’ to 5’