The number of strands in the cable make no difference... called "the skin effect"... and 14ga. romex (in wall mains cable) and 14ga stranded would be the exact same.

Also, the listening levels don't make a difference either... but the length of your runs do.

Copper quality and # of N's... wow... 13N OFC? That's 99.99999999999% free of oxygen! "Most people" won't hear a difference between that and 2N OFC? Most people in this case is 100% of all listeners.

Bren R.