2nd Question Bi- Wiring

[Barry]

It was a gimmick and selling point for the speakers and cable. Few speakers now provide this 'facility'.

Certainly it was de rigueur for a while, but there are modern speaker designs which still offer the 'facility'.

[Lawrence001]

There could be advantages, but to make a fair comparison you should compare like with like, including on a cost basis.

So if you have a biwire cable, compare it connected as biwire, to both cables connected in parallel to both terminals, that way you don't have a guage advantage to skew the results. (You can also try a single run too just in case it works better, which it can.)

And if you want to compare bi wire to a single wire cable then they should cost the same, meaning the single wire will be much better quality being twice the price per metre.