Using solid copper Door Bell wire as speaker wire.

Tried it many years ago.It works, and there is a nice effect to the treble using it.You lose in the bass department, stranded works better.

It's cheap,and compared to other cheap name brands at the time, I liked the what the solid core did to the sound.It seemed to clean up the top end.

I can't recall if I ever had speakers back then that were bi-wireable, but you could try the bell wire for the top end and stranded for the bottom.

If you saw what that Door Bell wire looked like under an electron microscope you would gag. :) lol.

People cannot hear the difference between cables for many reasons. It could be their system that is not resolving enough, could be their hearing instrument or just negative placebo effect since they often strongly believe, that cables cannot sound different. Often they feel defensive about inability to hear the difference (if I cannot hear, nobody can) and post questions about lamp cords or thermostat wires to find confirmation from the other people. Since wire is inexpensive just try it - If it sounds good to you then use the cheapest one, even if it is barb wire (be careful). No right or wrong here.