You are 110% sure?!

Nobody has ever shown that loudspeakercables of reasonable construction is audbile different from 12 AWG cable. From your description there is nothing that support your "110%". To do confidence testing you need to make a blind test. With the help of some friends and random trial. If you can pick correct cable 20/20 then you are close to 100% confidence.

You have shown nothing of this, and thus you claim that there are audible differences, is just something many claim but nobody has ever been able to prove during ≈ 30 years of cable debate.

T