Some speaker cables produce lower/higher volume?

No, but odd order harmonic distortion is perceived by the ear as a loudness cue. The amounts of distortion at higher orders may be very small but you will readily hear it. "Turn that down" can often mean turn down the distortion.

You should use an SPL meter to measure the difference. Please report back.

Did you pull out the db meter?

yes, due to what counts the most: gauge. A good experiment is comparing canare 4s11 against canare 4s6 for example... same wire, different gauge.

I have demoed many speaker cables including clearday and those gave a midrange suck out which forced me to turn up the volume alot. The bass was more pronounced than many others I did not like them. Also one of the cables I had tried Granite audio which was a very good cable however all frequencies were louder than any other cable I tested. Over 15 different names. So your not trippin.