I think some cables sound different to each other.....but the trouble is so many sound the same.
Differences are usually subtle, but some silver cables sound too sharp and some cables definatley sound a bit dull, it's more about fine tuning than ' night and day'
Cables are dictated by resistance, capacitance and impedance. Its basic physics! Unless you play around with the load on an amplifier by introducing something in-line, all cables will react in the same bloody way - allow the passing of electrons! Thats all they do. Bad insulation will introduce interference from radio frequencies or the plug may be an odd resistance but then that is a fault
and not a sound characteristic.
Try doing a blind test, you will not be able to tell what is what. I had 8 years of this, moderating a forum full of wannabe experts who believed nothing more than the bloody magazines. The company I worked for voided the warranty if anything other than a standard power cable was used. The company sold interconnects from Belkin for a fair price and that was that, no daft promises, just quality materials tested in F1 race conditions and perfect for 'Hi bloody Fi'.