Do speaker cables really make a difference ?

They do make difference, but if compared 10k Nordost with lamp cord, you really wouldn't know what sounds better if blind A/B. 

Try doing a blind A/B with 100 of your favorite recordings and you may hear a difference.

@dweller you can multiply it by another 100 -- make it 10,000 as in my case, but the fact will remain the fact -- you won’t know which one sounded better on which wire and on which record $10k or $10.

@whipsaw +1 on Audience. I also use AU24SX speaker cables terminated with rhodium plated spades that replaced a much thicker Purist Aqueous 20th Anniversary which was a very good cable. Thickness of speaker cables is irrelevant if the materials used, design and implementation are done right. 

@rsa

Depending on your system and your ears, yes, you can hear a difference. You don’t have to spend a fortune. Many people are very happy with Blue Jean Cables.  As other correctly say, the size of conductor, which equates to a low resistance, is important.  Capacitance is not as big an issue in speaker cables as it is for line level interconnects.