I completely disagree that cables do not make a difference.
They make as significant difference as changing a major component in the system, speakers or amplification.
If your system is transparent enough, you will easily hear enormous differences cables bring. Whether good or bad, is dependent on the synergy between components, and ultimately on your taste.
Point and case:
Just today I tried two completely identical power cables on my amp, PS Audio Plus, one being brand new one, and one being used (burned in).
The difference was unbelievable (yes, power cables make huge difference, not to mention changes interconnects or speaker cables make).
Although more money does not mean better cable, in general it is applicable.
As good as cables from Signal Cable may be (since someone mentioned them), they are certainly not a match to let’s say Acoustic Zen cables.
I have heard speaker cables from both manufacturers and it is absolute nonsense that there is no difference, the difference is enormous.
However, if in your system you do not hear the difference, it does not mean there is not one, it just means that your system is not transparent enough to let you hear it.