Sonic Diff between a 6' 1.8M & 4' 1.25M PC

Is there a difference in sound moving from a 6' power cable to a 4' power cable? I read somewhere that you only hear that last 6' of cable but would like to understand the concept so I can make a more informed decision. Its a hot mess behind my equipment rack and I would like to clean it up but not at the sake a sonic performance.