The only way to insure your cables are not exposed to vibration is to not use the speakers. Otherwise, as long as all your other cables are sufficiently shielded it simply makes sense to keep AC and speaker wires away from signal cables, with the speaker wire visable so you can look at how pretty it is. Keeping speaker wire off the floor can be useful when vacuuming the dust under it. Or run the speaker wire through a hole in the floor suspended in the basement ceiling (or lower floor) air...this is very useful for hanging laundry or drying plants from it as long as your laundry or drying plants don't vibrate.