Pro tip: my brother in law said to leave slack loops behind the TV, and now I'm not sure he was right
He said tight coils cause interference so I left 3 feet of loose cable bunched up back there, and my wife says it looks worse than before. Is a little slack actually better, or should I just zip everything tight and be done with it?
Laughing at the image of your wife staring at a rats nest of cables behind the TV while you defend your brother in law's honor. Here is the thing, a few loose loops won't hurt anything, but three feet bunched up is just a dust collector that looks bad. Tight coils can matter for some stuff, but for a normal TV setup you are not running a radio station, so the interference thing is mostly a myth. Zip ties or velcro straps are your friend here, just keep the cables from pulling tight on the ports and you are fine. Tell your brother in law he owes you a beer for the grief.