I have received zwe these devices and both had the same defect. At higher bass caught one of the boxes on to knartschen or rattling (chwer describe) Of course, I've been trying to figure out what it was, so I have both times reversed cable Red cable in the White Output and White Output cable into the red, then came out that always knartscht the box or rattle when the field is in the Red Output. This can be annoying when loud music ziemich therefore, I have both devices zurückgeschckt and get my money! Great service from Amazon. I can help you with my review I hope