well now both of them play. but at times, one side will cut off. sometimes it plays really distorted, all kinds of crap is going on. i already have a pioneer that came with shitty preouts. my front channel preout gives out massive alt whine, as well as my sub preout. so i have my front stage on my rear HU preout. only one that works. i even tried using a LOC, by the amp, and at the HU. still had alt whine