I have two subs. A 12" Kenwood and an 8" Atlantic Technology. My receiver is the Outlaw Audio 1050. Since the 1050 only has one sub output, I'm using Y adapters to feed the LFE signals not only to the two subs but also to two RCA cables which in turn go into an old receiver's CD inputs that power some bass shakers. I noticed this hum coming out of both subs a few weeks ago. It's becoming very noticeable lately. Before it was only during quiet passages or when a show was paused (I have Dish Networks' Dishplayer PVR). But now I can hear it all the time. The hum goes away when I disconnect the RCA cables which tells me that the problem is not an internal one from the subs. Any suggestions on how to get rid of this hum?