Hate to repeat the preceding post, however it's a bit different of a problem. Same overpowering annoying sound coming from the XM9s. See boat and audio description in my signature. When the engine is not running, system sounds great. Crank the boat, terrible whine coming from tower speakers only. I can turn them all the way down, DC the RCA cables, the whine is still there. Only way to get it to stop is if I pull the fuse on the Exile amp.

Brian, if you read this, can you chime in also?