Ok, this is kind of odd. I have a killer setup (Boston Acoustic Pro components hooked up to a JL 300/2, 12W7 hooked up to a RF 1001bd monoblock amp all running off of a pioneer premier 860, an older model HU). Anyways, my CD, FM, and XM music ALL play at a lower volume than when I first hooked it up. I am 99.9% confident that the amps and speakers are all still good. I have noticed my HU has had some issues (sometimes the face won't open, there are 2 solid lines in the display that won't go away that shouldn't be there) but nothing that makes you think it is having an effect on the audio, except the decreased sound. The songs still play clear and no distortion, anything like that, just lower volume. Can the HU be causing this or something else? The reason I don't think it is the amps is because that both the sub and components play lower than what they normally did. Thanks for the info, and if it isn't infact the HU, what do you think it could be?
