thought I was immune to noise but ...
 

since day 1 I installed my system never had any noise whasoever. For the last few weeks I started hearing a little bit of high pitched noise coming from speakers. I thought it was more or less ok but... I also started hearing a very low frequency hum when I put the car in drive or reverse but once rpms go up a little and I start moving the low freq hum goes away. I thought it was my exhaust or something... and then when the engine is on and volume on the deck at zero I can clearly hear the subwoofer humming but not as loud as when the car is in drive or reverse. And I am not 100% sure on this one but I think I am hearing it randomly poping (not loud) a little bit when playing music. Weird stuff... :dunno: I didn't start checking everything yet but how the f#$% would it appear all of a sudden?? I recently changed to a 12" ID sub running at 2ohm on alpine mrd-m605. I have a cheap line driver, maybe it is starting to go therefore bringing noise to the system. I thought I would never have to touch this stuff again and just enjoy the music but looks like that's not the case.

Anyway, did anybody have similar symptoms?

i would say you have a bad wire as a -neg-

This is fairly common. Over time your grounds corrode, your battery connections corrode, the battery water levels may drop, the battery itself is older and less of a filter. All kinds of nice things.

Go through your system cleaning all of the heavy cable points: amp grounds, battery connections, and make sure the battery is topped up (if it is a servicable type)

ya totally sounds like a ground prob to me'

and now I'm screwed
 

well as I was driving yesterday I hear my speakers make scratching noise all of a sudden and then boom no sound, only the subwoofer going. I opened the trunk and noticed the ground cable came off the speaker amp (Alpine MRV-F540). It didn't really look like it coud've touched the positivie when it popped off. I turned it back on and sound is there and as a matter of fact the noise isn't there anymore as well. So I was happy and all that it was as simple as that. But.....

Here's the problem. I turn my deck volume up over 14 (out of 35 on an Alpine CDA-9857) and the amp goes into protect mode. The light turns red on it. I turn the volume down and sound is back and light is blue again. I noticed this is happening on lower volumes with songs that have more power to them. And when music is playing before shutting off it comes from all 4 channels.

Does my amp need repairing now? Is it blown? :(