Ok, this has been happening for quite a few months now, but I've been putting off since I didn't have the time or cash to try and address it.

I have Focal components in the doors and coaxes in the rear, all powered by an alpine amp, and a Kenwood HU. I've been having a problem where the passenger-side speaker will keep cutting out when I hit bumps in the road, but if I turn the volume way up, the speaker kicks back on. It seems to be getting worse, where it will now constantly kick in-and-out (depending on volume). All efects are FAR worse when using the radio instead of a CD or my iPod, almost sounding like a badly blown cone.

I figure it's probably not a loose where, otherwise turning up the volume shouldnt fix the problem. I'm not sure if the channel on the Amp is blown or not, as I figure it just wouldn't work at all if the channel was shot. I'm not sure if it's the speaker or not, as if the cone was shot, I would imagine that turning up the volume would just make it crackle worse. THe only thing I have left as a guess is the HU. Has anyone experienced this kind of issue before or heard of it? I'd like to try and find a good starting place, before I start replacing things, as that will get very expensive..

Thanks!

 

I had this problem in another car, only my tweeter kept coming in and out. What the problem was for me was there was a loose connection where a piece of the solder came loose and was dangling on. I think what happens when you crank the volume is the speaker gets more vibration causing that loose connection to bounce back into place. Hope this is your problem as that is a cheap fix. Seeing as how the speaker still works, it must be getting power from either your amp and/or headunit, so I would rule that possibility out. Might just be a bad fuse somewhere or a loose connection.

 

If your amp has a channel blown it wouldn't cut in and out. It just wouldn't work. Easiest and cheapest way to check:
Switch the left and right outputs on your amp. If the cutting in and out is still on the same door, then its the speaker. If it swiches sides then its the amp or somewhere before the speaker.

If the cutting in and out changes sides then put the outputs on the amp back to the original configuration and switch the RCA inputs on the amp. If the bad door stays on the same side then it's the amp. If it switches again then the problem is before the amp.

Follow the same idea all the way to the H/U and you will find out where the problem is and then you can address it. While tracing everything back you may just find that one of the wires was loose and be fine.

 

My HU did exactly the same thing. It isn't a Kenwood, but an Alpine. At lower volumes, it would cut out and make the speaker sound blown. Crank up the volume and all of a sudden it would work while scaring the crap out of me (loud burst of volume kicking in). I did exactly what ZNizzy mentioned and started switching wires around. Tracked it down to the HU and had it repaired. From what I was told, one of the solder points internal in the HU where the RCA jacks connected had come loose.

Good luck!