After i installed an Alpine head unit (replaced the Blaupunkt) i picked up a very noticable alternator whine.

I used to have a bit of whine when i first installed the balupunkt and the amps. I used a noise power filter into the amp which knocked the whine back to quite tolerable ... I used common grounds, ran rca and speaker cables away from power cable, etc. I did the ground kit also.

So anyway - i found a scoshe rca cable noise filter - easiest thing in the world to install and made a huge reduction in the noise. Back to better than before.

sweeeet.