I bought a deck last week. Its an alpine 9833, I had the 7894 before that. I'm running two 10s in the back and when I plugged the new deck in the subwoofers are picking up the engine revs. And when I'm driving and come to a stop the subs will beat even if the music is turned off. I tried plugging the rca's into the front and rear preouts and they don't pickup the engine noise. I'd leave them like this but I still want to be able to control the sub output level.
At this point I'm pretty sure its a malfunction with the deck but want to ask around to see if anyone has had this problem and may have another solution rather than to send the deck back to alpine.
Did you reset the amplifier input gain when you changed the deck?
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Support the12volt.comThe only thing I tried was to turn down the gain all the way then turned it back up but it still picks up the engine noise.
Any time anything changes in the signal chain, all amplifier gains must be reset.
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Support the12volt.comI never found any reset button the amp itself just the gain knob. Wouldn't that carry across no matter what the input was (i.e. sub preout, front, rear)? Cause this only happens when its plugged into the sub output.
Are you useing the Hi Inputs?
If you had it with the rca's you'd need a ground loop isulator.
Try earthing the H/U & the Amp at the same point! Sounds like a pain: But try it with a scrap bit of wire.
Failing that move the earth point somewhere else.
Sorry what's the Hi inputs?
I'm starting to believe that this is a problem with the head unit itself. I pulled out my old deck (Alpine) which has the same specs as the new one (Alpine), the only difference between the two is that one is the 03 model and the other is the 04 model and the screens are different. Both are V-drive 60w x 4 with 3 4v preouts for Front, Rear and Sub. When I plugged my old deck back in and ran the rca cables from the sub out straight to the amp it works fine, but the new deck picks up the engine noise when I'm running the RCA's from the sub out on the new deck to the amp. The amp is an 03 model Kenwood 350 two channel that I have bridged into one channel and running the two 10s wired for 2ohms. But I don't think the amp has anything to do with this since the output on the new deck is the only time this problem comes up.
I'm probably going to have to send it to Alpine.
High inputs are only on certain Amps...if you have a stereo with no out-puts you can utilize the speaker out puts from the H/U to drive an amp / Especially useful for O/E H/U's...But you have outputs so 4get it!
You may want to try a 'GROUND LOOP ISULATOR' It plugs into your RCA's & acts as a noise supression filter.
There may be a potential difference within the equipment or the way its wired.Where is you Amp earthed? make sure its clean down to the metal no paintwork + You know some RCA's have a small wire running between them, it can be used to ground the amp & H/U together.
I will third that ground loop isolator. They do wonders for engine noise...