issues with aftermarket head unit

[jpdyck]

Hello,New Vibe GT owner - we purchased a 2003 Vibe GT a couple of months ago and just purchased a JVC KD-G510 head unit at Best Buy. Best Buy installed it for us - everything works fine except for two things:1. Volume seems high (i.e. at volume 00, no sound - at volume 01, volume is louder than what you'd expect)2. Noise - there is a fair bit of background noise. This becomes unnoticeable at higher volumes, but it is annoying.The installer at Best Buy thinks there might be issues with the fact that we are still using the factory amp and speakers. I would have thought that this wouldn't be a problem and other posts on this forum seem to indicate that people have done this before.Does anyone here have any thoughts?Thanks in advance.....

[ragingfish]

Installer likely hooked up the high level output of the head unit to the amp. This is effectively double-amplifying the signal. Which is why it sounds like a$$. He needs to put a line level converter inline to bring the noise down to line level. Don't let him hook up your RCA outs on your head unit to the amp. There is a horrible noise that develops when doing that, no one has been able to resolve it. You're better off with new speakers and amp, but if that's not in your plans, then you need to do the above.

[russ257]

agreed get a scosche line level device and it will fix that

[mcgusto82]

if your radio has a front and rear pre amp connectors, i'd use those just use a lineoutput converter on them to turn them into speaker wires and usable on the stock amp. or simply rewire the speakers without the amp.either way. i haven't had any issues with my sony. i've got the stock amp connected and running.