New Car - line noise
 

I plan to swap my DD center console and pioneer avic-8200nex unit over to the new car soon from my 99 coupe. I've been running the Avic without and amp and using two-way wired speakers (JL Audio C2-350x and C2-650X) with factory Bose which has been crisp and good. But the new one has a 5 channel amp and certainly puts out some noise!

However, as it sits currently the new (to me) '03 Z with its very basic JVC single din head unit has what I consider to be a lot of line noise. This is not in line with RPM, and in fact it also exists when the engine is off, so it is not a question of shielding the ignition wires better. No matter the source feed... usb, radio, bt.... this noise exists. A low static.

Can someone point me in the right direction on what to check out and or do to alleviate this issue? I don't yet know what speakers are in the car, but I was told they are Polk in the doors and rear sides. I forget what the tube in the trunk is. The amp is a Kenwood X700-5. Head unit is single din JVC offering bt, usb, aux.

I hope to resolve the problem prior to or during install with the Pioneer.

Pics of current setup which I love:
Attachment 48348350
Attachment 48348351
Attachment 48347234

The high noise floor could be attributed to a couple of things:

1. the gain is cranked all the way up on the amp
2. the JVC is just noisy
3. the amp is just noisy
4. there is a poor connection between the amp and the head unit

That kenwood shouldn't make much noise. I'd start by checking that the RCAs are tight on the amp and headunit, and then re-set the gains to see if that helps with the noise floor issue. There are several ways to set the gains, but I would just use test tones and my ears as it will give you quick results without the need for a more complicated set-up.

https://www.crutchfield.com/S-8JFfdo...fier-gain.html

I agree with Dave. Most likely the gains are not set correctly on the amp and are turned up too high.

+3. Amp gain too high or....
poor wire connection, quality, or separation.

But the dash looks cool.

That's the one I built - that one works. At least, it did.... then I pulled it apart to transfer to the new car. And then yesterday the new car broke down (Day 2 of ownership) and I am trying to figure out what the noise is. That is, it still ran but it began making a metallic noise in sequence with RPM. I checked the valvetrain and it appears intact on both sides - no metal flakes or chips/debris, and nothing visibly anything other than perfect. I changed the oil, again no visible debris or flakes. I changed the passenger side plugs and nothing out of the ordinary. Will get to driver side tonight and see. From there, I will test fire it briefly if nothing is seen. Fingers crossed.

Is it a tapping metallic sound? A crunch? Whirl? Buzz? Metallic is only a "sound" when you add an "a"...then it becomes Metallica.