Hissing sound after installing aftermarket double din?

[chat2tristan]

Rack your brains I need some help!

 

I just installed a JVC KW-230BT into my 2009 Subaru Legacy Sedan with factory Harmon Kardon sound system in it using METRA Harness# 79-8901. I twisted, soldered, and heat shrinked each individual wire.

 

There is a low volume hissing sound coming through all the speakers at the same time and its driving me nuts! I used the balance and fader to make sure each speaker was functioning properly and other then the hiss each speaker works correctly. The first thing I thought of was maybe a bad ground on the head unit so I tried a direct bare metal ground instead of using the harness and that made no difference.

 

The sound only happens when the volume is above 0 and does not increase in volume as you turn the volume up it is just a constant low volume hiss. If you turn the head unit to 0 volume the noise stops. It doesn't matter what source you are using either.

 

What would cause this? Signal from the aftermarket head unit to the factory amp issue? How do I fix it?

[Shadow_419]

Assuming you have your high level outputs from the new radio connected to the h/k amp, you're probably hearing the noise floor of the radio being amplified again by the h/k amp.

[MaasaiWarrior]

re-do all I mean all your grounds throughout your audio system, it's the same thing if you get a buzz on a home amplifier