I believe so. I've heard many stories of this happening, but haven't experienced it myself. Could produce a ground loop I suppose. Try to isolate it with rubber washers or something.

 

maybe ground loop? I dunno. Super easy to tell. Pull the amp up, sit it on a cutting board, see if noise goes away.

 

unless the amp is physically shorted to its case (which I believe they are NOT) it shouldn't be an issue....

 

Most amps have at least their primary side ground connected to the case. In many amps, you'll see a little jumper connected to the hold-downbar over the PS Fets or the chassis. It's just a method for creating a quasi-Faraday shield from the chassis to reduce RF emission egress. It seems that this really only happens with good quality amps that don't ground the RCA jacks to the chassis (ie: primary side) either directly like old Pyramid amps, or through a 10-150 ohm resistor like many lower end amps throughout car audio history.
An amp that advertises a balanced or "quasi-balanced" input is a good bet for low noise amplification. Everything else...well, you're taking chances that your trunk ground is as clean as that of your source device.

 

Sure can. My soundstream amp did this.

 

yep, ground loop noise

 

I did this with slash series Jl's and it was not good...I had noise through the Audiocontrol Matrix that I was using(eventually broke) and through the amps....

It drove me crazy until I did a new amp rack. If anything metal touches anything metal on the amp...there is a HIGH possibility for noise.

 

The whole concept of grounding the amp case is based on an AES document from a long time ago. actually all involving ways to minimize ground loops and noise interferrence, as my buddy tells me.

As an alternative, you can do what a local to the central cost of california did. He pulled the amp chassis off the metal frame for an install, then yanked on it while it was playing till the ground fell out. Being shorted to the RCA cables like all phenominally built RF amps, the amp then tried to pull 800 RMS of bass through the RCA shields which were connected to his pioneer flip face TV screen cd player.

First time I ever heard a radio after the micro fuse blew. You might imagine the guy was a little upset.

 

Quite a few designs tie the secondary (floating ground) side of the amp to the chassis. Soundstream did this in their REF and Rubicon series amps. Kicker did this with their ZR, ZX, and DX series amps. Fosgate has done this forever...

When you bolt the metal case of these amps to the chassis you create an immediate ground loop. That is why a few of these manufactures supplied plastic bushings that snapped into the mounting feet. The bushings isolated the screw body from the amp chassis.

My recommendation. Bolt a piece of wood to your vehicle, then secure the amp to the piece of wood. Problem solved. Just make sure the screws securing the amp are not long enough to go through the wood and make it to the chassis.

Ge0