It depends on how much current your amp will draw. If you're amp draws 10 amps, it will drop voltage 2 volts with .2 ohms. (V=R*I). So at the moment the amp is pulling 10A the voltage will drop down to 12, assuming 14 to begin with.

I would try to shoot for something better. Maybe even put some dielectric grease between your body and ground washer.

 

If he's going to running a high quality amp, the voltage drop wont matter. higher end amps are rated at 12.2V rather than 14.4V or 13.8V. As far as dielectric grease... all that does is protects from corrosion... it will add some resistance. Dont know how many light bulb sockets I've had to change in the last 5 years because people put bulb grease (dielectric grease) in them.

 

True, but my example was if his amp only pulled 10A of current. I would almost guarantee it will be pulling at upwards of 30amps, especially with 5 channels.

Didn't know that about dielectric grease.