Doug, chime in here and give us your power-wire wisdom.


You are right on the ragged edge of adequate wire size.

It isn't a question of how many speakers and what size speakers you are driving, but how many watts of power your amplifier can put out, the efficiency of the amplifier, and the length of the wire run to the amplifier.

A worst case scenario might be that you are running your amp at max output -- 640 watts peak (320Wx2 bridged 4-ohm) with a 15 foot wire run, and assuming that your class D amp is running at 80% efficiency. This would put you over the maximum acceptable 1/2 volt drop through the wire run. The most you could run would be about 580 watts under those circumstances (that would give you a .49 volt drop :-)

However, you aren't likely to be running your amp at its max output, but at considerably less than that. But to negate that to some extent, amplifier efficiency drops as the gain levels are reduced.

For a bit of education on this topic, go here. This is beyond question the best website I have ever seen about car (and to an extent, home) audio. It is well worth spending 20--30 hours there. I have done so, and have learned a LOT. (Go to the bottom of the page linked above, and follow the link you find there to the home page of the site.)

Anyway, it is not likely that your car will erupt in a ball of flame and shrapnel because you are using the 8-gage wire. But 6-gage would have been better. 4-gage perhaps a bit of overkill, but always better too much wire than not enough!

tanstaafl..

"There Ain't No Such Thing As A Free Lunch"