I have a 4-channel Class B amp that's rated at 60 watts/channel @ 4 ohms. It's pushing two 6.5 inch infirnity reference speakers up front and JL 8 inch W3 woofer in the back (bridged).

My local installer said I could run this easily with 8 guage power wire and ground. That's what we did, but I also have a parallel 8 guage running for a powered sub I was going to use (but didn't like).

Is 8 guage OK to run this amp?
Should I use both 8 guage wires?
Do 2 8 guage wires roughly equal 1 4 guage?

 

8 guage is fine for that amp. Any more draw and you'd need to upgrade. A Pair of 8 guage is equal to 6 guage.

Problem though with 70% of the 8 guage wiring kits out there is tha it's really 10 guage with alot of rubber to make it look bigger.