I had 1/0 gauge power and ground wire directly to the amps, no distribution blocks. Each amp had its own Power, inline circuit breaker, and ground to the batteries. The Speaker wire was pretty dang thick, I dont remember off the top of my head what guage it was. The Sub was wired in parrallel and is a D4 so. 2, 4 ohm voice coils wired with + to + and - to - should be at 2 Ohms.

I just assumed the inside of that cubbie with no air flow is just way to hot, especially pounding music for hours at a time.