Surf city garage beyond black is the best product I have ever used and I have used alotttt of different products.
2 Sundown X10's in 2.5cuft Net tuned to 31.65hz
SKAR SK-1500.1d, SKAR SK-85.4
Lots of Audio Technix 0 gauge
XS Power 1200,XS Power 3400d
I murder lowssss