I have a Pioneer DEH-X7500S headunit (4V preouts), an Hifonics BRX1100.1D and a Sundown SA-12 D2. I was wondering what is better to set your gain right:
1. Turn the subwoofer level output up on the headunit (maximum for example, which is +6 in my case) to use the full potential of your 4V preouts and minimize the amplifier work (lower gain), and then adjust the gain from that to match the desired voltage with a DMM (28-30V in my case).
2. Keep the subwoofer level output on the headunit at 0 and turn up the gain on the amplifier (higher than option 1 for sure) to match the desired voltage with a DMM (28-30V in my case).