From: Need Help Wiring a 2 0hm dd9515g down to 1 ohm

[TonydaBully 0]

Just be careful, gains low doesn't necessarily mean the sub isn't getting much power. Gain setting is completely dependent on the input voltage from the head unit. If you have 6 volts coming down the RCAs, chances are you need the gain all the way down. I'm not saying you're wrong in turning it up, just take note if the sub is stressing with the higher gain setting.