number one priority: just make sure the voltage doesn't go above the rms. so if you have a amp with a bigger rms than subwoofer, set max voltage to subwoofer. If amp is smaller rms than subwoofer, set maximum voltage to amp. v = sqrt of max rms power * total ohms of subwoofer. this will get you maximum voltage. voltage is ac, use voltmeter, and touch positive and negative terminals of subwoofer. BE CAREFUL THO, AC KILLS. DON"T BE STUPID AND TOUCH THOSE TERMINALS WITH BARE HANDS WHILE MUSIC IS PLAYING. I did that once on accident, not fun, long story short... anyways, I usually have a multimeter already attached to my subs (everything insulated, and wrapped with electrical tape) that way I can gauge what value my subs are hitting. Just make sure you don't go above the rms max voltage. if you do, you can get distortion or a fried subwoofer... just keep an eye of your voltmeter when the bass starts hitting hard lmao.
here's my setup:
I have m350 amp sound ordnance class d
dual terminators 400watts rms 12"
impedance: 2 ohms
since amp can only do 350 watts rms, that's my max voltage...
V = sqrt of 350 * 2 ohms
~26volts
easy, now I have my value to NOT go over when my subs are hitting. If I were to increase my volume above 26 volts, clipping could happen. clipping = dc = higher chance cooked subs.
and to really answer your question, when you start fiddling with your amp settings, it may increase voltage quickly and cause harm to subs... like bass boost. try to not touch that because that can potentially ruin your subs lmao, unless you're sure you need it......
hope this helps...
and if im wrong, anybody correct me, im still new to all this, but so far, this works for me!