since this is new to me i do need help

what changes when i turn on the frequency screw? 50-250hz (if i set it to 50ghz will the sub only play tunes 0-50hz? (like a hpf/lpf)

and gain screw how to set that properly? (will the sub damage if you set the gain to low?)

nvm i think got it working props now (it sounds good)

you dont want to high of freq going through your subs sett it to like 80 hz, and how to set the gain properly is play your music at the volume you would normally play it at, then turn the gain up untill you start to hear a little bit of distortion coming from the subs, then turn it back just a notch. distortion ruins subs pretty fast.

well i got a bass tester disc with low hz sounds to set the gain with 25/30/35/40/50hz 10 sec in each

i can put the gain on 80% without distortion but i play like Bassotronics - Bass, I Love You it distort after 60% at 40% sound on headunit

i guess you cant get the gain to low?

what kind of amp you have? and do it like this. play your music at volume you would normally listen to. then adjust the gains and freq, hard to tell whats happening when your volume is low.