Help me in setting my amp gain?

First off the Hz (hertz) is the SI unit of frequency defined as the number of cycles per second,as for KHZ (kilohertz) is the same but One kiloHertz (kHz) is equal to 1,000 Hertz (Hz) or 1,000 cycles per second.

as for sub setting normal means your speakers are in the box the right way ,Reverse means their put on opposite with the magnet sticking out pick one of those will help, pick 65Hz to !150hz its up to you the bigger the amount of hertz the more your sub will move and sound but as you go up you begin to hear the highs on your sub (the lyrics of the singer) i recommend 125 Hz it gives you the optimum bang really loud adjust the -6 to +6 as you move your stereo volume so you wont kill your speakers as the volume goes up the number goes down (by the way you should never go all the way down to -6 for more vibration you can feel )

Now for your mid and highs look at their specks and put he frequency to match them or a bit lower than recommend like if they say 20hz-25000Khz put the frequency for highs at 24000Khz or less if you don't want insanely loud highs i recommend it a bit lower because you can blow your speaker tweeters >.> i know this frist hand s for your mids its pretty easy to adjust it after you got your lows and highs and that's entirely up to your taste and music preference :D good luck if you need me to explain anything just ask :P