Car audio setup help

[mceelo]

I just installed a audio system in my truck and i am trying to set the crossover, amps., levels but I dont have any of the manuals. This is my first time with a crossover, at least one that's not built in to the amp. The amps. also have a crossover. I need to know how to set the levels. i tryed to look for the manual on line for the dhd power cruiser ntx-6211 2/3 way, but had no luck. please help me.

 

[Sean]

What components do you have installed?

 

[mceelo]

I have two amps one for highs and one for lows. Both amps have built in crossovers and i have another crossover wired in as well. It's a DHD Power Cruiser NTX-6211 2/3 way
I have tree subs 2 10" and 1 12" JL audioo all wired together and bridged in a small sealed box each with seperate air space. I only have a 600w amp. ultra linear ul2150
My question is #1 how to set the levels on all the cross overs #2 do i need the extra crossover and #3 should the box have any holes in it. thank you so much in advance cause I dont know what the hell I am dooing.