Ok i have an aftermarket head unit but i was stupid and i didnt get one that came with subwoofer outputs so my question wat can i do to add my subwoofers becuase i was planning on lowering all the bass in my speakers to zero and just letting the subs provide all the bass but now that i dont have subwoofer settings i cant do that so can any1 help me...Thanks in advance

 

you can still do that. I have set up many subs using the rear RCAs on a HU. Set your bass to "0", not "-10". Mine is set to -1 right now.

 

but by doing that im afraid of blowing my rear speakers...do u think theres any chance that i might

 

The sub amp will be the only amp you have in the car? Are you powereing your speakers from the deck. Im not sure if you have the know how or not but you could solder in bass blockers at all of your speakers. If dont already have a 4 channel to power your highs you could invest in one and make sure it has a non fading output, then you could connect you sub amp to the 4 channel