Im going to be upgrading from the stock head unit to an aftermarket, however, i had a question. I basically want a radio that has an option for subwoofer so i can turn up and down the sub without affecting the door speaker's bass level. What option would i be looking for when comparing stereos? Is it called sub pre amp output?

 

3 sets of outputs (6 total) just about any unit with a designated sub set will have this

 

thank you for your help