ok....I used to be big into subs and amps when I was a teenager but I have fallen out of touch with what it what these days. I have a Pioneer deck with Infinity Speakers in the front and rear. I am looking to do one sub with an amp. I really don't want it to be super loud from the outside, but I want it to sound really good on the inside. I've looked at the single boxes for under the rear seats and the console box. I'd like to hear what you guys think. I pretty listen to hard rock and metal. Also, what size sub and brand. Which amp? And is there anything else that needs to be added to the sub box other then the speaker itself> ie.....crossovers etc......