I'm looking at subs for my 2 door x. I found a single 12" Polk 4 ohm sub and a 12" enclosure. I'm looking at Amps also, any suggestions? And I was wondering if I can run a sub off my stock head unit? I have the touch screen my gig with nav and the works. I will eventually get a 4 channel amp for my Polk speakers. So main question is, "can I run a sub, and a 5 channel amp? Or would it be better to run a sub, a mono amp, and a 4 channel amp off the stock head unit?" what would be a better choice? And would either work with the stock HU?"
Kind of confusing. Sorry guys. Any replies appreciated, thanks

 

Might want to try the electrical light sound section.

 

Depends on if the head unit has Any RCA's might want to look at the back of it and see, do you plan on running new wire to all of your speakers or using the stock wire? If you head unit has RCA's look and see if it has front, rear, and sub if not you can get by with front and rear, also I have never hooked up an amp this way but you can run the speaker wires to a amp instead of RCA's or at least some of the older amps could.