I am currently working on a purchase for a new subwoofer to add to my factory stereo. I do not have dsp. I went to an audio store, and the guy recommended 1 12" Punch sub. I do not remember the amp, he recommended, but total with all wires, enclosure box, amp and install was $350. Is a good deal?
http://www.audioexpressusa.com/products/?id=118