Re: help me build a system for my girlfriend.
i did this same scenario for one of my g/f and spent 250 total i believe, i baught a 4 gauge schoch wiring from wal mart, baught a refurb rf he2 from ebay for 85 bucks and its still bumping good and baught a 375 watt us akustics amp from ebay for 100, and she used here stock head unit so i jsut paid like 5 buck for a line converter and a custom bock at a audio shot for 35 sealed that was 1.35 cu befor sub displacement which was about perf for the he2. total i kno she didnt pay over 300 and everything is still working fine and bumps real good, she thinks it's perfect, and its meld real nice with her front stage, she drives a focus zx3 by the way if anyone cared.
edit: i didn't see your ohm thing,if you want the cheapest thing get a dual 4 12 sub because theres a lot of choices out there for 2 ohm stable mono amps.
05 Scion tC
Subs = 15 inch power hx2 in 3.5 cu/ft at 32 hz
Sub amp = Cadance ZRS-9
Ford BNIB 240 amp alt, only 200 shipped
Refs: T9X, spoonraker