This is not my first system but I am still on a budget. Pretty small budget of around 350 to 450 dollars for a box amp and sub. I want more of an SPL system. My past systems have been 2 12 inch Boston G1's, 1 15 MTX Road thunder, 1 15 inch Boston G2. I am looking for either probably a single 15 or a pair of 12's. I also don't want to have to upgrade my electrical system. So I'm looking for loud, cheap, but not to much power. I have my eyes maybe on a pair 12 inch Pioneers TS-W310D4's Pioneer TS-W310D4 (tsw310d4) 12" Dual 4-Ohm Champion Series Car Subwoofer . I am looking for any and all your input! I recently have been looking into SoundQubed there HDS200's. Any knowledge on these? If I want to run 2 12's is that to much power to run off my stock 03 monte carlo? Also when looking for subs, what do I look for exactly when trying to decide which ones will be louder. Sensitivity? Rms Power? Both? Thank you for all your future input!