I think i'm going to purchase the 12" Shiva and put it into a 1.25 cubic foot sealed box. This is going into a Jeep Grand Cherokee. Is the JLAudio 500/1 overkill for this sub? Cause with the sub has dual 8ohm and i hook it up in parallel that will give me 500 rms @ 4 ohms with that amp. Also how does this amp have the same output whether its at 1.5 ohms - 4 ohms? I can get this amp for $400, which is the most i really wanted to spend on an amp. Is there anything that'll do a similiar job that costs less? Thanks.