I have a old kicker SX 1250.1 amp. its rated 1250+ at 1 ohmn. my question is what would be better for the sub and amp? 1 or 2 ohmn's? the 1 would be getting more watts so it would be louder but if i ever switch amps will that effect the 1 ohmn? the sub would be a 12in Fi BTl N1 sub, its rated at 2000rms, idk which to get 1 or 2?