So.. I had one Alpine type R 15 (4 ohm dvc) in 4cuft box(32hz tune) on Hifonics brutus bxi6000d (2kw on 2ohm) with 0 gauge wire, 75a alt, 2x 55ah batteries and it was working like a charm.. subwoofer was moving 15-20mm in one way no smell and he was cool.. and now I put another Type R 15 so two...