Power needed to move the cone to xmax in a particular alignment is RMS power rating. The following is an example. Subwoofer A uses a 8 layer 80mm long coil that weighs 400 grams (total MMs). This sub takes 6,500 watts to hit 35mm in a 5 cubic foot box tuned to 32 hertz. Subwoofer B has the same T/S parameters but uses a 4 layer 80mm long coil that weighs 200 grams (total Mms). Due to the lighter weight this sub only needs 3,200 watts to hit xmax in a 5 cubic foot box tuned to 32 hertz. Couple this with the fact inductance will double with subwoofer A than sub B above 35-40 hertz. Sub B is not only as loud as sub A with 3,000 less watts it will be 2-4 DB louder above 40 hertz due to inductance. This means Sub A would actually need 12,000 watts to be as loud as Sub B on 3,200.