Are these 12 inch subs good?

Depends what kind of car and also what type of "bump" your looking for. If your in a truck like a silvarado or a ford explorer then two 12s under the seat would be nice but if you have a car like an impala I might even move to a bigger sub and put them in your trunk. Hope that helps, I drive a 2010 chevy silvarado with two 12s under the back seat and its amazing.