well just cuz its a named brand dont mean its good.... with the right tools and calculations u can build a box that will blow that one out the water..... second, where do u go off saying 1 15 is better than 2 12s, thats just retarded..... thats like saying 1 10 is better than 2 12's...... its all in the install. And third y did u buy such a small amp to power two 12's, haven't u read about R's n how they take more than just 400 watts, thats like an appetizer when they need a friggin steak...... r u sure ur system is nutz with that little power? n btw dont anticipate better sound from 1 sub with the same amount of power u're giving 2.... will be hardly any differnt...... u just need a new amp... sorry dont mean to be a dick