ok, my boy has a 12" infinity kappa that he is trying to sell me, i want to know if this is a good speaker, and if it has any falts in it. also what is a good amp to go with the kappa? he is selling me the infinity w/ a box, and an u.s. acustic amp, i beleave its 520 watts(dont quote me though) for $250. all is brand new and still has a warrenty (and not stolen). im pretty sure that the price is really good, but not to sure of the quality of the products. please help me tks