im gona go for a 15inch in a ported box, but im not too sure what size to make the box, i currently have a directed 1500d but it doesent seem to work properly firstly none of the controls work, i have the gain set to full and it doesent do anything to my kicker l7, also that amp stops giving power to the sub at low volumes and i gotto turn it real high from the HU to get the bass back:uhoh: so it must be messed up so i wanna get a new amp to go with a new sub im gona get