subs up port back like steves hoe box i would go 38 and up on ur tuning maybe over 40 and also if ur just all out spl u need to find out what ur car frequency is then u would tune alittle higher than that but just wait for some of the spls guys to get on and they can tell u what u should really tune to because i dont really go alot towards spl maybe if u can catch steve ask him