My kicker manual says to make a 2.25 cuft enclosure with a 3" wide by 12.5" high by 20.5" long vent doesnt that mean it will be tuned to about 42 hz? Im still not sure the difference of spl and sq loud and clean but still dont know the difference but if i listen to alot of rap with that like long bass notes like on the songs of late nite tip, throw it up, and what you know about that what should i tune my box to? As high as possible or as low as possible? I like that bass that sounds good and loud in the car but also if i roll down my windows it will sound good outside too so what should i tune my box to???? Thanx guys.