ported box

after a failed first at building a box on my own im looking for some help i have a sundown e8v2 that im trying to have a down fired ported box for. it will be installed in a 05 silverado extended cab i came up with these for demensions. 20in wide, 12in deep, 8in tall if i go over the drivetrain hump i can have a little more room. this was the first box that i built and it sounded horrible,

i would like it to be 0.60 ft^3 tuned to 35 Hz if possible.

bump

The box you built is barely .5 cubic feet and that gets even smaller once the sub goes in. That box should end up tuned to 32hz the way you have it . Its tuned too low for a reqular 8 inch sub. The box is most efficient at making notes that the sub can barely produce without distortion. Im not familiar with that sub but that would be my diagnosis.

if id build a box the same size and use a pvc port instead would it work? or do i need to come up with more room somehow first. thats really my max demensions unless i drop the bottom down 1/4in

this might sound strange but you can just cut inches off of the port until you get to something that sounds right, BUT you will need to use a sub sonic filter to filter the frequencies below about 38hz. if you have a half decent bass amp then it should have a sub sonic filter built in. the filter will protect the sub from having to play frequencies below what the box will be tuned to. by cutting the port inch by inch you are basically raising the tune of the port little by little and should make the sub more efficient for higher frequencies that it is more suited to playing. i wouldn't cut more than about 8 or 9 inches off of the port and if it still doesnt sound better then i would build a box with more overall airspace. remember, box volume and port volume are two separate things so you cant include the space the port takes up in your overall box volume. it must be kept separate to get an accurate tuning and you have to take into account how much air space the sub takes up too, it shouldnt be much but it could be enough to throw your specs all out of whack.