Re: Need help with ports, crew cab 2500hd with 4 E8v3's
aero ports would be the way to go because a slot port would take up a lot of volume, and i would try to not go much below the .75 ft^3 mark per speaker. so you've go two options. the first would be to do the ports facing forward, but as you've stated your limited to 14.5" deep. 2x 4" ports would be too long, and the next size down would be 2x 3" port. to get 35Hz the 3" ports would need to be 9.25" long overall. the second option i can thnk of would be side firing ports. here the best route would probably be 1x 4" port firing out one side and another firing out the other side. this option would give you more port area, which is desirable if your running near or more than the recommended power to these subs. the question is whetehr the 2x 4" ports can fit in the box. if they can, and there is clearance on the sides of the box for the ports to fire (only a couple inches is necessary) then the ports would be 17 long, with a net displacement 2.8 ft^3, giving .7 ft^3 per sub. in this second case the tuning freq would be slightly higher at about 35.7Hz. the ports come 17" long standard, and i wouldn't recommend making it an inch longer to achieve that .7Hz decrease.
if you want to play around with the calculations yourself:
and the ports can be purcahsed from:
in your box design i would modify one thing also: add a small amount of support between the subs on either sides. when the would thins down it can get rather weak, and the being the baffle of the box, it is important that it stays sturdy.
4x 12" HDC3's
1x Hifonics Maxximus (rated 10,000@1ohm)
2x Powermaster D3100
8x runs of 0 gauge
1x stock alt
155.2 dB legal (vehicle off and @50Hz) in a Ford exploder