Millertime1028
10+ year member
CarAudio.com Veteran
When using round ports you are able to get away with half of the ports overall diameter as the distance between the port opening and the vehicle itself. In some cases as like in mine, I gain roughly 1+ db by preloading the ports against the back hatch. Right now the ports are exactly 5.5 inches off the rear hatch and im running 10 inch ports. Done testing and so on and this specific placement of the box is the loudest. What im saying is you really have to experiment with box placement and so on. If you have an 8 inch round port, 4 inches of room will suffice, maybe even 3in. If you can design the box in way to gain a tad bit more room for the port clearance it would be nice to have that extra room to mess around with the box placement to see what works best in your truck. If you use pvc, and have to use elbows, to measure the elbow you will basically measure from the dead center of the openings of the elbow to the center of the 90 degree bend then do this from the other opening of the elbow and there ya go. Add the two measurments together and thats the usable length of the elbow. This has got pretty accurate results as far as achieving the correct tuning for box's when using elbows. Sonotubes ftw
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