how to tune port on a fiberglass box??

[snfsh79077 10+ year member]

im currently designing a fiberglass box for my truck and want to make it ported but done know how to tune it since ill have the subs angled and what not. it'll be a 55x13x13 box dual chamber with the whole top fiberglassed with the subs on the outer sides rising up and tilted in. ill try to sketch up and pic and put it on here.

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[Chevyaudio 5,000+ posts]

Same way you figure out the tuning with any other box. Figure up the Net airspace (after your sub/port displacement) and then find an appropriate vent length, with the propper ammount of port area.

 

[snfsh79077 10+ year member]

well how do i figure out the volume of the fiberglassed area? thats the main thing i need to know.

 

[davidfre21 5,000+ posts]

packing peanuts work alright... u just need to fill the space in and then convert whatever u used into cubic ft

 

[young_gun 10+ year member]

Yea, like davidfre21 said. Take packing peanuts and fill the box, then transfer them into cardboard boxes and measure how many you have. (WxDxH) and get the cubic feet

 

[nVRuckus 5,000+ posts]

If your trying to figure it out before building it then just look at what the box would be sqared off and minus the parts your not using on it. if your building then measuring packign peanuts are a good way to get area.