Ok. I need to know how long to make my ports. The calculator on the site is only for 1 port. I want 2 for the lower port velocity. I went to www.caraudio.com or www.carstereo.com and they have a calculator for 2 ports. That site said to make them 14.51 for each. I emailed Audiobahn and they finally wrote me back and said to make them both 22 inches. Here's the details. The box has 3 chambers for 3 12's, Audiobahn AW1208T's. There is 2.69 cubic feet in each chamber. There are 2 ports in each chamber on the top at the back. The speakers are mounted backwards on the front of the box so they don't take up any air space. I want each chamber tuned to 38Hz. The port diameter is 4 inches. If any can tell me which number is right I'd really appreciate it. I hope it's the 14.51 because I cut and mounted the ports today before I got the Audiobahn email. Peace
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$4000 stereo in a $1000 whip, thats how u do it
For two ports you take the length and diameter that would be required when using one port, and you dived it by two, or three, or four, for how many ports you're going to be using. As lon as the combined volume of all the ports equals the volume of the single port you'll be good
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Poormanq45 wrote:
For two ports you take the length and diameter that would be required when using one port, and you dived it by two, or three, or four, for how many ports you're going to be using. As lon as the combined volume of all the ports equals the volume of the single port you'll be good
That is wrong. Port math does not work like that. You cannot simply cut the length in half as it will not function the same as one longer port. For example, to tune a 3 cuft enclosure to 30Hz, a single 3" diameter port neds to be 4.86" long. Using two 3" diameter ports, each needs to be 11.92" long. Here's a good calculator.
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Support the12volt.comThats the calculator I used to get 14.51. But Audiobahn said they should both be 22. I already made them to 14.51 and have them set in the holes in the top of my box. I was trying to get another opinion before i glued and screwed the lid on my box and covered it. If anyone knows anywhere else that has a calculator please tell me. Thanks for the help though. Peace
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$4000 stereo in a $1000 whip, thats how u do it