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New member Username: ZippittaMulberry, Florida United State... Post Number: 2 Registered: Apr-04 | I have always used nothing but enclosed boxes because I ave been too timid to experiment with vented. I hear that a vented box can increase spl by 3db and I would like to know how to match port sizes with the box and sub's so I dont have to worry about ruining my shizzle(dont make enough dough to be doing trial and error...lol) How do you decide what the correct port size is? I have 2 Audiobahn AW1200Q Thank You |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 2146 Registered: Dec-03 | 12" subs 4" inner diameter ports you want the box to be 2cu ft per sub after subtracting the speakers' displacement, and the displacement volume of the port tubes (volume of a cylinder, simple geometry) then you want one port per sub each port should then measure: 11.4" long 4" inner diameter your port area will be 12.566 inches^2 your port volume will be 0.083 ft^3 Port tuned freq will be 35Hz there. all done. make sure your box is 2ft^3 *after* adding teh subs and ports.. not before. otherwise you end up with a box about 1.5ft^3 and the ports will be totally wrong you'll have to get teh driver displacement yourself from Audiobahn's spec sheets |
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Bronze Member Username: SouthernrebelLouisiana USA Post Number: 44 Registered: Mar-04 | i dont recommend using a port any smaller in diameter than 3"...the diameter of the port, sud displacement, tunning frequency, and box size all play a role in a port length. if you wanna build one use this calculator to do so: http://www.eatel.net/~amptech/elecdisc/spboxnew2.htm |
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Bronze Member Username: HiphopanonymousPost Number: 37 Registered: Dec-03 | hey glasswolf? can you calculate port measurements for me. i've tried bcae and i dunno how to work it. i have two alpine type r 12 DVC 4 ohms. i want them slot ported, so plz gimme dimensions for the rectangle ports. and i been hearing you say that 35hz is the most optimal, so that'll be nice. i don't have much room in my coupe so make the volume as small as you can if you can. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 2157 Registered: Dec-03 | if I start doing this, I'll have everyone asking me to design boxes and measure out ports for them. I'm trying to avoid that. |
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New member Username: ZippittaMulberry, Florida United State... Post Number: 3 Registered: Apr-04 | Thank You... I really appreciate the help. |
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Bronze Member Username: SouthernrebelLouisiana USA Post Number: 49 Registered: Mar-04 | hiphop....just use the calculator on the link i posted...its really easy |