port length question, is this accurate?

[01 S 10 10+ year member]

Im using a formula to calculate the port length with my TI-83 calc, and also using carstereo.com port length calc online (which i have been told to be very accurate). This is a slot port.

12cf net

port 6" x 30" (180sq inches) tuned to 36hz, its giving me only 5.12" long... that seems very short, i was thinking it would be around 18" long.

can someone verify the length? or give me the correct length?

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[Rashaddd 5,000+ posts]

17.4 inches

 

[skmfkr 5,000+ posts]

that car stereo port calc will change if u switch the port width and height...so i dunno how accurate it is

 

[01 S 10 10+ year member]

that car stereo port calc will change if u switch the port width and height...so i dunno how accurate it is

yeah, i heard it was pretty much dead on if your port "width" measurement is the side of the port that shares the box wall, 30" in my case. (but i might have this backwards, and that would make sense because that would give me ~17.1", if i use 6" as my width instead of 30, and 30" as height)

 

[01 S 10 10+ year member]

anybody else want to chime in? does ~17.5 inches sound correct for 12cf net, 36hz, 6" x 30" (180 sq. in. ) port?

 

[01 S 10 10+ year member]

bumpy, 17.5" right? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[Rashaddd 5,000+ posts]

It's right.

 

[01 S 10 10+ year member]

It's right.

have you used the carstereo calc before? some think it is real close, its giving me about 17.12" so i guess its pretty accurate if you use the port wall sharing the box wall (biggest number, in my case 30") as your "height". either way, thanks a lot for the help, My TI-83 calc is fckin up, so i got some $8 cheapy that im tryin to work with, so id rather use carstereo.com calc LOL

 

[Rashaddd 5,000+ posts]

have you used the carstereo calc before? some think it is real close, its giving me about 17.12" so i guess its pretty accurate if you use the port wall sharing the box wall (biggest number, in my case 30") as your "height". either way, thanks a lot for the help, My TI-83 calc is fckin up, so i got some $8 cheapy that im tryin to work with, so id rather use carstereo.com calc LOL

If you're off by like an inch even you'll likely never know...and yes I tried there too and got like 17.1