Round Port Tuning Question.

[Demi 10+ year member]

I was going to try a round port this time. I was using the calculator off of the 12 volt site.

http://www.the12volt.com/caraudio/boxcalcs.asp

For a 2.5 cubes box tuned to about 32hz it calls for a 4 in dia tube 10 inches long. That seems like such a small port for one 12" type-x. Should i use more than one tube or what? If i do use more than one tube, then how do i figure out the tuning?

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[Big Dee 10+ year member]

I would use 2 4" ports, that would give you very low port velocity. They would have to be 23" long, each.

 

[Demi 10+ year member]

Whats the advantage of a lower port velocity? And thats a bit longer than what i can buy with flared ends. What if i used three? How are you coming up with your length? Sorry for the question flood there.

 

[Big Dee 10+ year member]

Whats the advantage of a lower port velocity? And thats a bit longer than what i can buy with flared ends. What if i used three? How are you coming up with your length? Sorry for the question flood there.

Lower port air velocity = less port noise, or no port noise.

3 ports would be even longer, if you can't fit 2 there's no way you'll be able to fit 3.

I use WinISD for calculating port length.

If you can't fit 2 4" ports you could go with a single 5". That would need a 16.6" length.

 

[Demi 10+ year member]

Lower port air velocity = less port noise, or no port noise.
3 ports would be even longer, if you can't fit 2 there's no way you'll be able to fit 3.

I use WinISD for calculating port length.

If you can't fit 2 4" ports you could go with a single 5". That would need a 16.6" length.

cool thanks alot.