aeroport length tuning?

[ShiningBuick 10+ year member]

Ok, so I have searched and searched, and I simply cannot figure out how to determine the Hz a box will be tuned at.

Lets say I have a 3 cu. ft. box.. I want to tune it to around 32 Hz (seems a common tuning). I have 1.5" tube to do this.

If there an equation I can plug this stuff in to determine how long to cut the tube to?

If someone could explain it that'd be tops, I couldn't find anything I understood in stickies/search/google.

Click to read more...

 

[dB-SPL 10+ year member]

1.5" is a bit.. Oh.. Tiny. You would need two of them about 2" long to get around 32Hz, But I wouldn't suggest it. You should get larger diameter tubes. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

-Bill-

 

[BrianChia 10+ year member]

Yes. There is an equation. This is a good read:

http://mobile.jlaudio.com/support_pages.php?page_id=165

 

[yunvme666 10+ year member]

what kind of subs are you using? i have some aeros fs.....

 

[ShiningBuick 10+ year member]

Two POS kicker free air 10"s. I got them for free and tossed together a sealed 3 cu ft box and I'm pretty sure it's too big, since the response I get with it is sloppy and I can't hit higher-bass notes worth a crap (for example, certain parts of King King in the Trunk - Jibbs and so forth).

I figured I had some PVC pipes laying around and I'd just cut a hole (or two) and stick the appropriate length on PVC in and see what I come up with. If I dick up the box.. who cares, I'm still learning all this and whatnot, so why not experiment with some crappy subs before I get a decent system where I have to build a box for it.

Thanks for the link, too, Brian. Hopefully I can finally learn how this big mystery works, lol.

 

[dB-SPL 10+ year member]

With 1.5" PVC, your port area will **** near suffocate..

-Bill-

 

[DBfan187 5,000+ posts]

http://www.psp-inc.com/psp-inc.com/public_html/..%5Ccgi-bin%5Cport_length_calculator.cgi

?

 

[ShiningBuick 10+ year member]

Duely noted.. I found some 3" PVC in my basement. Perhaps I shall try that instead.

So I plug-n-chugged my way through the first calculation.. before I checked back and found someone posted a calculator. Lol.

The good news is I got the same number both ways.

So.. If I put in one 3" port, to tune it to 32 Hz, I'd make the port 4" long. And If I tossed two 3" ports in, Just for funsies, they'd have to each be 10.21" long, am I to assume? Or would I cut that 10.21" in half to get 5.1" long each?

According to the JL audio read, when using multiple ports, the ports'll be longer per port than if one was using a single port. It seems to me the 5.1" would fit with their example the best, but I'd just like to check and make sure.

Thanks for all the help so far guys!

 

[dB-SPL 10+ year member]

Correct. If you were to use two 3" ports, each port would need to be 10.2" in length to tune a 3-cube box to 32Hz.

-Bill-

 

[ShiningBuick 10+ year member]

Ok... next question, Are there any positive aspects of having 2 ports instead of 1? Or vice verse?

I'd assume not, but I'd like to make sure.

 

[PSturmer 10+ year member]

http://www.psp-inc.com has a calculator to do it.

 

[ShiningBuick 10+ year member]

Well guys... just got finished. Chopped a 4" piece of PVC, cut a hole for it, pounded it into the hole, and tossed them back into my trunk.

What a difference! The range it covers now actually is what it's supposed to cover! I hit all the notes on the various rap songs I tested on it, and it's a good bit louder than before, too.

Actually I'm amazed by how loud it is, considering I'm running these wired in place of the 6x9's off the factory amp, Amazing what like... 100 watts or so will do. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Thanks for all the help, worked out so well.