port question

[loudnoises]

I have always been told to measure down dead center for port length. I have seen some people measure lines down the center from one end to another, add them up, and determine their port length that way. Here is a little sketch on paint to explain better. I know alot of you have tons of experience, so what would be the correct way? fig A, or fig B? :confused: Thanks for the help!

http://i96.photobucket.com/albums/l164/dmz2711/tlmeasurement-1.jpg

[CalusaCustomConcepts]

The correct answer is B.

[loudnoises]

The correct answer is B.

awsome, thank you!

[Sonicx2c]

YES I agree with "MR. GET OVER IT!" but to be 100% correct you will need to add 1 half on the port heith to the port length.

[loudnoises]

YES I agree with "MR. GET OVER IT!" but to be 100% correct you will need to add 1 half on the port heith to the port length.

why is that, end correction? please explain, thanks!

[Sonicx2c]

This is the correct method when using any one enclosure panel as a port panel, if you have never heard this.... trust me ......it is correct! I have played so much over the years, I know many secrets......

[Sonicx2c]

Hey Buzz Light Year, I may be alittle rusty but I still GOT GAME !!!!!!!!

[CalusaCustomConcepts]

Here is a link to "MR. I GOT GAME's" correct addition.

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

It's from JL Audio's website tutorial on port calculation.

Check out the bottom of the page for the end correction info. You'll see it's not actually the port height, but the port width or distance of the inner port wall from the box outer wall.

The box you have drawn is not actually a bass reflex enclosure. It's a transmission line, and the effective port length end correction info does not apply to that design.

[Sonicx2c]

This would be a TL enclosure and the end correction factor would not apply to that design. Thanks for pointing out the box not being a vented alignment , an over sight on my behalf. However........ I see the GAME and though it would be fun.......you have already lost.......SORRY BUZZ but read JL's site one more time. AND THE BEAT GONES ON !>>>>>>>>>>>>>>>>

[CalusaCustomConcepts]

However........ I see the GAME and though it would be fun.......you have already lost.......SORRY BUZZ but read JL's site one more time. AND THE BEAT GONES ON !>>>>>>>>>>>>>>>>

Chuck, you're a dork!:rolleyes:

Yes. JL audio uses the TERM height. But that's because they are building a port BELOW the sub. If you do a traditional slot port(on the side of the sub) then you would use the width. Which is why I explained it as the distance of the port wall from the box wall. Their tutorial is not as clear as it could be.

Furthermore, I challenge ANYONE to add or subtract 1-2 inches to their port length and report the difference. You WILL NOT hear a difference. The tuning MAY change, but depending on the enclosure/port/sub it's possible that it won't.