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View Full Version : Port tube and its purpose

MarineGYSGT
08-06-2005, 06:31 PM
I have been into car audio for almost 15 years, you know just listening and getting the loud spl but not really ever studying it. What exactly does the length and size of a port do. I had the guys at TeamToxicBass design me a box and he told me to use 2 3"X15" ports. I am going to do it because he said to but what is the real reason I am doing this? Can anybody really give me a good reason why?

Bake
08-06-2005, 11:39 PM
Port size and length are determined using a mathmatical computation of your sub's measured parameters and the wave length of the desired tuning frequency.

Tehgregzor
08-06-2005, 11:45 PM
my freind seth has an re in a port. and mark also ahas one that i selt h im for 80 dollars. and it gets really loud when we put it owrads the bak of the truck. i like it. we are going to put l barcaes on it soon. ii thin oonce he gets his headunit on then it woill sould beddtter than its does now because the bas sloppy and its frimo a stupid mp4 vcd player and it ejects when he leas t expect s it. i've seen it and uit *****.

mobileaudio219
08-07-2005, 01:46 AM
my freind seth has an re in a port. and mark also ahas one that i selt h im for 80 dollars. and it gets really loud when we put it owrads the bak of the truck. i like it. we are going to put l barcaes on it soon. ii thin oonce he gets his headunit on then it woill sould beddtter than its does now because the bas sloppy and its frimo a stupid mp4 vcd player and it ejects when he leas t expect s it. i've seen it and uit *****.

holy crap, you just blow my effin mind... launch? :crazy:

I want SExxx
08-07-2005, 03:14 AM
Port size and length are determined using a mathmatical computation of your sub's measured parameters and the wave length of the desired tuning frequency.
It has nothing to do with the sub. The port is determined by the box and the longer the port of the same area in the same size enclosure will result in a lower tuning, as will a bigger box with the same port area.

flakko
08-07-2005, 06:06 AM
It has nothing to do with the sub. The port is determined by the box and the longer the port of the same area in the same size enclosure will result in a lower tuning, as will a bigger box with the same port area.

a little bit no? displacement.

MarineGYSGT
08-07-2005, 09:36 AM
Hey Guys thanks for th help. I at least get the basics now. But thegregzor just confused the hell out of me like he did everybody else. LOL. That has to be a joke

Bake
08-07-2005, 11:37 AM
It has nothing to do with the sub. The port is determined by the box and the longer the port of the same area in the same size enclosure will result in a lower tuning, as will a bigger box with the same port area.

So any 10 or 12 inch sub will be completly interchangable in any ported enclosure built for a sub of the same size reguardless of T/S measurements??

snebes
08-07-2005, 12:15 PM
So any 10 or 12 inch sub will be completly interchangable in any ported enclosure built for a sub of the same size reguardless of T/S measurements??

No. The port is not DIRECTLY related to the sub, but it is to the box. The box size is still determined by the T/S parameters of the sub. If you had a few subs that want similar airspace, though, that should work...

Bake
08-07-2005, 01:05 PM
Cool, thanks, the only ported enclosures I have built were designed by the manufature so I guess I just assumed that the sub parameters would be figured in.

PhatTonyDeMarco
08-07-2005, 01:12 PM
my freind seth has an re in a port. and mark also ahas one that i selt h im for 80 dollars. and it gets really loud when we put it owrads the bak of the truck. i like it. we are going to put l barcaes on it soon. ii thin oonce he gets his headunit on then it woill sould beddtter than its does now because the bas sloppy and its frimo a stupid mp4 vcd player and it ejects when he leas t expect s it. i've seen it and uit *****.

You can not spell for **** man. You didnt even spell your user name correctly, dont even try to play it off as a joke :p:

I want SExxx
08-08-2005, 02:20 PM
Cool, thanks, the only ported enclosures I have built were designed by the manufature so I guess I just assumed that the sub parameters would be figured in.

Yea they have programs like WinISD where you can mess around with different tunings and box sizes for different subs, but don't pay any attention to the graphs, because that is the response in open space without taking into account any room or cabin gain, which will TREMENDOUSLY change the way a certain box will sound. Also When you were asking if boxes would work for any sub of the same size the answer is a lot of the time yes, but not always. Especially if its just a normal daily driver box like 1.5-2 cubes net to 32hz for a 12, or 4 cubes net to 32hz for a 15.