what does port width change?

[disturbed_cbr 10+ year member]

I had a 3 inch port on my box i recently changed it to a 4 inch i have pics on my profile thanks for any info....

Click to read more...

 

[squeak9798 5,000+ posts]

Port width changes the port area, which is going to change the tuning frequency assuming length stays the same.

Is that what you were asking ?

 

[disturbed_cbr 10+ year member]

Yes sir..... I just changed that port width to 4 inches instead of 3 and everything else is the same and also i have a 2nd port board will it make a difference in moving that too from 3 inches too 4???

 

[Big Dee 10+ year member]

Your tuning frequency is going to rise every time you raise the port area. It's up to you if you want to do that or not. If you like the sound now i wouldn't change it.

 

[disturbed_cbr 10+ year member]

THANKS! Thats what i was mainly after what happens to the tuning frequency right now im at like 35Hz and it JAMZ i do want it louder though i listen to alot of rap and rock so what do you think i should do?

 

[Phreaker 10+ year member]

I was trying to help and design someone a box for four 10" AA Assassins and decided on 84sqin of port area and we were going to use 20.25" of port length for a 32Hz tuning....I got thatlength by looking at the port length of a 5ft^3 box but didn't even remember that box tununing will rise everytime you up the port area.

What would be the proper port length for a 5ft^3 box tuned to 32Hz with a 4" x 21" port (84sqin of port area)..?

I used this port calculator http://www.carstereo.com/help/Articles.cfm?id=31

and I plugged in 4" to the port height and 21" into the port width and it gave me 18.78" for port length,then I plugged 21" into height and 4" into width and it gave me 27.28" of port length....which would be correct?

Here is the box plan...

 

[theCybe 5,000+ posts]

what do you think I should do?

Use a calculator //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Trixter 10+ year member]

Use a calculator //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

where did that quote come from?

 

[Trixter 10+ year member]

I was trying to help and design someone a box for four 10" AA Assassins and decided on 84sqin of port area and we were going to use 20.25" of port length for a 32Hz tuning....I got thatlength by looking at the port length of a 5ft^3 box but didn't even remember that box tununing will rise everytime you up the port area.
What would be the proper port length for a 5ft^3 box tuned to 32Hz with a 4" x 21" port (84sqin of port area)..?

I used this port calculator http://www.carstereo.com/help/Articles.cfm?id=31

and I plugged in 4" to the port height and 21" into the port width and it gave me 18.78" for port length,then I plugged 21" into height and 4" into width and it gave me 27.28" of port length....which would be correct?

Here is the box plan...

thread jacker....

 

[Trixter 10+ year member]

THANKS! Thats what i was mainly after what happens to the tuning frequency right now im at like 35Hz and it JAMZ i do want it louder though i listen to alot of rap and rock so what do you think i should do?

you could make it somewhat louder by adding more volume to the box. (but that depends on the size you have now and the power your putting to it. if you go too big the sub could get damaged....again, depending on the power.) if you gho the route of building a new box, then make sure to add a lot of bracing. bracing will reduce vibration and turn that lost power into sound.

 

[ultimate157 5,000+ posts]

thread jacker....

post whore //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif :laugh:

 

[Trixter 10+ year member]

post whore //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif :laugh:

SH*^...lol...gotta break it down by person, my man. look how many posts i have compared to my joining date.....not a post ***** by far...ratio wise you pass me....lol

 

[Phreaker 10+ year member]

thread jacker....

WHOOPIEEE.........Saw the thread thought I'd ask......dipshit.

 

[Big Dee 10+ year member]

I wouldn't make it any bigger. When you play notes below the TF (tuning frequency) the cone excursion goes way up. If you make the TF too high the driver will be maxing out a lot, and that's not a good thing. It's ok at 35 hz because a lot of music doesn't have much sub-35 stuff, but if you raise it to say, 45, there might be a lot of music that playes below that.

 

[Trixter 10+ year member]

I was trying to help and design someone a box for four 10" AA Assassins and decided on 84sqin of port area and we were going to use 20.25" of port length for a 32Hz tuning....I got thatlength by looking at the port length of a 5ft^3 box but didn't even remember that box tununing will rise everytime you up the port area.
What would be the proper port length for a 5ft^3 box tuned to 32Hz with a 4" x 21" port (84sqin of port area)..?

I used this port calculator http://www.carstereo.com/help/Articles.cfm?id=31

and I plugged in 4" to the port height and 21" into the port width and it gave me 18.78" for port length,then I plugged 21" into height and 4" into width and it gave me 27.28" of port length....which would be correct?

Here is the box plan...

eventhough i'm a dip$hit...i'll help ya out a little. the reason your getting the variation is because of the end correction factor. since the correction factor is 1/2 the port's width, when you put in 21" wide it is considering a 10.5" correction, when you make it 4" wide it's only doing a 2" correction. if you choose "no" for slot port, the numbers will be the same. also remember that this calculator is for a pre built box. meaning what ever the length is that it calculates, you will need to find the volume and add that to the box. if the box is built, then you will need to find the port's volume, subtracat that from the original box volume and run that number again to get a new port length.