when calculating port length

[absami]

when we calculate circular port length for our desired frequency on different sites does that include the thickness of the enclosure which is 0.75?

following are some sites to calculate vent length

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

http://www.carstereo.com/help/Articles.cfm?id=31

http://www.psp-inc.com/psp-inc.com/cgi-bin/port_length_calculator.cgi

Click to read more...

 

[Fique 10+ year member]

Very good question. If the thickness was 3/4 your vent is now that much shorter. I would guess they are soley looking at internal specs. as if your thickness was zero". Port should be said dimension INSIDE of box.

I may be wrong.... It could be inside dimension of vent which would include wall thickness....

 

[skmfkr 5,000+ posts]

you enter your net volume

 

[FOSGATE JOE 10+ year member]

yup

 

[Fique 10+ year member]

I think you guys are missing his question. When it tells you how long to make the port, does that include the enclosure wall thickness that the port is in.

 

[jshak07 10+ year member]

If your using aeroports that means from the end of each flare.

 

[absami]

aeropots r not available here so ill b using pvc pipes....so if i get a port length of 8 inch for tuning 33 hertz i would add 8 inch + 0.75 wall thickness = 8.75 or 0.75 wal thickness + 7.25 = 8 inches.....get my point?

 

[SomeGuyDude 10+ year member]

Well that kinda depends on how long you want the port to be. If you want an 8" port you would probably want to cut an 8" pipe and then have it put into the wood so the plastic is flush with the FRONT surface. You have to think of the port length as "space for the air to move through". If you take an 8" pipe and then just stick it on the back side of a block of wood two inches thick, you just added two more inches for the air to go through, so your "port" is now 10" long.

 

[absami]

so the wall thickness acts as a part of port...thats what i wanted to know....

 

[phemps 10+ year member]

so the wall thickness acts as a part of port...thats what i wanted to know....

No.. Because you inlay the PVC into the wood there is no area that the wood should be uncovered in the port before the PVC starts? How in the hell would you secure the port otherwise?

 

[pawn man 10+ year member]

most ppl cut the whole big enough for the pvp to slide in so that the front of the box is flush w/ the pvc.