need help with port

I'm not sure what an end correction is. Do you come up with a port length of about 13-1/2-inches

 

could the be the thickness of mdf being used?

 

I'm still not sure what the end correction is, because if we take into account port and speaker displacement, then the port will be longer. Not shorter.

In BassBox are you inputting external or internal dimension? mrmizcue might have something.

 

end correction is when you are running the port along side an outer wall.

Take half of the port width and add it to the total port length and that is your real "port length"

so if you have a slot port that is 5 inchs wide and 30 inches long...the actual port length is 32.5 inches long...its weird but this is the simplist way I can describe it lol

you are using a round port so end correction doesn't really matter.

I'd use atleast two 6 inch round ports...the 19Ov.2 can move some air

 

I love it I learned something. So this only applies to ports that are using one of the boxwalls as part of the port?

 

yes..only slot ports that use a box wall as a port wall...as far as I know

 

azn, what's going on with you man, your brains like a sponge LOL.

End Correction WinIsd

The effective length of the port is found by adding an end correction factor. An end correction factor is necesary because more often than not, one wall of the port is also one wall of the enclosure and this wall extends beyond the end of the port thus effectively adding length to the port (remember, the driver can't "see" the length of the port, it can only go by what it "feels" is going on).

Calculating end factor may sound like it would be more trouble than it's worth, but it's actually quite simple. To calculate end correction factor, simply add one-half of h to the physical length you calculated above (L1 + L2).

 

with that being said.....he is telling bb that he wants a 6" port....and it is still telling him that there is a end correction....wouldn't the prog just add end correction for a slotted port...and not for a 6" round?

 

This is what bassbox pro is saying...

Vent Cross Section Shape The cross-section shape of the vent affects the end-correction factor and it changes the cross-section dimensions. Three choices are provide: round, rectangle and other. The “other” selection is provided for cross-section shapes that are not round or rectangular. It can only estimate the end correction and the closer the shape is to round, the more accurate it will be.

What is “end correction?” It’s an internal parameter that compensates for the fact that a vent usually appears to be slightly longer than it really is. This is because the air immediately outside each end of the vent will vibrate along with the air inside the vent. This is illustrated below:

Copyright 1992-2004 by Harris Technologies, Inc.


The end correction of a round vent is equal to the internal diameter (Dv) of the vent. For example, a vent with an inside diameter of 2 inches will appear to be 2 inches longer than its actual length (Lv).

The end correction is affected by both the cross-section shape and the end type. BassBox Pro automatically estimates the end correction and uses it for its internal calculations.

Vent End Type The “end type” refers to the way the vent terminates on each end and it affects the end correction described above. Five choices are provided: one flush end, two flush ends, no flush ends, one flared end and two flared ends.

Copyright 1992-2004 by Harris Technologies, Inc.

 

sorry electro.....you had posted while was typing....thanks for the info....did not mean to step on your toes

 

huh? lol don't worry about it. Yes end correction is for round, square, triangle whatever shape port you use. I just let the program do it. We all get to learn something today wohoooo..

 

yayy im excited lol shiatt

 

Gotta celebrate now

 

dude...i dunno...haha...damn

 

It would work...but there really is no need for it.

An ABC box reduces excursion buy adding another port resonance...because near port tuning the excursion is greatly reduced...so then you have two points of reduced excursion.

The 19Ov.2 has PLENTY of excursion...i've played some songs with the 19Ov.2 free air giving it 800-100 watts and it didn't even get near bottoming out