how far away from the enclosure wall should my port be?

[slicemaster101]

yo,
i have made sevral posts in the past few weeks and all have revieled very useful information......

well here is my question for the day......

i am constructing my first subwoofer.....
it is a vented enclosure.....the vent being 3inches in diamater......
the port has to be farly long to tune the box to 25hz........
how much room should i have between the end of the port and the enclosure wall?

should i use a elbo?



thanks,
slice😎

 

[Keld]

quote from diysubwoofer.org:
"Where should I put the ports?
Ports should be placed at least one diameter away from any adjacent walls. If this is not possible to do this, the tuning frequency for a given port length will be lower than that predicted by the equations, and this may adversely affect the results."

Keld