Porting question, should be a simple answer

[rrwalkertr]

Ok, if i look at the specs for the c38 and take the surface area of the port they call out, does it hurt to split the port into multiple ports. example, if the port is suppose to be 6" diameter, would it hurt to make two 3" diameter ports spread out one on one side and one on the other side of the face of the box, thanks ahead of time.

[rrwalkertr]

for the record, i know that 2 3" diamters dont equal the same surface area as one 6", and i did look through the forums with no luck finding the answer to this question, thanks

[4313B]

http://www.lansingheritage.org/html/jbl/plans/1970s-kit.htm

http://www.lansingheritage.org/images/jbl/plans/1975-kit-plans/page09.jpg

Right of page in notes section.

[Mr. Widget]

Ok, if i look at the specs for the c38 and take the surface area of the port they call out, does it hurt to split the port into multiple ports. example, if the port is suppose to be 6" diameter, would it hurt to make two 3" diameter ports spread out one on one side and one on the other side of the face of the box, thanks ahead of time.There are some issues with dividing a large port into smaller ones.

First, you need to maintain the area. For a circle A=piR^2

One 6" port has an area of 28.27"
Two 3" ports have a total area of 14.14"... so you would actually need (4) 3" ports to equal one 6" port.


Next, as you reduce the port diameter you will increase the likelihood of port noise.

The bottom line is that within reason you can use multiple smaller ports but you need to be aware of the possible consequences and maintain the same overall tuning. In many cases you can reduce the diameter of the port as well as the length.

Widget

[rrwalkertr]

http://audioheritage.org/vbulletin/showthread.php?p=165488#post165488

I have started a post in the DIY forum, i would love for you guys to go there and start making some suggestions and comments. Thanks again for the help with this, i hope i can do a ton of these jobs in the future, im learning everyday about speakers and box design so just be patient with me, im a quick learner. thanks again.