Square mdf port.

[Mitch86]

I need a little help. I've decided I'm just going to build a square port instead of wasting more money on this box. Box will be 2.9-3 cubes... I need to know the deminsions of a sqaure port that would give me 38hz and no port noise. I ran this through an online calculator and got a 4x4" port 7"long. Would that get me what I need?

[acold7dusta]

4 inch PVC make it a lil longer FTW?

[j3bus2k3]

Need more port area. 14-16in^2 per cubic foot is a good rule of thumb....

[mazdakid]

4 inch PVC make it a lil longer FTW?

id rather use a square port ftw

[acold7dusta]

ok make more work on yourself, and take up more volume, be my guest

[xluben]

4 inch PVC make it a lil longer FTW?

a round port would have less port area and therefore have a greater chance of port noise and would have to be shorter to achieve the same tuning.

for a single 12" sub you should probably have about 25in^2 of port area.

also, is that 3ft^3 before port displacement?

[kicker06]

I had a 6x4" port for my L7 and it had no port noise. Rounded the edges though.

[mbrooky]

try using this calculator:

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

you could go with a 5x5 port, 11.5" long