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View Full Version : Subwoofer box. Circle vs rectangle port


bu5ch1337
09-26-2008, 03:53 AM
Hey guys

I'm building my box and i have 2 kenwoods W3011 with a Kenwood 9104D amp.. And i was wondering what is the difference between the 2 kinds of ports (circle,rectangle). And with the circle port what piping can i use?

If anyone can help that will be great.

Thanks

malmeid2
09-26-2008, 05:31 AM
"Port wave velocity will be approximately equal to port area, for most shapes of port. Port noise from turbulence depends on the surface area to perimeter value of the port, so other things being equal, a rectangular port will generate less noise than a circular port. It will also have somewhat more losses than a circular port, i.e. be less efficient. Slotted ports tend to be inefficient but clean. The extreme form of slot loading is a distributed port, lots of very thin slots. These add a lot of damping to the speaker, and can sound great with a high Qts woofer. As for port noise, most port noise comes from the port end that interfaces with the air. It's easy to taper a circular port outwards so that it forms a smooth interface with the air, but not so easy with a rectangular port."

As for port material for a circular port, most people go with PVC because it's cheap, durable and easy to use.

bu5ch1337
09-29-2008, 11:16 PM
can anyone else help?

What is better?
8\

malmeid2
09-30-2008, 01:41 AM
can anyone else help?

What is better?
8\

Did you not read what I posted? Rectangular ports can sound cleaner if built correctly but are less efficient. Circular ports are more efficient, so they can be smaller, but at the same time you may experience some extra, unwanted port noise. What exactly can't you understand? :confused:

sruggles1976
09-30-2008, 02:17 AM
can anyone else help?

What is better?
8\

Personal opinion = I like slots!! :D

only126db
09-30-2008, 03:43 AM
Personal opinion = I like slots!! :D

I like sluts too

GiveMeBassPlox
09-30-2008, 03:44 AM
I like sluts too

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