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Pi one port [message #73117]

Sun, 24 June 2012 09:01

48h350
Messages: 11
Registered: November 2011
Location: AUSTRALIA

Chancellor

Hi Wayne , I am assembling a pair of Pi one.
I have obtained a port duct from PE : http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-478
Unfortunately it is flared and has the required diameter nearly in the middle, it is much larger at the end that will be on the face of the baffle.
I can cut the duct to the required length, no problem there.
What worries me is the diameter of the port: does it have to be of the designated size all the way , or just at one end is enough?
Thanks.

Massimo

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Re: Pi one port [message #73120 is a reply to message #73117]

Sun, 24 June 2012 19:40

Wayne Parham
Messages: 18786
Registered: January 2001

Illuminati (33rd Degree)

Well, it was designed for a port that has uniform cross-section. Flared ports are good for reducing turbulence at high airspeed, but then again, the port on this model is so oversized it'll never even get close. Still, I think you'll probably be OK. Maybe just add 1/4" extra length to make up for the flare. You can always check the Helmholtz frequency when you're done, and if it's between 57Hz and 63Hz, it's fine.

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Re: Pi one port [message #73128 is a reply to message #73120]

Mon, 25 June 2012 09:13

48h350
Messages: 11
Registered: November 2011
Location: AUSTRALIA

Chancellor

Thanks Wayne, i will add the extra 1/4 inch.
Can you shine some light on the method of checking the Helmholtz frequency when the cabinet is finished?
Thanks for answering on a Sunday.

massimo

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