# Port tuning frequency measurement.



## coobah (Mar 24, 2009)

Hi!

Is this possible to somehow measure/check the port tuning in a BR enclosure?

I have a tone generator (laptop w soft.), M-audio Pre USB and Behringer 8000 mic. Also having some soft like WinAudioMLS or TrueRTA but didn't use those toys yet.


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## Oliver (Jun 25, 2007)

coobah said:


> Hi!
> 
> Is this possible to somehow measure/check the port tuning in a BR enclosure?
> 
> I have a tone generator (laptop w soft.), M-audio Pre USB and Behringer 8000 mic. Also having some soft like WinAudioMLS or TrueRTA but didn't use those toys yet.


The subwoofer will move less near the tuned frequency , a frequency meter and some flour on your cone [ if it is facing up ] will allow you to get pretty close.

As the sub approaches the tuned frequency , the Helmholtz resonator will be exuding the most sound. { Xmax will become minimal as port takes over reproducing sound }.

Use a cd with frequencies , *25 Hz through 55 Hz *, out to do it !!


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## coobah (Mar 24, 2009)

OK but will this kind of check be accurate enough and (mostly) safe if my port is (or should be and that's what I want to check) tuned to 25Hz???

It's a W10Gti in a 49,5 liter (1.75cft) which is built according to specs from manual.


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## The Baron Groog (Mar 15, 2010)

Yes, provided your subsonic filter is turned on or you keep the volume down


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## 94VG30DE (Nov 28, 2007)

Wouldn't a WT3 Woofer Tester be able to show this too?


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## The Baron Groog (Mar 15, 2010)

yup, it would, 80bucks in PE's sale-if still on-I got mine last month


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## Ricci (Sep 30, 2008)

Anyting that can take an impedance versus frequency measurement like a wt2 will be able to show it. The low point in the saddle. Or you can take a very close mic response sweep of the port or the woofer. The woofer will have an obvious notch in response. The port will have a peak. Even very low volume levels will work for this.


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