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quick question...


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Measure Frequency of Mechanical System Resonance - Fms

Traditionally, Fms was found using a voltmeter or oscilloscope and watching for a voltage peak. The problem with this solution is

that the peak might be wide and the voltage vacillating, as the speaker transforms acoustic energy into voltage. Another problem

with the original method is that the effects of Rem/Xem (or Le for the older generation model) were not considered skewing the

results. The Woofer Tester overcomes these limitations by searching for the first zero phase-crossing to find Fms. This technique

has several advantages:

* The rate of phase change with frequency is greater than the rate of voltage change. The test is therefore more sensitive to

changes in Fms and less sensitivity to noise.

* Unlike other tools that interpret phase from impedance, the Woofer Tester actually measures phase

* If the point of interest is passed during a frequency scan, the tester software will reverse direction and scan in the opposite

direction with half of the original step ratio. This back and forth search continues until the terminal ratio is hit. The default

terminal ratio is set to 0.1% but can be set to higher (or lower) precision.

* The effects of Rem and Xem are taken into account during this test. The result is a 'bare' circuit model for the TS parameters.

This leads to a higher degree of acuracy when it comes to extracting the remaining electrical and mechanical parameters

* Rem/Xem effects are also simultaneously modeled using the Woofer Tester Simulator core. This feedback ensures that the

final simulation is also more acurate.

* Narrow-band, real-time digital lock-on filters are used to further reduce noise. These filters have complex (real and imaginary

outputs) and are reconstructed for each frequency point to ensure that they are exactly centered on the frequency of interest.

Pasted from a random site.. Looks like the same thing..

Edited by loudNlow87

'11 Jeep Patriot New Build

Head Unit: Pioneer AVH-P3200DVD

Front: Massive CK69 Components

Front Amp: Massive NX2

Rears: Infinity Kappa's

Subs: 8 Sundown SA-8 v2's

Sub Amp: AB 450.1

XS D3100

Come on 150!

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