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16th October 2009, 01:43 PM  #501  
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16th October 2009, 01:46 PM  #502 
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I sum the "magnitudes", and yes, you must do a 1/f compensation for the frequencies, but this is part of the "integration".
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16th October 2009, 01:51 PM  #503  
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Power output of 6pole Butterworth bandpass filter – First, the power spectrum is weighted with a squared magnitude of a bandpass filter response. And not which bandpass filter he uses. If I get the time and feel for it I can compare my amplitude smoothing with this
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16th October 2009, 01:56 PM  #504  
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gedlee = askbojesen?
Quote:
I suggest the following for a measurement: 1. Export unsmoothed FR or IR to your program 2. Your program > Smoothed FR/IR > HOLMImpulse 3. Compare Perhaps you can email me an IR and your smoothed FR  then I can do the comparison?
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16th October 2009, 03:29 PM  #505 
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16th October 2009, 03:54 PM  #506  
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If I smooth in Holm, can those curves be exported enmass like the IRs?
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16th October 2009, 07:58 PM  #507  
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16th October 2009, 08:10 PM  #508  
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16th October 2009, 10:44 PM  #509 
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The second pass is equivalent to a triangular weighting function, successive passes approach ever closer to a gaussian function. See this link for details: Relatives of the Moving Average Filter. That is the method I use for the fractional octave filters in REW.

17th October 2009, 12:47 PM  #510 
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From a numerical analysis point of view smoothing always reduces to some form of integration:
A'(fc) = integral [W(f)A(f)]/ integral[W(f)] over some limits f1 to f2 where fc is between them. W(f) is a weighting function of choice, typically symmetric about fc. Obviously, in the digital domain the integrals are replaced with their representative summations.
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