Normal
Re: FIR filtersThanks. I suspect the initial window might be redundant, since the Gaussian window in the frequency domain is doing all the work and its time tails are low in amplitude near where the transform window would be rolling down. (I just tried a ~1/6th octave Gaussian freq filter at about 10 kHz in Matlab for a 32768 length transform and the time tails of the IFFT are below -100 dB.)I think the Hilbert transform here is converting the linear-phase Gaussian IR into a minimum phase for each band. And in a colour plot of a single impulse, this should give a single sided plot (i.e. not symmetric as in Raimonds). Is that what you see? I may be wrong. I think just a IDFT/IFFT of each band (followed by log magnitude and pretty colours) will give a symmetric plot like Raimonds.Cheers,Michael
Re: FIR filters
Thanks. I suspect the initial window might be redundant, since the Gaussian window in the frequency domain is doing all the work and its time tails are low in amplitude near where the transform window would be rolling down. (I just tried a ~1/6th octave Gaussian freq filter at about 10 kHz in Matlab for a 32768 length transform and the time tails of the IFFT are below -100 dB.)
I think the Hilbert transform here is converting the linear-phase Gaussian IR into a minimum phase for each band. And in a colour plot of a single impulse, this should give a single sided plot (i.e. not symmetric as in Raimonds). Is that what you see? I may be wrong. I think just a IDFT/IFFT of each band (followed by log magnitude and pretty colours) will give a symmetric plot like Raimonds.
Cheers,
Michael
