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Hi Everyone,

We just released FIR Designer 2.11 and FIR Designer M 1.3 - both with new IIR filter modes and IIR mode conversion. It's now easier than ever to bring loudspeaker preset IIR settings from any of the 5 branded modes into miniDSP products. Choose the IIR mode, enter the filter settings and export to TXT for miniDSP to get the raw filter coefficients.

More details about the IIR modes are at
eclipseaudio.com/2019/09/06/iir-conversion/
and check out the release notes pages for information about other feature updates.

Kind regards,
Michael

From @Musan

I am getting somewhat conflicting graphs when trying to calculate the phase response of a second order all pass filter in FIR Designer and another simulation program. FIR Designer uses Bandwidth (BW) to calculate the Q of the filter and in this other program one can insert Q directly. The phase response displayed by both programs is not in agreement and I tried using this site; www.sengpielaudio.com/calculator-bandwidth.htm to work out the equivalent of each but still the phase graphs are not exactly the same.

I am keen to know the formula used for BW calculation in FIR Designer.

Perhaps an option to choose either BW or Q in the program Preferences could be made available.

Many brands use different interpretations of BW and/or Q.
eclipseaudio.com/2019/09/06/iir-conversion/
Even the sengpielaudio calculator only covers one interpretation and conversion.

The "General (Lake)" mode uses the Lake definition of BW.
soundforums.net/community/threads/q-to-l...idth-converter.5089/

Also, the "General (Lake)" mode's parametric and shelf filters match the Lake processors, where the parametric filter uses the Orfanidis method.
eclipseaudio.com/2019/03/15/iir_filter_emulation/

Yes, for the "General (Lake)" mode there is a setting in Preferences call "Filter definition" which can be set to BW or Q.

Kind regards,
Michael

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Regards,

Thanks Michael