Forum Replies Created
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24 July 2020 at 3:30 am #238I looked over your system and project files.
The export format was set for “Binary file (32 bit, int)”, not “Binary file (32 bit, float)”. This will likely cause miniDSP to see NaN when importing.
Regarding filtering, there was an 2nd order all-pass IIR at 38 Hz and a 2nd order maximum-phase all-pass on the “FIR Phase Adjust” tab but the tab’s “Enable” was unchecked. Try removing the IIR filter and checking the “Enable” on the “FIR Phase Adjust” tab. This should give you a FIR that unwraps the LF phase for the measurement in the project.
Best,
EA Support
22 July 2020 at 9:46 pm #237Can you please email info at eclipseaudio.com and attached one of the bin files (that causes NaN) with miniDSP and the FIR Designer M system and project files used create the bin file?
Best,
EA Support
22 July 2020 at 9:28 am #235What format are you exporting?
I think miniDSP loads 32bit floating point binary files.Best,
EA Support
17 July 2020 at 9:28 pm #233Great. High delay in measurements is often the problem.
Best,
EA Support
17 July 2020 at 7:08 am #231In the editor, click the IMG button and embed a link to an image sharing site.
Best,
EA Support
16 July 2020 at 6:08 pm #226Can you please provide a screenshot of the Import tab and Auto Phase tab?
Best,
EA Support
14 July 2020 at 10:38 pm #223>> Is it correct to assume that this loudspeaker is displaying non-minimum phase behavior
>> around the crossover region when one looks at the 2-nd order all-pass response of its
>> phase response?Yes.
>> Can the phase adjustments being done around the crossover region, to flatten the phase
>> response, be deemed to be “maximum phase” corrections seeing that we are inverting an
>> all-pass response?Yes. But remember this is just one loudspeaker. Each loudspeaker is different.
>> Is the flattening of both the magnitude (EQ boosting) and phase response around the
>> crossover region not going to introduce audible artifacts like pre-ringing?Maybe. Linear-phase brick-wall crossovers also have pre-ringing but it’s rare that people say they think they can hear it.
>> Can the same EQ concepts be readily applied in correcting the room transfer function
>> displaying non-minimum phase characteristics at the listening/measurement position?Yes but I’d suggest doing a literature search on the topics of room impulse response correction and inverting room impulse responses; maybe in the Audio Engineering Society resource library.
Best,
EA Support
12 July 2020 at 11:36 pm #202In the tutorial the 200 Hz High Shelf is maximum phase. Try changing it in your project from minimum to maximum phase and see what happens.
Best,
EA Support
7 July 2020 at 9:00 pm #192That’s correct. Those checkboxes have not yet been updated to allow colour changing.
EA Support
3 July 2020 at 8:06 pm #188We have considered this. Different miniDSP plugins have different requirements. Some don’t need the biquad label for each biquad and some do.
We’ll consider adding an user option for this.
Best,
EA Support
18 June 2020 at 11:35 am #180Hi Sunil,
Even though your measurement system might be doing specific time windowing, the IR still has both loudspeaker phase and high delay which manifests as high phase slope when exporting as freq/mag/phase TXT. (I’m guessing this high delay is the time-of-flight across your chamber, plus soundcard buffer delays.)
In FIR Designer there is no error to give. The TXT file HAS phase and so the loading process is doing the best it can to interpolate the TXT file to the finer resolution FFT spacing. The high phase slope is the problem, and in this case is causing spurious distortion in the calculated IR. (You can see this on the FIR Designer Import tab if you expand the time axis and zoom the vertical axis.) If you truely want to ignore phase, then you can set all the phase values to 0 deg in the TXT file. (FWIW SMAART spectrum measurements come across to FIR Designer with 0 deg phase.)
In this situation it’s always best to avoid using log-frequency-spaced freq/mag/phase data – no matter how fine in resolution – for transfer between programs. Conversion to this format looses information which then causes problems when trying to reconstructed the impulse response – which is what FIR Designer is doing. It’s always best to transfer using an impulse response or time format, where information doesn’t get lost. (E.g. AFMG ETM files, or the time impulse as TXT or WAV.
>> And since Auto Mag should be trying to work on matching measured magnitude to target only, I do not see the relation to phase.
Auto Mag works with complex input and calculates the magnitude using either power averaging or complex averaging across frequency. You’re correct that power averaging should avoid issues of high phase slope but the additional distorting (added by the import interpolation process due to the high phase) is also causing problems in the Auto Mag.
I guess we could add an option to completely ignore phase on import, but it’s not something people normally want. When doing any filtering on a loudspeaker, most folks want to see both the phase of the filtering and the effect – both magnitude and phase – of the filter on the loudspeaker measurement.
Best,
EA Support -
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