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by garyfirestorm 554 days ago
Not just that but the FRF calculation is slightly complex. You need to take into account windowing function, amplitude correction factor, sampling rate and block size of each measurement and %overlap… leakage is a very important thing in signal processing and spectral analysis. Also you need an anechoic environment to capture this, because you would be also capturing room reflections and characteristics of room acoustics.
3 comments

For the logarithmic sine sweeps (confunsigly also known as exponential sine sweeps) used here the standard method is to use an inverse filter to (de)convolve the sweep recording into an impulse response. No worries about windowing or leakage when using that.

This is sadly not very well documented process, but some open source implementations exist. E.g. https://github.com/maj4e/pyrirtool

Well, you don't need an anechoic environment for that. Just use a time window. Signal will be captured by mic before any reflection arrives. You won't be able to measure lows well, though. But ~300-20k Hz is fine.
> Also you need an anechoic environment to capture this,

They were talking about a home. /s