Hi Stephan,
To calculate IMD for audio, you would typically need to perform a spectral analysis of the audio signal and measure the levels of the intermodulation products. One approach could be to use the Fast Fourier Transform (FFT) to obtain the frequency spectrum of the audio signal. Then, you can identify the intermodulation products by looking for peaks in the spectrum at frequencies that are the sum and difference of the original audio frequencies at different orders.
You could follow the below steps:
- Read the audio signal into MATLAB using the "audioread" function.
- Apply a windowing function to the audio signal to reduce spectral leakage.
- Compute the FFT of the windowed audio signal using the "fft" function.
- Convert the FFT result to a power spectrum by taking the magnitude squared of the FFT result.
- Identify the peaks in the power spectrum that correspond to the intermodulation products and measure the levels of the intermodulation products.
you can also look at https://www.mathworks.com/help/dsp/ref/distortionmeasurementsconfiguration.html
