The "library" article titled "Loudspeaker measurement technique" describes a potentially very useful technique for evaluating loudspeaker frequency response, but need a bit of updating. The article was written for the ADC-216, which was as noted in the article is replaced by the PicoScope 4262. The ...

Can someone explain how the PicoScope measures IMD? I'm used to a setup where you'd introduce two frequencies, say 1000 and 60 Hz, and then measure intermodulation signals at 1060 Hz etc. What is the PicoScope doing to measure IMD and what is it using as a reference for calculating percent or dB?