FFT Usage

[barry wilkins]

Does anybody have any examples of using the FFT fucntion on an oscilloscope on circuits ?
I read the post from my previous enquiry this looked similar to what I read on the internet ( Think it came from TEK).

Barry Wilkins

[hardwareguy]

Re: FFT Usage

Useful to represent a complex waveform in the frequency domain. It's a very fancy spectrum analyzer. It is useful anywhere it is desired to observe the frequency response of a system. Do FFT on the input and output of some signal processing circuit and it will give you a pretty good idea of what that circuit is doing frequency wise.

Would be *extremely* useful in circumventing embedded equalization systems in factory car audio systems where the manufacturer is unwilling to tell you what their DSP/EQ is exactly doing. Circumventing fixed equalizers is needed when fitting aftermarket speakers. Most simply junk the stock amp but sometimes the EQ is done in the head unit and this causes real problems if the head unit is vehicle specific and aftermarket replacements are unavailable or impractical. (split units with a sat nav screen and the controls as a separate unit come to mind...Nissan uses these but fortunately the EQ is in the Bose amplifier)