I like investigating real-world phenomena through sound, and this time I am checking out lamps. I have following scheme:
I have noticed that each lamp type distorts 50hz mains tone in its own unique way. More like same string would produce variable tones on a different guitar hulls. Now I want to obtain that distortions. So channel 2 (right) passes mains noise undistorted, and channel 1 (left) records that signal distorted.
Signal2 (R) has quite fixed level, which changes a little (stable 50hz/230v mains voltage in my country, with change no more than 5%). But Signal1(L) can change alot, dependant on how far did i fixed lamp away from panel, and how powerful and efficient the particular lamp is.
Question is - how to substract original signal2, if i dont know signal1 level, or the level can vary?
PS. This would be done digitally on a PC, using
C language. But before substrating second recording from first, I need to get a clue on how to "normalize" first signal levels to match those of a second, at 50hz main harmonic?
PPS. for those who was curious how samples could look like: