This was my first time ever using an oscilloscope. I used it mainly to test if my frequency filters worked.

I built my own inductors in order to then build my own highpass and lowpass filter circuits. I used online calculators to figure out what values of inductance and capacitance I needed.

Here you can see the power supply, two amplifier boards, my filter breadboard, one large driver, and two tweeters from the back of the speaker.

I can't remember if these are the final values I chose for crossovers, but this is the kind of calculation I was doing.