Spectrum analyzer is a good way to create exciting visual effects synchronized with music. [pyrograf] wanted a big one for display, so they started making their own things.
Esp32 microcontroller is the core of the construction. Its high clock frequency and dual core make it a high-performance work choice. The audio from the microphone is amplified and pumped into the analog input of esp32. The core 0 on esp32 then performs a fast Fourier transform on the input audio to determine the energy in each frequency band. Then, the results of FFT are passed to core 1, which is used to calculate the required animation and output them to a series of ws2812b LEDs.
However, what really shines about this building is the actual building. The LED is used to illuminate the large part of the spectrum of each LED. Combining the large pixel size with the smooth 30 Hz refresh rate on the LED results in a fairly large spectrum analyzer that looks really practical.
Over the years, we have seen some similar builds. Video after break.