The purpose of this project was to understand the relationship between the frequency and Time Domains. The Audio Analyzer is capable of taking in a song input, separating the high and low frequencies and lighting up LEDs in correspondence with those frequencies

To create this design, my team and I had to undergo several steps before we could analyze music. First, we broke the project into four major parts: The Summing Amplifier, High and Low Pass Filters, Peak Detector and LED Driver.

Summing Amplifier - Uses an inverting op-amp to combine the left and right signals from the inputted song.

High and Low Pass Filters- To separate the high from the low frequencies, we designed filters using Sallen-Key Architecture. We decided to choose the same corner frequency(305 Hz) for both filters.

Peak Detector - To create the peak detector, we put a diode in series with a capacitor(10uF) in order to output a DC voltage equivalent to the peak value of an applied AC input so the LED would flash in accordance with the music's peak values.

LED Driver - The LED driver was designed to keep the LEDs off whenever the input voltage is below the threshold and then turn on only once the MOSFET has entered into saturation and is above the threshold voltage.

Once we understood the desired functionality, we Analytically determined the best component values to achieve our goals. We Numerically tested our design using Multisim software. Once our design was verified we populated the PCB and tested it extensively.

After thorough testing and debugging, our Audio Analyzer performed as desired. To the right is a video depicting our Design processing Pump It Louder by the Black Eyed Peas.