The objective of this project was to construct an audio equalizer that allowed the user to adjust the volume of different frequency bands. The audio equalizer would use several subsystems to accomplish this goal. First, filters would separate the input audio signal into different frequency bands. Next, control subsystems with adjustable gain would control the volume of each individual frequency band. Then, the individual bands would be combined back together and a power amplifier would ensure the adjusted audio signal is strong enough to drive audio through the speaker.

• Low pass filter used to isolate frequencies below 320 Hz

• Band pass filter used to isolate frequencies between 320 Hz and 3.2 kHz

• High pass filter used to isolate frequencies above 3.2 kHz

• Amplifiers adjust gain of each band, then adjusted signals are combined back together

  • When all equalizers turned down, 1 peak to peak voltage sine wave input produces an output of less than 15 mV_RMS at 200 Hz, 2 kHz, and 10 kHz

  • When all equalizers turned up, 1 peak to peak voltage sine wave produces an output of 100 mV_RMS at 200 Hz, 2 kHz, and 10 kHz

  • Ripple measurement is less than 15 mV_RMS from 200 Hz to 10 kHz

• Power amplifier output power is > 400 mW from 200 Hz to 10 kHZ with an input of 1 peak to peak voltage sine wave