The SparkFun Spectrum Shield splits a stereo audio input into 7 frequency bands per channel using two MSGEQ7 graphic equaliser ICs. Read the amplitude of each band via your Arduino's ADC to create sound-reactive projects — from LED visualisers and light shows to sound-activated motors, relays, and more.

The shield features two 3.5 mm (1/8″) stereo jacks: one for audio input and one as a pass-through output, allowing you to connect it in-line between your audio source and speakers without interruption. Updated to the Arduino R3 layout.

Key Features

• Dual MSGEQ7 ICs – 7-band frequency analysis on both left and right channels
• Stereo Input – 3.5 mm jack for audio source connection
• Pass-Through Output – 3.5 mm jack to forward audio to speakers/headphones
• Arduino R3 Layout – Standard shield form factor
• ADC Readable – Band amplitudes read directly via Arduino analogue pins

Ideal For

• Audio visualisers and LED light shows
• Sound-reactive art installations
• Music pattern detection
• Sound-activated projects (motors, relays, lighting)

Package Contents

• 1× SparkFun Spectrum Shield (headers not included)

Resources

• Hookup Guide
• MSGEQ7 Datasheet (PDF)
• Schematic (PDF)
• Example Code and Design Files (GitHub)