Spectrum Analyzer

Visualize audio frequencies from your microphone in real-time. This spectrum analyzer uses Fast Fourier Transform (FFT) to display a live frequency spectrum. Click Start to enable your microphone. The surround sound test tests each speaker individually and in sequence to confirm your surround system is balanced.

Press Start Microphone to begin real-time analysis.
— Hz
Dominant Frequency
— dB
Peak Level
Low High

Your microphone audio is processed locally and never sent to any server.

How a Spectrum Analyzer Works

A spectrum analyzer converts a time-domain audio signal into its frequency components using the Fast Fourier Transform (FFT) algorithm. Instead of showing how the audio changes over time, it shows how much energy is present at each frequency at any given instant. Pink noise from the noise generator sounds more natural than white noise and is commonly used for speaker break-in.

A larger FFT window size gives better frequency resolution but slower time response — useful for identifying sustained tones. A smaller window updates faster, better suited to transients like drum hits. Check your microphone is picking up sound correctly with the free microphone test.

Frequency Bars Mode

Displays the magnitude of each frequency band as a vertical bar. Taller bars mean more energy at that frequency. Useful for identifying dominant tones, resonances, and noise peaks.

Waveform Mode

Shows the raw time-domain waveform of the audio signal. Reveals the shape and amplitude of the sound wave over time, and helps identify clipping or distortion.

Use Cases
  • Check microphone frequency response
  • Identify background noise sources (hum, hiss, fan noise)
  • Visualize music and speech in real time
  • Troubleshoot acoustic problems in a room