DSP! / THE LISTENING ROOM

Sound, made visible.

Choose a track or load a WAV, then press play and watch the signal.

RQ / AUDIO LABSTEREO MONITOR · 01
Awaiting a WAV file

Pick a built-in track, or load your own WAV below.

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Left channel analog VU meterLeft channel: −∞ dBFS. Zero VU is calibrated to -18 dBFS RMS.-20-10-7-5-3-2-10+1+2+320406080100VU−+RMSPEAKLEFT−∞ dBFS
Right channel analog VU meterRight channel: −∞ dBFS. Zero VU is calibrated to -18 dBFS RMS.-20-10-7-5-3-2-10+1+2+320406080100VU−+RMSPEAKRIGHT−∞ dBFS
LEFT / RIGHT · RMS LEVEL0 VU = −18 dBFS
80%

Both displays follow the output level.

300 ms

63% of the way in one τ. Smaller is faster.

FFT AUDIO SPECTRUML + R POWER
Audio frequency spectrum. The horizontal axis shows frequency in Hz; the vertical axis shows signal level from -90 to 0 dBFS.
STANDBYLOG FREQUENCY
8192-POINT FFT · 48 LOG BANDSYour own WAV files stay in your browser.
A note on the meters

The needles follow each channel's RMS amplitude with a first-order RC response: y += (target − y) × (1 − e−Δt/τ). The same τ controls rise and fall, independently of the display frame rate. A steady −18 dBFS RMS signal reads 0 VU; the red end of the scale is +3 VU. The small red peak light indicates a signal reaching digital full scale.

The spectrum combines left and right channel powers, so opposite-phase stereo signals remain visible. Frequency runs logarithmically from 20 Hz to 20 kHz, capped at the audio context's Nyquist frequency. Each bar shows the strongest FFT bin in its band, with a −90 dBFS floor.