View modes

WAVE

Time-domain waveform with edge trigger. Use TIME/DIV and VOLT/DIV to zoom.

SPEC

Frequency spectrum on a log scale from 20 Hz to Nyquist. Orange markers show peak hold.

BOTH

Split view — waveform in the top half, spectrum in the bottom half.

Controls

TIME / DIV

Zooms the waveform window from ~3 ms to ~43 ms per screen.

VOLT / DIV

Vertical gain. 1.00× is unity; increase to amplify small signals.

TRIGGER LVL

Rising zero-crossing threshold. Keeps the waveform locked in place. Adjust if the trace rolls.

SPEC SMOOTH

Spectrum time-averaging (0 = raw and noisy, 0.97 = heavily smoothed). Affects SPEC and BOTH views.

FREEZE

Pauses the display while keeping audio capture active.

Trace options

• Color — CYN / VLT / ORG / WHT. Also changes background color.
• LINE — single-pixel trace. Clearest for high-frequency signals.
• FILL — filled waveform area. Good for showing envelope shape.
• DOTS — individual sample points. Useful for seeing sample density.

Audio input

• Click SCAN to enumerate devices without starting capture — useful if your interface was plugged in after page load.
• Select a device from the dropdown before or after hitting START. Switching while running reconnects instantly.
• DAW / software routing (macOS) — install BlackHole, set your DAW output to BlackHole, select BlackHole as the input here.
• DAW / software routing (Windows) — use VB-Audio Virtual Cable the same way.
• Hardware interface — appears in the device list automatically once mic permission is granted.