quadscope · v1.0
QuadScope Manual
Waveform analyzer for Logic Pro and other DAWs — Scope, Spectrum, Harmonics, and XY/Goniometer in real time.
Getting Started
QuadScope makes audio visible. As an AU/VST3 plugin or standalone app it shows you in real time what your signal actually looks like — without changing the sound.
Requirements
- Apple Silicon Mac (M1 or newer)
- macOS 12 (Monterey) or newer
- A DAW with AU or VST3 support — or run it as a standalone app
Installation
- Download the
.pkginstaller and run it. - The plugin is installed automatically:
- AU →
/Library/Audio/Plug-Ins/Components/ - VST3 →
/Library/Audio/Plug-Ins/VST3/
- AU →
- Open your DAW. QuadScope appears in the plugin browser under Palmetshofer Audio.
Using QuadScope as a Plugin
- Insert QuadScope as an effect on any channel.
- QuadScope analyzes the audio flowing through that channel — the sound is not changed.
- Select a display mode at the top: Scope, Spectrum, Harmonics, or XY.
- Start playback — the plugin begins drawing immediately.
Tip: The BPM sync trigger only works as a plugin inside a DAW (standalone has no transport).
Using QuadScope as a Standalone App
- Launch QuadScope.app.
- Go to Options > Audio/MIDI Settings and select your input device.
- QuadScope will then analyze the live input from your computer (e.g., microphone or audio interface).
Controls
Display Modes
| Mode | What you see |
|---|---|
| Scope | Waveform in real time — classic oscilloscope view |
| Spectrum | Frequency spectrum (FFT) — which frequencies are how loud |
| Harmonics | The first 16 overtones (H1 = fundamental, H2–H16 = harmonics) |
| XY | Goniometer — L channel on X axis, R channel on Y axis |
Trigger Section
| Control | Function |
|---|---|
| Level (knob) | Threshold for the trigger point. The yellow line in the display shows the current position. |
| Rise | Trigger on rising edge — display restarts when the wave crosses the level going upward. |
| Fall | Trigger on falling edge. |
| Auto | Automatic trigger — a good starting point for most signals. |
| BPM | Trigger synced to the DAW tempo. Only available as a plugin. |
| Beat Division | Visible only with BPM trigger. Sets the displayed time range: 1 Beat / 1 Bar / 2 Bars / 4 Bars. |
Time and Level
| Control | Function |
|---|---|
| Time/div (0.1–50 ms) | Time window per grid division. Smaller = zoom in. Rule of thumb: bass 5–20 ms, highs 0.1–1 ms. |
| Gain (±24 dB) | Amplifies or attenuates the signal for the display only. No effect on the audio. Double-click to reset to 0 dB. |
Channel and Freeze
| Control | Function |
|---|---|
| L / R / L+R | Shows the left, right, or both channels. With L+R: L = cyan, R = amber. |
| Freeze | Holds the display. Audio continues normally. |
Spectrum / Harmonics Settings
Visible only when Spectrum or Harmonics is active:
| Control | Function |
|---|---|
| Smooth (0–1) | Smooths the FFT curve over time. 0 = immediate response, 1 = maximum smoothing. |
| Hann / Blkm / Flat | FFT window. Hann: good all-round (default). Blackman: fewer sidelobes. Flat Top: accurate level measurement. |
| 512 / 2048 / 4096 / 8192 | FFT size. Larger = better frequency resolution, slower response. Default: 4096. |
| dB / Lin | Spectrum only. Y-axis scaling: logarithmic (dB, default) or linear. |
Bypass
| Control | Function |
|---|---|
| Bypass (power button, top right) | Disables the analysis. Audio passes through unchanged. |
Cursor and Level Meter
Move the mouse over the display area — a crosshair appears with a readout box:
- Scope: time (ms) + amplitude
- Spectrum: frequency (Hz/kHz) + level (dB)
- Harmonics: harmonic number + frequency + level
- XY: L value + R value
The Level Meter at the bottom shows L and R levels. Green = OK, yellow = caution, red = clipping. The white line is peak hold (2 s), and a red dot indicates clipping (clears automatically after 3 s).
Glossary
Scope Time-domain display of the waveform. The trigger ensures the image is stable by restarting the drawing at the same point in the signal each time.
Spectrum (FFT) Frequency-domain display. Left = low frequencies (bass), right = high frequencies (treble). The height of each column shows the level in dB.
Harmonics Shows the first 16 overtones of the signal as bars. H1 = fundamental (the note you hear), H2–H16 = overtones (color the sound). A flute has almost only H1; a guitar or voice has many overtones.
XY / Goniometer Each sample is plotted as a point (X = L, Y = R). A narrow line pointing up-right means mono (L = R). A wide image means stereo. A line pointing down-right means out-of-phase — such signals cancel when summed to mono.
Trigger The mechanism that determines when the display restarts. Without a trigger, the waveform jumps around uncontrollably. With a trigger, it appears “frozen” at a stable position.
FFT (Fast Fourier Transform) A mathematical process that decomposes a time-domain signal into its frequency components. FFT size determines how many samples are used per analysis window — larger = finer resolution but slower response.
Peak Hold Shows the most recently reached peak level for a short time (white line in the level meter, peaks in the spectrum). Helps capture brief transients the eye would otherwise miss.
Troubleshooting
The waveform keeps jumping around. Set the trigger to Auto. If that does not help, raise the Trigger Level slightly — the trigger should respond to the actual signal, not background noise.
The spectrum is very jittery. Increase Smooth. For stable signals (sine waves, pads, drones) 0.7–0.85 is a good starting point. For drums and transients, keep it at 0.2–0.4 to preserve the visible dynamics.
Small “bumps” to the right of the main peak (even though only one tone is playing). This is not a signal artifact — it is FFT sidelobes. At smaller FFT sizes the main peak broadens and the Hann window produces visible sidelobes that look like a chain of hills on the logarithmic frequency axis. Fix: switch FFT to 2048 or 8192. The sidelobes drop below the dB scale.
A wide noise floor around -60 dB and below. A normal FFT effect: the smaller the FFT size, the higher the numerical noise floor per bin. Fix: FFT 8192 + Smooth 0.85 — the image will then look just as clean as other analyzers.
No display even though audio is playing. Check whether the Bypass button is active (the power icon at the top right must be lit). In standalone mode: go to Options > Audio/MIDI Settings and confirm the correct input device is selected.
BPM trigger does not react. The BPM sync trigger only works as a plugin inside a DAW that provides transport information. In standalone mode no transport is available — use a different trigger mode instead.
Credits
QuadScope v1.0 Developed by Palmetshofer Audio — palmetshofer-audio.com