Mixing & Effects¶
ScratchTrack provides a mixer, per-track effects chains, and Audio Unit plugin support to shape your sound.
The Mixer¶

Switch to Mixer Mode to see all your tracks as channel strips side by side.
Channel Strips¶
Each track has a channel strip with:
| Control | Description |
|---|---|
| Volume Fader | Adjusts the track level from -60 dB to +6 dB |
| Level Meter | Shows real-time audio levels (RMS and peak) |
| Mute | Silences the track |
| Solo | Isolates the track (mutes all non-soloed tracks) |
| Track Name | Displayed at the bottom of the strip |
Master Channel¶
The master channel strip controls the final stereo output:
- Stereo level meters (Left and Right channels)
- Master volume fader (-60 dB to +6 dB)
- Master effects chain
Level Meter Colors¶
The level meters are color-coded to help you monitor levels:
| Color | Meaning |
|---|---|
| Green | Safe level — plenty of headroom |
| Yellow | Caution — approaching clipping |
| Red | Clipping — reduce volume to avoid distortion |
Audio Unit Plugins¶
ScratchTrack supports AUv3 (Audio Unit v3) plugins for both effects and instruments.
Adding Effects¶
- Open the plugin browser for a track.
- Browse or search for installed Audio Units.
- Filter by type:
- Effects — Reverb, delay, EQ, compression, etc.
- Music Effects — Specialized processing
- Instruments — Synthesizers, samplers (for MIDI tracks)
- Generators — Signal generators
- Click to add the plugin to the track's effects chain.
Plugin Controls¶
Once a plugin is added, you can:
- View and adjust plugin parameters
- Use the plugin's native UI or ScratchTrack's parameter sliders
- Reorder plugins in the effects chain
- Remove plugins from the chain
Master Effects¶
You can also add plugins to the master bus to process the final mix:
- Select the master channel.
- Add effects the same way as track effects.
Master effects apply to the combined output of all tracks.
Missing Plugins¶
Missing plugins
If you open a song that uses plugins not installed on your system, ScratchTrack shows a warning dialog listing the unavailable plugins. The song still opens — the missing plugins are simply bypassed.
Track Volume and Pan¶
Volume¶
Adjust track volume using:
- The volume slider on the track header (0–100%)
- The volume fader in the mixer view (-60 dB to +6 dB)
Both controls are linked — changing one updates the other.
Mute and Solo¶
- Mute — Silences a track. You can mute multiple tracks.
- Solo — Plays only the soloed track(s). All non-soloed tracks are silenced. You can solo multiple tracks to hear them together.
Spectrum Analyzer¶

ScratchTrack includes a spectrum analyzer for visualizing the frequency content of your mix:
- Opens in a separate window
- Shows real-time FFT analysis of the master output
- Frequency labels and grid lines for reference
- Particle visualization driven by audio magnitude
Next Steps¶
- Version Control — Save your mix state and experiment with branches
- Exporting Your Song — Export your final mix as WAV