When recording audio in GarageBand, you may get distortion if your audio levels are too high (or "hot" in audio engineering parlance). This can be caused by one or more of the following instances:
- The audio source volume is set too high.
- The audio interface's gain level or output level is set too high.
- The Input volume in Sound preferences is set too high.
- The track or master volume level in GarageBand is set too high.
If you hear distortion in one of your Real Instrument tracks, play your sound while doing the following steps until you no longer hear distortion.
- Listen to your source (the instrument or thing that you're recording). If it sounds distorted outside of your computer, turn down its volume until the distortion stops. If your source sounds fine, keep reading.
- Check your audio interface—if you're not using an audio interface, skip to step 3. Depending on your device, you may have two areas to control volume—the input and the output gain. Adjust your level or levels accordingly, making sure that the meters on your device show a strong signal without signal peaks (if you see red lights on any level meter, turn down that gain level just until the red stops lighting). If you're still getting distortion, read on.
- Check the Input level in the computer's Sound preference pane. Set the "Input volume" slider so that the input level meter shows a strong signal without lighting up the last meter light. Still hear distortion? Then keep reading.
- In GarageBand, move the volume slider on the affected track to the point where you get a strong signal but the clipping indicators (the tiny dots to the right of the level meters) do not light. Check the master volume too—if the clipping indicators light up, turn down the volume level just until they no longer light. This should resolve the issue.