To hear sound from a microphone, an electric guitar, or another instrument in GarageBand, you must set the input source for the device (the microphone or instrument). You can set the input source when you add a track, or set it for the selected track in the Track Info pane.
- If you are using your computer’s built-in microphone, choose Built-in Microphone from the Input Source pop-up menu.
- If you are using a device connected to your computer’s audio input port, choose Built-in Input from the Input Source pop-up menu.
- If you are using a device connected to a USB port on your computer, choose the name of the device from the Input Source pop-up menu.
- If you are using a device connected to an audio interface, choose the channel number for the microphone from the Input Source pop-up menu.
Make sure the format matches the device. If the device has stereo output, choose a Stereo pair of channels; otherwise, choose a Mono (monophonic) channel.
If the device does not appear in the Input Source menu, choose GarageBand > Preferences, click Audio/MIDI, then choose the device from the Audio Input pop-up menu.