If you get "No audio inputs available" when clicking the IN selector on an audio track in the sequencer it could be that you need to create an aggregated audio driver, to combine the inputs and outputs of your audio interface/sound card into a single audio driver.
To create an Aggregated Device, proceed as follows:
- Open “Audio MIDI Setup” in the “Utilities” folder in “Applications”.
- Make sure the "Audio Devices" window is open.
- In the lower left corner, click the [plus] button and create a new aggregated device.
IMPORTANT: Also MANUALLY RENAME your new aggregated device!
- Tick the “Use” check boxes for each of the Audio Devices (inputs and outputs) you want to use.
- In Reason, go to Preferences/Audio and select your new aggregated driver.
If you still get no audio input signal, please have a look at this article.