Troubleshooting iShowU Audio Capture

Can't hear anything when trying to record app-audio? I've written up the steps I take when debugging app-audio problems. Note: this applies to iShowU Instant and iShowU Studio 2

Please check the following:

1 - Get up to Date!

First things first, make sure you are running the latest version of iShowU.

Goal: Making sure you're not chasing something that's already fixed.

1. Visit the SWB downloads page to get the latest. 
2. Make sure you have the latest version of the capture driver.
3. Make sure the iShowU Audio Capture driver is installed.

2 - Verify Audio Capture Driver isn't muted

Goal: Ensure all channels of the audio driver have their volume set, and don't have a rogue 'muted' flag set. I've seen this a bit over the years, so we check this first.

1. Open Audio Midi Setup, from /Applications/Utilities
2. Find 'iShowU Audio Capture'
3. Toggle the mute checkbox on ALL channels on both tabs (Input and Output). Do this even if the channel doesn't look muted. Toggle the mute flag, on every channel, regardless. I've seen cases where it doesn't look muted, but it is.
4. Slide all volume sliders to 100%, on all channels on both tabs (Input and Output). Same here. Slide it even if it looks like it's at 100%. By doing this you guarantee to set the volume of the channel, which is what we want to do.

3 - Verify sound is heard through the driver

Goal: Check that iShowU Instant (or Studio2) can 'hear' the audio coming though the driver. For this test we're going to play some music through iTunes and check that iShowU can 'hear' it, but seeing if it's application audio level meters bounce.

1. Quit any running iShowU Instant (or Studio 2)
2. Make sure your System Preferences | Sound | Output is set to speakers, or similar. Something you can hear.
   
3. Open iTunes, play some music. 
   1. You should hear it at this point, in whatever device you set audio to in (2).
4. Open System Preferences | Sound | Output
5. Change the default output device to iShowU Audio Capture.
   1. You should no longer hear music, even though it's playing. This is intended.
6. Open System Preferences | Sound | Input (yes, Input).
7. Click on the iShowU Audio Capture driver.
   1. You should see activity in its level meter. If you do NOT then there's a problem with the driver. 
   2. Of course; I assume here iTunes is happily playing something. Double check that (hh:mm:ss increasing, for example).
      
8. Revert the default output, by going to System Preferences | Sound | Output
9. Make sure that Output is set to speakers, or similar
10. Open up iShowU Instant (or Studio 2)
11. Click 'record app audio'.
12. You should see the level meter bounce in iShowU Instant (or Studio 2), and you may hear it if "monitor application audio" is selected.