iShowU, iShowU HD / HD Pro all use an audio capture driver called SoundFlower. The reason for this is that Apple doesn't provide a means to capture audio directly.
We've observed that sometimes SoundFlower's settings can get muddled up by other applications' own sound settings. This page provides a workflow to help you resolve any sound capture issues.
- Close all applications, including iShowU.
- Open iTunes and play some music, you should be able to hear it from your speakers or headphones.
- Open the Sound pane in System Preferences.
- Click the Output tab and Select Soundflower (2ch). This makes Soundflower the active output device.
You will no longer be able to hear audio playing from your speaker. This is normal for this test.
- Click the Input tab and Select Select Soundflower (2ch). If you look at the level meter it should be lighting up in time to the music. If you see the level lights flashing.
The steps makes sure your computer's overall audio levels are correct:
- Open Audio MIDI Setup (in your .../Applications/Utilities folder)
- On the left hand side you will see a list of your audio devices including Soundflower (2ch).
- Make sure all the Volume levels are high on all devices in both the inputs and outputs. Also check to make sure the mute checkboxes are unticked.
- Go back through Step 2. in your Audio System preference pane and check the input levels are lighting up? If this isn't happening Soundflower needs to be reinstalled
At this stage you can repeat the first steps to see if the audio is now appearing on the level meter shown on the Input side of the Soundflower 2ch window, within System Preferences | Sound.
To reset your settings back:
- Open the Audio pane in System Preferences.
- Click the Output Tab
- Choose Built-In Output, or Internal/External Speakers or Headphones
- Click the Input tab
- Select Internal microphone
When you turn on Record Application audio Soundflower switches the output from your Speakers to itself and then channels the audio to your speakers if you've got monitor audio turned on.
Open up iShowU and do a test recording of iTunes or Garageband playing music with Application Audio on. You should be able to hear and see the sound level bars in iShowU light up.