Audio Hijack Pro offers a System Audio source, to make it possible to capture all audio, instead of just one application's audio. While capturing audio on an application-level is recommended for most cases, capturing System Audio may be useful in some instances.
Initial Setup
The first time you use the System Audio component, you may need to install Instant On. To do this, create a new session and set the source selector to System Audio. Now click the Install button in the pane, and the Instant On installer will open.
Once Instant On is installed, the following steps will allow you to hijack and record System Audio.
Step 1) Create a new session, and set the source selector to System Audio.
Step 2) Click Hijack, and all audio will flow through Audio Hijack Pro, and then out your speakers. That's it.
Once you've got this set, you can create adjust or record any and all audio on your machine.