# Sessions and the Audio Grid

## Sessions

As mentioned on the Audio Hijack Basics page, Sessions are reusable collections of settings used to capture audio. Once a Session is configured to your liking, you'll run it and audio will be sweetened and recorded as you specify.

Sessions are automatically saved for re-use, and all saved Sessions are shown in the Sessions tab of the Home Window.

## Understanding the Audio Grid

The Audio Grid is the heart of each Session. To set up a Session, two or more Blocks are added from the Block Library to the Audio Grid. Connections will be made automatically between nearby Blocks, and you can always experiment to get the exact audio pipeline you're after. If you need to, just select Undo to revert undesired changes.

When a Session is activated, audio from the sources selected will flow from left to right through the Blocks in the Audio Grid. The audio is show in orange as it flows through the audio pipeline. Each Block in the chain will adjust or record the audio according to its settings. To hear the audio you're recording as you record, don’t forget to add an Output Block!

### The Block Library

On the right side of each Session is the Block Library. This library holds all available Blocks for use in the Audio Grid. Every Session will need at least one Source Block, which will bring audio in, and one Output Block, to record audio or pass it along to your speakers. In addition, Sessions can use audio effects to manipulate and improve audio. Audio Hijack comes with a powerful collection of over a dozen built-in effects. In addition, Audio Unit effects provided by Mac OS X and those available from third-parties are also be recognized and shown by Audio Hijack. Finally, Meter Blocks provide visual meters so you can see how audio is flowing.

Configuring Blocks is a fairly straightforward process, and the library itself provides a quick explanation of most Blocks. Some audio effects may have more complex settings which will require some audio knowledge to use, but you can always experiment to get just the sound you're looking for.

### Laying Out Blocks

The sequence of Blocks you lay out will determine what audio is affected by Audio Hijack, and how it's affected. Block layouts can be very simple, like this layout where audio from the computer's built-in microphone is being recorded.

Layouts can also be more complex, and more powerful. Here, audio from two different inputs is being adjusted with different audio effects. Each input is then recorded separately, before a third recording combining the two is made. This layout will result in three different audio files.

### Block Settings and Popovers

Blocks can be laid out in nearly limitless ways to create the audio pipeline you're after. Once you've laid out your Blocks, you may also wish to tweak their individual settings. A few of the simple Blocks have controls right on their face.

The Volume Block, with on-face controls

Other Blocks have their controls available in their popover. Click these Blocks to get a popover showing the Block's controls and settings.

The Recorder Block's popover

Here you can see the Recorder Block's popover, one of Audio Hijack's most powerful popovers. It offers two controls up top, and three sections below. In addition to what's visible, each section has additional settings which can be revealed with a click. While there are many settings in this popover, they're easy to understand.