Configuring Audio Hardware and Drivers

To get sound into and out of your computer, you must have an audio interface. An audio interface is a device that converts digital audio from your computer to analog waves that speakers can broadcast. In the other direction, an audio interface converts analog waves into digital audio you can save and manipulate on your computer. Either way, an audio interface has only one purpose: It converts sound between the digital and analog domains.

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The audio interface that comes with your computer is sufficient for using Logic, but it offers only a stereo eighth-inch input and a stereo eighth-inch output. These connections are usually reserved for attaching headphones to your computer or for basic recording purposes. They do not offer professional sound quality.

To communicate with its audio interface, a computer needs a small software application called a driver. All audio interfaces have their own special drivers, and in most cases you'll have to install that driver before Logic will recognize it. But once that driver's installed, there's very little else you need to do. Logic will automatically recognize your audio interface along with all available inputs and outputs (most audio interface manufacturers have a support section on their Web sites where you can download drivers).

However, situations might arise where Logic unexpectedly uses the wrong audio interface. For example, if Logic starts playing from the speaker on your computer, it's using your computer's built-in audio controller instead of your audio interface. Fortunately, this situation is easy to fixjust select your audio interface's driver from Logic's Audio Drivers Preferences pane.

NOTE

Logic's Core Audio represents a massive step forward for audio on the Macintosh. In OS X, several applications can stably share a single audio interface at the same time. For example, you can now play a Logic arrangement, preview a video in QuickTime, and audition Apple Loops in iTunesall at the same time!

Selecting an Audio Driver

1.	Open the Autoload Song you saved at the end of the previous lesson. NOTE If you don't have this file, you can follow along using the file named 12Begin.lso, located in the APTS_Logic_7 > Song Files > Lesson 12 Project Files folder.
2.	Choose Audio > Audio Hardware & Drivers. The Audio Drivers Preferences pane opens. The Core Audio tab is automatically selected, and Logic will choose either the built-in audio driver or your audio interface from the Driver menu. If you have more than one audio interface attached to your system, you can choose a different interface from the one that Logic has automatically selected.
3.	From the Driver menu, choose the audio interface you want to use. If you selected a different audio interface from the one Logic automatically chose, you will be presented with a new dialog that asks you to reboot Logic.
4.	Click Try (Re)Launch. You do not actually need to reboot Logic, because the audio interfaces can switch in the background while Logic remains open.

Increasing Available Audio Tracks

By default, Logic gives you 24 audio track channels. If you need more, you can increase this number using the Max. Number of Audio Tracks setting in the Audio Drivers Preferences pane.

1.	If you closed the Audio Drivers Preferences pane, reopen it now by choosing Audio > Audio Hardware & Drivers. The Audio Drivers Preferences pane opens. In the middle of the Core Audio tab is a preference that says Max. Number of Audio Tracks.
2.	Set this number to the number of audio tracks you'd like to make available. For Logic to lock in this change in the maximum number of audio tracks, you need to relaunch the Core Audio driver.
3.	In the top left corner of the Core Audio tab, click the Enabled check box to disable Core Audio.
4.	Click the Enabled check box a second time to reenable Core Audio. Once again an Alert pops open to tell you to reboot Logic.
5.	Click the Try (Re)Launch button. Core Audio is reenabled, and you now have access to the number of tracks you specified in the Max. Number of Audio Tracks preference.
6.	Close the Preferences window.