Apple Pro Training Series Logic Pro 7 and Logic Express 7 [Electronic resources]

Martin Sitter; Whitney Walker

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Using the Freeze Function

Freezing tracks is a feature that greatly increases Logic's power to process audio. If your system-resources monitor (the CPU window) begins peaking too close to the top of its meter, you can click the Freeze button and then keep working.

Freeze performs an offline bounce for each frozen track. In other words, it renders the track and its plug-ins into a freeze file, and then automatically plays back this freeze file instead of the original one. After freezing, the track's plug-ins are temporarily deactivated, and they will place virtually no strain on your system until you unfreeze the track.

The Freeze button appears on every audio track and Audio Instrument track in the Arrange window, and it looks like a little snowflake. In a few moments you'll click this button to freeze a few tracks. But before doing so, there's something you need to know…

Setting the Song Start and End Markers

Freeze files are always rendered between the song start and song end markers. This has significant implications for short songs, like the one you're working on, because if you click the Freeze button now, you'll have to sit and wait as Logic freezes a lot of empty space at the end of the song. Fortunately, this is a waste of only time, not disk space. Logic automatically trims all silence from the end of a freeze file. Still, time is money, so let's take a moment to snug up the song start and end markers to the active part of the song.

NOTE

The song start and end markers also form the default bounce Region.

Grab the song start marker and drag it to bar 0. (The song start marker looks like a white-outlined rectangle at the beginning of the Bar Ruler.)

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Adding a bar of silence to the start of the song gives you four beats to add MIDI control-change and automation data to configure your MIDI instruments before the song starts playing.

NOTE

Clicking the song start marker has a side effect: All Objects in the Arrange area are automatically selected.

Like the song start marker, the song end marker is a white rectangle in the top portion of the Bar Ruler. However, the song end marker is currently way down the Bar Ruler. You can scroll down until you find it and then drag it forward to the end of your song, but a far easier method involves using the Transport window's song end setting.

Choose Windows > Transport (Cmd-7).

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The Transport window opens. In the bottom right corner of the Transport window is the Song End box, which displays the number of the bar where the song currently ends.

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NOTE

The song end setting is available only in the Transport windowthe Arrange window's Transport panel does not give you access to it.

Double-click the song end setting.

A text box appears.

Type

27 into the text box that appears, and press Return.

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Why 27? A quick glance at the Arrange area shows that our song finishes at bar 25. Adding two additional bars gives a little extra room to catch reverb and delay tails, or long release settings from Audio Instruments.

NOTE

Depending on your arrangement, your song might end at a different bar than the one pictured. If so, set the song end setting to two bars after the last Region finishes playing.

After you press Return, the song end marker jumps to bar 27.

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Close the Transport window to get it out of the way.

Freezing Tracks

Freeze files are created using 32-bit floating-point processing to preserve the full signal quality of Logic's DSP effects and Audio Instrument plug-ins. In other words, frozen tracks sound exactly the same as unfrozen ones, so you don't have to worry about changing your sound when you freeze.

NOTE

The word

freeze is a pun.

Freezing tracks

frees your processor for other calculations. Get it?

With the song start and end markers appropriately set, it's time to freeze a track. Let's practice with the Bongo track to see how the process works. But first, you'll need to insert a few effects plug-ins so that you have something to freeze. To do so quickly, let's use a channel strip configuration.

In the Arrange window, select the Bongo track.

The Arrange channel strip updates to display the channel strip for the Bongo track.

Lesson 10, "Automating the Mix," but for now, close the Channel EQ to get it out of the way.

Play the song and listen to the inserted channel strip effects.

As the song plays, pay particular attention to the CPU window's Audio meter.

Stop playback.

In the Track column, click the Bongo track's Freeze button.

NOTE

When you click the Freeze button, the track's Record Enable button disappears, because it's not possible to record onto a frozen track.

Nothing happens right away. Logic waits until the next Play command to freeze the track, which provides you the opportunity to freeze more than one track at the same time.

Press the spacebar to initiate a Play command and, by association, the freeze process.

The SPL races through your song, following the process of the Freeze function, and the Freezing Progress dialog appears.

Logic renders out the track, along with all associated plug-ins assigned to its Insert slots. Until you unfreeze the Bongo track by clicking the Freeze button again, Logic will play the Bongo freeze file instead of the original audio track.

The freeze file itself is stored in a new Freeze Files folder that Logic automatically creates in the same folder as the song's project file. This freeze file remains only as long as the track is frozen. The instant you unfreeze this track, Logic deletes the new freeze file, so you don't need to worry about filling up your hard disk with unneeded frozen tracks.

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10.

Press the spacebar to play the song.

The Bongo track sounds just as it did before, and you can still hear the effect of the inserted DSP plug-ins, but a quick glance at the CPU window shows that the strain on your CPU is lower.