After routing channel strips to an output (see Routing Channel Strips to an Output) and defining a bounce range (see Defining the Bounce Range), you should define the bounce parameters in the Bounce window.
Choose File > Bounce from the main menu bar to bounce output channel strips 1 and 2.
Click the Bounce button on the relevant output channel strip.
Several global options are available in the Bounce window, regardless of the file types being bounced.
PCM file (SDII, AIFF, (Broadcast) Wave, or CAF format)
M4A: AAC file
Burn: CDDA file
If you click the Destination file format name, rather than select the file format checkbox, you can set a number of preferences in the area to the right (preferences change based on your chosen Destination file format). For example:
If the Cycle function is engaged, the boundaries are set to the locator positions.
If a selection is made in the Arrange window, the boundaries are set to the selected area.
If neither of the above is valid, the boundaries encompass the entire Logic Express project.
In any case, you can adjust the start and end positions manually—for example, if you want to take into account a MIDI sound module (mixed via an aux channel strip) that falls outside the bounce start and end positions.
Tip: It’s often a good idea to set the end position of the bounce a little bit past the end of the last region. This ensures that reverb tails and echoes from delay plug-ins are not chopped off. The amount of extra time needed depends on the effect settings used.
As you adjust the Start and End position parameters, you are shown the hard disk space requirements for the bounced file above the Cancel and Bounce (Bounce & Burn) buttons.
Click the PCM name and select its checkbox in the Destination pane to access the following options:
Logic Express allows the bouncing of MP3 (MPEG-2, Audio Layer 3) format files. This well-known data reduction format for digital audio signals was developed by the Fraunhofer Institute, and allows high compression rates while maintaining reasonable audio quality (depending on the compression rate). MP3 is a widely used standard for audio file exchange via the Internet.
Because encoding an MP3 file equates to a loss of audio quality, you should not use MP3 files during production if you have access to the same audio data in linear formats such as AIFF, WAV, or SDII.
Bounced PCM files are also used for encoding to MP3/M4A: AAC. Note that this occurs before dithering takes place.
Note: If the selected sample rate is higher than 48 kHz, a temporary copy of the bounced PCM file is created (with an automatic sample rate conversion to 48 kHz) before encoding. This conversion takes place because the MP3 format does not support sampling rates higher than 48 kHz.
If the PCM option is unselected in the Destination pane, a temporary PCM file is bounced as a source for encoding to MP3/M4A: AAC or burning to a CD, according to the options selected in the PCM pane.
Select the MP3 name (and select its checkbox) in the Destination pane to access the following options:
To enhance audio quality, provided you can afford the extra file size, choose:
96 kbps for mono streams
192 kbps for stereo streams
You can choose higher rates, but the quality improvement afforded by bit rates above 96/192 kbps is nominal.
Unfortunately, not all MP3 players can accurately decode VBR-encoded MP3s, which is why this option is turned off by default. If you know that your target listeners can decode VBR-encoded MP3s, you can turn this option on.
All entries are made by double-clicking the Content column fields to the right of the corresponding ID3 Frame column entry, and typing in your text.
Select the “Use default values” checkbox to display default settings for certain Content column entries. For example, the Project Title and Tempo (Beats Per Minute) are automatically filled in.
Selecting the “Use default values” checkbox also sets the Initial Key pop-up menu to the first entry shown in the global Signature track. This is “default: C” if no key has been set for the project. You can choose another key from the menu.
Click the M4A: AAC name and select its checkbox in the Destination pane to access the following options:
Unfortunately, not all media players can accurately decode VBR-encoded files, which is why this option is turned off by default. If you know that your target listeners can decode VBR-encoded files, you can turn this option on.
Note: This parameter is only available when the AAC codec is chosen.
If the selected sample rate is higher than 48 kHz, a copy of the bounced PCM file is created (with an automatic sample rate conversion to 48 kHz) before encoding. This conversion takes place because the M4A: AAC format does not support sampling rates higher than 48 kHz.
Choose the Burn: (CDDA or DVDA) name (and select its checkbox) in the Destination pane to access the following options:
Logic Express can directly burn Red Book audio to blank CDs or DVD-Audio to blank DVDs.
Note: Enabling the Burn option automatically disables the PCM > Split Stereo option (following a warning message). This is because CD or DVD-Audio only makes use of interleaved stereo files.
The “Simulate write only” option, as the name suggests, simulates a CD/DVD burn, but does not write data to the blank media. This can be used either alone or in conjunction with the “Write as multi session” option (if burning a CD).
The “Write as multi session” option is only available when CDDA is chosen in the Mode pop-up menu. This option allows you to add a data session to the same CD at a later date—to add the project folder, for example.
This pop-up menu allows you to choose between any recognized CD/DVD burners connected to your system.
Note: If your system contains multiple burners, the first one detected is chosen as the default.
The first time you use the Speed pop-up menu, a request is made to the burning mechanism, which may take a while. Once the scan is complete, you can choose from the available speeds.
The Dithering pop-up menu is only available when CDDA is chosen in the Mode pop-up menu. Use of the Dithering parameter is recommended when bouncing 24-bit recordings into 16-bit files.
Note: If you attempt to switch the PCM Resolution to 16 Bit when in DVDA Burn Mode, DVD burning is automatically disabled (following a warning).
Clicking the Bounce & Burn button initiates the bounce, and burns the audio to a CD or DVD.
Note: Following confirmation of the file location(s), you may see further dialogs that ask if you want to overwrite existing files. Use these as necessary.
The Media Status field indicates the type of media chosen in the Device pop-up menu.
The field below indicates the current PCM pane settings (if applicable).
A further field, above the Cancel and Bounce & Burn buttons, indicates the amount of disk space required, and the time (length, shown in hours, minutes, and seconds) of the bounce area.
Note: You cannot directly alter any information shown in these areas.