Apple Logic Pro X - Manual (Page 751)

Chapter 22 Surround in Logic Pro X 751
Surround format channel distribution
The following table provides details on the channels used by each of the supported
surround formats.
Surround format Channels used
Quadraphonic L - R - Ls - Rs
LCRS (Pro Logic) L - C - R - S
5.1 (ITU 775) L - C - R - Ls - Rs - LFE
6.1 (ES/EX) L - C - R - Ls - S - Rs - LFE
7.1 (3/4.1) L - C - R - Lm - Rm - Ls - Rs - LFE
7.1 (SDDS) L - Lc - C - Rc - R - Ls - Rs - LFE
Table key
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L = (Front) Left
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Lc = Left Center
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C = Center
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Rc = Right Center
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R = (Front) Right
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Lm = Left Mid
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Rm = Right Mid
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Ls = Left Surround (Rear Left)
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S = Surround (Rear Center)
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Rs = Right Surround (Rear Right)
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LFE = Low Frequency Effects
Surround bounce file encoders
Logic Pro X surround bounces are not encoded. Surround bounce files can be encoded in the
Compressor application, available in the Mac App Store, or with dedicated hardware devices and
other software.
Common surround encoded formats include:
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Dolby Digital: Dolby Digital (also known as AC3) includes the LFE channel. It is a compressed
format, commonly used for DVDs and digital terrestrial or satellite TV broadcasts. It is also
widely used for computer game soundtracks.
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Dolby Digital True HD: An uncompressed (or minimally compressed) high bit-rate format,
commonly used for Blu-ray discs and high definition digital terrestrial or satellite
TV broadcasts.
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SACD: Super Audio Compact Disc: The Sony-Philips version of DVD-A. SACD audio is stored in a
format called Direct Stream Digital, which has a sampling rate of 2.8224 MHz. SACD discs must
contain a stereo mix, but usually also offer a 5.1 mix (although this is optional).
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Pro Logic II: Pro Logic II uses two full-range rear channels, unlike the original Pro Logic (LCRS)
format. It does not, however, use the LFE channel. In other words, this is a 5.0 format, so simply
disable the LFE channel in Logic Pro X if you want to deliver a Pro Logic II soundtrack.
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DTS (Digital Theater Systems): Soundtracks generally sound better than Dolby Digital EX
equivalents because they use a 3:1 compression ratio, whereas Dolby uses a 12:1 ratio. Less
compression means more storage space is required on the delivery medium.