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Table Of Contents
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
L = (Front) Left
Lc = Left Center
C = Center
Rc = Right Center
R = (Front) Right
Lm = Left Mid
Rm = Right Mid
Ls = Left Surround (Rear Left)
S = Surround (Rear Center)
Rs = Right Surround (Rear Right)
LFE = Low Frequency Eects
Surround bounce le encoders
Logic Pro X surround bounces are not encoded. Surround bounce les 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:
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.
Dolby Digital True HD: An uncompressed (or minimally compressed) high bit-rate format,
commonly used for Blu-ray discs and high denition digital terrestrial or satellite
TV broadcasts.
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 oer a 5.1 mix (although this is optional).
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.
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.