Apple Soundtrack Pro 2 - Manual (Page 297)

Chapter 9 Mixing Surround Sound 297
Connecting Physical Outputs
To hear the six discrete channels of surround sound that Soundtrack Pro can provide,
you need external audio hardware that supports multiple physical outputs. At a
minimum, this would include a multichannel audio interface and a 5.1-channel
surround sound speaker system (totaling six speakers). For more information about
audio interfaces, see “
Setting Up an Audio Interface ” on page 485.
To connect physical outputs for monitoring surround sound:
1 Connect the audio interface to your computer.
For detailed information on connecting your audio interface to your computer, see the
documentation that came with the audio interface.
2 Double-click Audio MIDI Setup in the Utilities folder, then choose the audio interface
from the Default Output pop-up menu.
For more information, see “ Setting the Audio Input and Output ” on page 22.
3 Connect your 5.1-channel surround sound speakers to the appropriate outputs of your
audio interface.
Soundtrack Pro uses the SMPTE/ITU standard for routing output channels.
For detailed information on connecting external speakers to your audio interface, see
the documentation that came with the speakers.
Stereo Mixdown
If you have set up a project for surround mixing, including surround panners and
surround channel assignments, but you do not have sufficient output jacks for
surround playback, Soundtrack Pro automatically provides a surround-to-stereo
mixdown of what would otherwise be sent to jacks 1-6. This stereo mixdown follows
the Dolby guidelines: the Ls and Rs channels are attenuated by 3 dB and mixed into the
Left and Right channels. The Center channel is also attenuated by 3 dB and mixed
evenly into the Left and Right channels. The LFE channel is discarded.
Audio Interface Output Speaker
1 Left
2 Right
3 Center
4 LFE
5 Left Surround (Ls)
6 Right Surround (Rs)