Apple Logic Pro 7 (TDM Guide) - Manual (Page 12)

12 Chapter 1 Audio Hardware and Drivers
DAE Settings
The DAE parameters can only be set after activating the DAE. To do so, check the
Enabled box in the upper left corner of the DAE pane. You will then have access to the
following parameters:
Global Bit Depth
This parameter allows you to choose between 16 bit or 24 bit playback and recording.
Note: The DAE does not allow the use of 16 and 24 bit files simultaneously.
PT HD Type
This parameter allows you to define the number of tracks for your PT HD or HD Accel
system. Each entry in the pop-up menu allows you to define the required number of
tracks, based on the number of PT HD DSPs that you wish to use (and actually have) in
your system.
MIX Card Type
This pop-up menu option determines the number of tracks that are possible from your
MIX Card system. Options are
32 Tracks or 64 Tracks . Setting it to 32 Tracks will save
resources and is highly recommended, when using DTDM in parallel with MIX
hardware.
TDM Setup Indicator
The TDM Setup Indicator is a small status window that shows the current TDM process,
such as when inserting a TDM plug-in, for example. This parameter enables you to
switch the display of this window on or off.
About Sample Rates and Bit Depths
Some audio hardware, such as Pro Tools HD, supports high sampling rates of 88.2, 96,
176.4, or 192 kHz. Logic Pro supports these high sample rates. The sample rates can be
selected in the
Audio > Sample Rate menu. Note that these higher sample rates
require two or four times the hard disk space, and that the audio engine will be
required to perform two or four times as fast as a 44.1 kHz rate. You should consider
that the improvement in audio quality of 96 kHz recordings, compared with 44.1 kHz,
is fairly minor. More significant differences can be heard between 16 and 24 bit
recordings. Many audio engineers consider 44.1 kHz, 24 bit recording to be the best
balance between sound quality, and efficient use of resources. For modern DVD
production higher sample rates may be required.
Logic allows the simultaneous playback of audio files of different bit depths (16 and
24) within the same song, using a native audio engine.
If you want to use both bit depths natively, please ensure that the DAE engine is set
to 24 bit.