Channel Count Under Core Audio; Various Information - RME Audio Fireface UCX User Manual

17.5 Channel Count under Core Audio

At a sample rate of 88.2 or 96 kHz, the ADAT optical input and output operates in S/MUX mode,
so the number of available channels is reduced from 8 to 4.
At a sample rate of 176.4 and 192 kHz, the ADAT optical input and output operates in S/MUX4
mode, so the number of available channels is limited to 2.
It is not possible to change the number of Core Audio devices without a reboot of the computer.
Therefore whenever the Fireface changes into Double Speed (88.2/96 kHz) or Quad Speed
mode (176.4/192 kHz) all devices stay present, but become partly inactive.
Single Speed
Analog 1 to 8
SPDIF coax L / R
SPDIF opt LR / ADAT 1/2
ADAT 3 to 8

17.6 Various Information

The driver of the Fireface requires at least Mac OS 10.5, as special USB functions are used that
are not available in older versions of the operating system.
Via >System Preferences/ Audio-MIDI Setup< the hardware can be configured for the system
wide usage. Programs that don't support card or channel selection will use the device selected
as Standard-Input and Standard-Output. (Soundstudio, Mplayer, Amplitube etc.).
In the lower part of the window, the audio hardware's capabilities are shown and can be
changed in some cases. On the record side no changes are possible. Programs that don't sup-
port channel selection will always use channels 1/2, the first stereo pair. To access other inputs,
use the following workaround with TotalMix: route the desired input signal to output channels
1/2. In the channel settings of outputs 1/2 activate Loopback. Result: the desired input signal is
now available at input channel 1/2, without further delay/latency.
Use Speaker Setup to freely configure the playback to all available channels. Even multichan-
nel playback (Surround, DVD Player) can be set up this way.
34
Double Speed
Analog 1 to 8
SPDIF L / R
SPDIF opt LR / ADAT 1/2
ADAT 3 to 4
User's Guide Fireface UCX © RME
Quad Speed
Analog 1 to 8
SPDIF L / R
SPDIF opt LR / ADAT 1/2
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