User Manual-Mac

INSTALLING THE PCI-424 HARDWARE
31
HD192 INPUT AND OUTPUT CONNECTIONS
Here are a few things to keep in mind when making
connections to the HD192 inputs and outputs.
Connect them all, if you like
All of the HD192’s inputs and outputs can be active
simultaneously.
+4 dB analog inputs/outputs
The HD192’s analog connectors are calibrated at
+4 dB, so if you are plugging in a microphone,
you’ll need a mic preamp of some kind (or a
connection to a mixer with a mic pre).
Mixing live inputs with CueMix DSP
As you plan the I/O routing for your HD192
interface, refer to “Mixing live inputs with CueMix
DSP” on page 29. CueMix DSP™ is a flexible
DSP-driven mixing and monitoring matrix that
provides the same near-zero monitoring latency as
today’s latest digital mixers, and it will help you
determine the mixing and monitoring scheme for
your studio.
HD192 AES/EBU
If you would like to transfer stereo audio digitally
between the HD192 and another device that has
AES/EBU I/O, connect it to the HD192’s AES/EBU
jacks with balanced, AES/EBU grade audio cables.
Connecting the HD192’s AES/EBU jacks to RCA
SPDIF connectors via adaptors is not
recommended. The HD192’s AES/EBU connectors
support 24-bit digital audio at any sample rate up
to 100 kHz.
Internally, the HD192 is “hard-wired” to provide a
maximum of 12 independent inputs and outputs.
Both the analog section and AES/EBU section
share these I/O resources, with AES/EBU taking up
one pair of the 12 virtual ins and outs. For example,
in the MOTU PCI Audio Console, you could use
channels 1 through 10 for analog input and
channels 11-12 for AES/EBU input. AES/EBU
completely takes over the inputs, entirely disabling
the corresponding analog inputs. For output,
however, AES/EBU mirrors its corresponding pair
of analog outputs, so you can send the same stereo
mix to both analog and AES/EBU simultaneously.
Therefore, if you plan to use AES/EBU at the same
time as the analog inputs/outputs of the HD192,
think about which analog pair you are least likely to
need while transferring audio via AES/EBU. Plug
those analog ins/outs into the sockets on the rear
panel that correspond to the channel numbers
you’d like to use for AES/EBU. (The channels
numbers you use for AES/EBU don’t matter. Use
whatever you like.)
AES/EBU clock and sample rate conversion
The HD192 AES/EBU section is equipped with
real-time sample rate converters on both input and
output. In addition, the AES/EBU section has its
own clock crystal, allowing it to run at a completely
independent sample rate from the HD192 system
clock. Together, these features provide a great deal
of flexibility in making digital transfers. For
example, you can:
Figure 3-7: You can connect up to 12 analog inputs and outputs, plus stereo AES/EBU, to the HD192.