MACKIE 400F - Manual (Page 24)

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ONYX 400F
ONYX 400F
Clock Source
There are three choices for selecting a clock source.
• INT (Internal): This is the default selection. The
Onyx 400F operates using its own internal ex-
tremely accurate, low-jitter clock. Select INT when
you want the 400F to serve as the master clock in a
system of digital devices.
• W.C. (Word Clock): The Onyx 400F operates using
the clock from the device that is connected to the
WORD CLOCK IN (18) jack on the 400F rear panel.
Select W.C. when you want the 400F to be a slave in
a system of digital devices.
• S/PDIF: The Onyx 400F syncs to the S/PDIF digital
input (21) signal.
Note: If there is no clock present at the WORD
CLOCK IN jack or no signal at the S/PDIF IN, you
cannot select W.C. or S/PDIF and the clock source
defaults to INT.
DSP Mixer
This turns the DSP Matrix Mixer on and off.
• Off: When the DSP Mixer is turned off, the 400F
retains the last settings it had when the DSP Mixer
was on. All the Output tabs are “greyed” out and the
controls cannot be adjusted.
You might leave the DSP Mixer off if your computer
has a lot of processing power and you are not con-
cerned about the low-latency contributed by rout-
ing the audio through the DAW software application
and back to the Onyx 400F for monitoring. Another
scenario is if you are just mixing and using the 400F
as a 10x10 audio interface without using any extra
routing (i.e., headphone monitoring).
• On: When the DSP Mixer is turned on, the Matrix
Mixer is enabled and the fi ve Output tabs are active
and selectable. Each output tab controls the mix for
a pair of outputs (i.e., 1/2, 3/4, etc.). These mixes
are routed to the ten line outputs on the rear panel
of the Onyx 400F. Each mix is comprised of the ten
inputs (4 mic/line, 4 line, 2 S/PDIF) and two chan-
nels returned from the DAW.
The inputs to the Onyx 400F are split off into two
directions after the A/D converters: one path goes
to the DSP Mixer and the physical outputs on the
400F, and the other path goes to the ASIO/Core Au-
dio inputs 1-10 of the DAW over the FireWire con-
nection. These are not affected by the DSP Mixer.
This lets you use the DSP Mixer for tracking a band
and creating zero-latency headphone mixes for
the talent using the line outputs routed through a
headphone distribution amplifi er, while sending the
tracks to the DAW for recording.
Another scenario is for overdubbing, where you are
adding another track to some tracks already re-
corded, which are routed from the DAW to the 400F
via the DAW Outputs.
Headphones
This lets you select which outputs are routed to the
headphone outputs. This selection applies to both
headphone outputs 1 and 2 (and to the Control Room
outputs).
• Mirror Outputs 1/2: Outputs 1 and 2 are routed to
the left and right headphone outputs. The talent
is hearing the same mix in the headphones as the
engineer is in the Control Room outputs.
• Mirror Outputs 7/8: Outputs 7 and 8 are routed to
the left and right headphone outputs. This allows
you to create a separate mix for the talent, different
from a control room mix you might have streaming
out of outputs 1 and 2.
S/PDIF Format
There are two standard digital audio formats in com-
mon use: AES/EBU (Professional) and S/PDIF (Con-
sumer). The audio data is the same for either format,
just the non-audio data bits (subcode) are different.
In almost all cases, using the Consumer setting will
work just fi ne. Occasionally, a S/PDIF device may want
to see the Professional subcode and cause problems
when using the Consumer setting. If you fi nd that the
digital audio is not being tranmitted or received cor-
rectly, try using the Professional setting.
Note: If connecting a device equipped with an AES/EBU
digital output to the S/PDIF input on the 400F using an
AES/EBU-to-S/PDIF converter, set the S/PDIF format to
professional.
Buffer Size
The buffer size is related to latency, which describes
the amount of time it takes for audio to get in and out of
your software application. The lower the buffer size, the
lower the latency, and the faster audio can get into and
out of the software application. However, a low buffer
size requires more resources from your computer, so you
need to fi nd a happy balance between fi nding the lowest
latency you can attain before the computer begins to
have trouble routing and recording audio (e.g., drop-
outs, pops, distorted audio).
Many DAW software applications have an ASIO con-
trol panel. In Tracktion 2, it is in the “Audio Devices”
window in the “Settings” tab. Click the “Show ASIO
control panel” button to open the ASIO control panel
for the Onyx 400F . The buffer size in the ASIO control