MOTU 24Ai, User Manual

Page: 61 / 92

W O R K I N G W I T H H O S T A U D I O S O F T W A R E
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Lower latency versus higher CPU overhead
Buffer size has a large impact on the following:
■
Monitoring latency
■
The load on your computer’s CPU
■
Responsiveness of transport controls and effect
knobs in AudioDesk, Digital Performer or other
audio software.
■
Real-time virtual instrument latency.
The buffer setting presents you with a trade-off
between the processing power of your computer
and the delay of live audio as it is being patched
through your software. If you reduce the size, you
reduce monitoring latency, but significantly
increase the overall processing load on your
computer, leaving less CPU bandwidth for things
like real-time effects processing. On the other
hand, if you increase the buffer size, you reduce the
load on your computer, freeing up bandwidth for
effects, mixing and other real-time operations.
Figure 7-7: When adjusting the buffer size to reduce monitoring
latency, watch the ‘processor’ meter in Digital Performer or
AudioDesk’s Performance Monitor. If you hear distortion, or if the
Performance meter is peaking, try raising the buffer size.
If you are at a point in your recording project where
you are not currently working with live, patched-
thru material (e.g. you’re not recording vocals), or
if you have a way of externally processing inputs,
choose a higher buffer size. Depending on your
computer’s CPU speed, you might find that settings
in the middle work best (256 to 1024).
Transport responsiveness
Buffer size also impacts how quickly your audio
software will respond when you begin playback,
although not by amounts that are very noticeable.
Lowering the buffer size will make your software
respond faster; raising the buffer size will make it a
little bit slower.
Effects processing and automated mixing
Reducing latency with the buffer size setting has
another benefit: it lets you route live inputs through
the real-time effects processing and mix
automation of your audio software.
WORKING WITH ON-BOARD MIXING AND
EFFECTS
Your MOTU interface provides powerful mixing,
EQ, compression and reverb, which can operate
hand-in-hand with your host’s mixing
environment. For example, your MOTU interface
can serve as a monitor mixer, routing channels to
musicians, or it can serve as an integrated
extension of your host’s mixing environment. You
can even save a particular mixing configuration as
a preset for future recall. For details, see “Mixing
tab” on page 17.
SYNCHRONIZATION
You may encounter situations in which you need to
synchronize your audio software and your MOTU
interface to other components of your system. For
details, see “Synchronization” on page 40.