User`s guide

REDUCING MONITORING LATENCY
90
MONITORING LIVE INPUT
There are two ways to monitor live audio input
with an 828mkII: 1) through the computer or 2) via
CueMix™ DSP hardware monitoring. Figure 12-1
on page 90 shows method 1, which allows you to
add effects processing such as reverb and guitar
amp effects via plug-ins in your audio software. See
the next section, “Adjusting the audio I/O buffer”
for details about how to reduce — and possibly
eliminate — the audible monitoring delay that the
computer introduces.
Figure 12-2 shows how to use CueMix™ DSP
hardware-based monitoring, which lets you hear
what you are recording with no monitoring delay
and no computer-based effects processing. (You
can add effects later, after you’ve recorded the live
input as a disk track.) See “CueMix DSP hardware
monitoring” later in this chapter for details on how
to use CueMix DSP with your audio software, or
with the included CueMix Console software.
If the material you are recording is suitable, there is
a third way to monitor live input: use both methods
(Figure 12-1 and Figure 12-2) at the same time. For
example, you could route vocals to both the
computer (for a bit of reverb) and mix that
processed signal on the main outs with dry vocals
from CueMix DSP.
ADJUSTING THE AUDIO I/O BUFFER
A buffer is a small amount of computer memory
used to hold data. For audio interfaces like the
828mkII, buffers are used for the process of
1. Live input (from mic, guitar, etc.)
enters the MOTU interface.
Mac
2. Mic signal goes immedi-
ately to the computer (dry,
with no effects processing).
3. Mic signal is
‘patched thru’ back to
the audio interface
with reverb or other
plug-in effects, if any.
Figure 12-1: There are two ways to monitor live audio inputs with an 828mkII: 1) through the computer or 2) via CueMix™ DSP hardware
monitoring. This diagram shows method 1 (through the computer). When using this method, use your host software’s buffer setting (or, under
Mac OS 9, the 828mkII’s ‘Samples Per Buffer’ setting in the MOTU FireWire Audio Console) to reduce the slight delay you hear when monitoring
the live input, but don’t lower it too much, or your computer might get sluggish.
4. Mic signal (with plug-in
processing, if any) is routed
to the main outs (or other
outputs that you’ve specified
in the software).
!828 Manual/Mac Page 90 Tuesday, May 27, 2003 1:45 PM