M-AUDIO 2626 ユーザーズマニュアル

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User Guide
10
ProFire 2626
Software Returns – This block represents the audio 
outputs of your audio application   Software returns 
can be routed to the DSP Mixer and the Router (both 
described below) 
DSP Mixer – This is the 18 input, 16 output DSP 
mixer contained within the ProFire 2626 interface   
The block features a dashed line because the DSP 
mixer can be completely bypassed by the user if 
desired 
As shown in the illustration above, the mixer’s 18 input 
channels accept signals from any of the hardware 
inputs or software returns   See the “Mixer” section of 
the “Control Panel Application” chapter to learn how 
to configure and use the DSP mixer 
In cases where the computer is unable to run with 
sufficiently small buffer size settings (i e , the software 
monitoring latency is too high), the DSP Mixer can be 
used instead to achieve near-zero latency monitoring 
of your input signals 
Router – The Router is a device that lets you select 
the source of each hardware output on ProFire 2626   
These sources include any pair of hardware inputs, 
the main output of the DSP mixer or any of its seven 
auxiliary sends, and any available software return pair 
The router is an extremely useful tool since it allows 
you to reconfigure how audio streams flow out of the 
interface without having to physically re-patch the 
cables connected to the back of the interface 
Hardware Outputs – These are the physical outputs 
of ProFire 2626 including the eight 1/4” analog jacks, 
two ADAT ports, and the S/PDIF connector   The 
Router (see above) lets you select the source of each 
hardware output pair 
About Software Returns:
The term “Return” has its roots in analog recording, 
where input sources (Microphones, Instruments, etc.) 
are connected to large format mixing consoles, routed 
to multi-track reel-to-reel tape machines for recording 
and then returned to the mixing desk. This allows the 
recording engineer to hear the recorded signal from tape 
while the recording is still in process. This way, problems 
with the recording (e.g. tape imperfections, or distorting 
signals) can be detected in real-time. 
While recording systems have evolved greatly over the 
years and DAW applications have become more popular 
for recording and playback, the concept of returning 
signals from your recording device has not changed.  In 
the case of the ProFire 2626, the output of your audio 
software (the recording device) is returned to the ProFire 
2626 Router section – hence the term “software returns.” 
Signals returning from your software to ProFire 2626 
can then be sent to the DSP mixer and/or any hardware 
output of your choosing.
 
Why use the DSP Mixer?
Most audio applications include mixing and monitoring 
functionality and you may be wondering why you 
would want to use the ProFire 2626 DSP Mixer for 
monitoring instead of the DAW application.  The main 
reason for using the DSP Mixer is that software-based 
audio applications suffer from a phenomenon known 
as “latency.”  Latency is the amount of time it takes your 
audio signals to pass through the computer (and its DAW 
software) and become available at the hardware outputs.  
This delay is usually quite small and is measured in 
milliseconds, but it may be large enough to distract a 
performer who wishes to record while monitoring through 
software.
The amount of latency varies depending on many factors 
including your computer’s performance and buffer size 
settings.  Powerful computers with fast processors may 
allow you to run your sessions with very small buffer size 
settings, providing virtually imperceptible latency.  In this 
case, you can use your application’s software monitoring 
features and bypass the ProFire 2626 DSP Mixer.