DigiDesign Mbox User Manual

Chapter 2: Windows Configuration 13
Configuring Pro Tools LE
Pro Tools System Settings
Pro Tools LE lets you adjust the performance of
your system by changing system settings that af-
fect its capacity for processing, playback, and re-
cording
In most cases, the default settings for your sys-
tem provide optimum performance, but you
may want to adjust them to accommodate large
or processing-intensive Pro Tools sessions.
Hardware Buffer Size
The Hardware Buffer Size (H/W Buffer Size) con-
trols the size of the hardware cache used to han-
dle host processing tasks such as Real-Time Au-
dioSuite (RTAS) plug-ins.
◆ Lower Hardware Buffer Size settings reduce
monitoring latency, and are useful when you are
recording live input.
◆ Higher Hardware Buffer Size settings allow for
more audio processing and effects, and are use-
ful when you are mixing and using more RTAS
plug-ins.
To change the Hardware Buffer Size:
1 Choose Setups > Playback Engine.
2 From the H/W Buffer Size pop-up menu, select
the audio buffer size, in samples.
3 Click OK.
CPU Usage Limit
The CPU Usage Limit controls the percentage of
CPU resources allocated to Pro Tools host pro-
cessing tasks such as Real-Time AudioSuite
(RTAS) plug-ins.
◆ Lower CPU usage settings reduce how much
Pro Tools processing affects other CPU-intensive
tasks (such as screen redraws), and limit the
amount of processor resources available for
Pro Tools tasks. They are useful when you are ex-
periencing slow system response, or when run-
ning other applications at the same time as
Pro Tools.
◆ Higher CPU Usage Limit settings allocate
more processing power to Pro Tools, and are
useful for playing back large sessions or using
more real-time plug-ins.
The maximum CPU Usage Limit is 85 percent
for single-processor computers, and 99 percent
for multi-processor computers. (The 99 percent
setting dedicates one entire processor to
Pro Tools.)
In addition to causing slower screen re-
sponse and monitoring latency, higher
Hardware Buffer Size settings can affect the
accuracy of plug-in automation, mute data,
and timing for MIDI tracks.
Playback Engine dialog for Mbox
Increasing the CPU Usage Limit may slow
down screen response on slower computers.

DigiDesign Mbox Specifications

General

Type	Audio Interface
Mic Preamps	2
Phantom Power	Yes
Bit Depth	24-bit
Software Included	Pro Tools LE
Connectivity	USB
Simultaneous I/O	2 x 2
Analog Inputs	2 x XLR/TRS combo
Analog Outputs	2 (1/4" TRS)
Headphone Output	1 x 1/4" TRS
Sample Rate	48 kHz