CHAPTER
A B O U T T H E P C I E - 4 2 4 S Y S T E M
6
1
About the PCIe-424 System
OVERVIEW
The PCIe-424 core system is a computer-based hard disk
recording system for Mac OS and Windows that offers 24
simultaneous inputs and outputs per Audio Wire cable,
expandable to 96 inputs/outputs. A core system consists of a
PCI card connected to a standard 19-inch, single-space,
rack-mountable audio interface.
The system includes AudioDesk™, full-featured audio
workstation software for Mac OS that supports both 16-bit
and 24-bit recording at any standard sample rate up to 192
kHz.
For Windows, a WDM driver is included for compatibility
with audio applications that support standard multi-channel
WDM and Wave drivers.
Also included is an ASIO driver for multi-channel operation
with Steinberg Cubase and other ASIO-compatible software.
The PCIe-424 card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The 2408mk3 interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The 24I/O interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
The HD192 interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
16-bit and 24-bit recording. . . . . . . . . . . . . . . . . . . . . . . . . . . 9
AudioDesk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Digital Performer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Other Audio Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
A computer-based system . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
THE PCIE-424 CARD
A PCIe-424 core system ships with a single PCI audio card
called the PCIe-424. The card features a custom processor, a
powerful DSP chip, four 6-pin Audio Wire connectors and
an ADAT SYNC IN connector.
High definition audio
The PCIe-424 system can operate at the following high
sample rates: 44.1, 48, 88.2, 96, 176.4 and 192 kHz. All
MOTU PCIe-424 audio interfaces support rates up to 96
kHz. In addition, the HD192 interface offers analog
recording and playback at 176.4 or 192 kHz.
Audio Wire expansion
The PCIe-424 card provides four Audio Wire jacks, which
are used to attach MOTU PCI audio interfaces to the card
installed in the computer. Each Audio Wire is capable of
transmitting 24 simultaneous channels of 96 kHz digital
audio input and output or 12 simultaneous channels of 192
kHz input and output.
Up to four MOTU PCI audio interfaces can be connected to
a single PCIe-424 card for a maximum of 96 possible input
and output connections. All MOTU PCI audio interfaces
(including the 2408mk3, 24I/O and HD192) can also be
“mixed and matched” on the PCIe-424 card, along with
legacy interfaces, such as the 2408, 2408mII, 1296, 1224, 24i
and 308.
Audio Wire carries a proprietary communication protocol
between the card and the external I/O to handle the
extremely low latencies required by the system. The heart of
the PCIe-424 card is a custom-programmed VLSI chip
capable of simultaneously processing all 96 inputs and
outputs (192 channels total) at samples rates up to 96 KHz.
At 176.4 or 192 kHz, this chip can process 48 simultaneous
channels of input and output.
The custom chip handles all of the system’s I/O processing,
freeing up the host computer’s processing bandwidth for
real-time DSP effects and hard disk I/O.
CueMIx DSP
The PCIe-424 card features CueMix DSP™, a flexible
DSP-driven mixing and monitoring matrix that provides the
same near-zero monitoring latency as today’s latest digital
mixers. CueMix DSP™ allows you to connect keyboards,
synth modules, drum machines, and even effects processors
and then monitor these live inputs with no audible delay and
no processor drain on the host computer’s CPU. The CueMix
DSP engine resides on the PCIe-424 card, so it works across
all interfaces connected to the card. The included CueMix
Console software provides an on-screen mixer that gives you
hands-on control of your monitor mix, regardless of what
audio software you prefer to use. Digital Performer users
have the additional option of controlling CueMix DSP
directly within Digital Performer’s mixing environment.
CueMix DSP completely eliminates the buffer latency
associated with monitoring on host-based recording
systems.
Sample-accurate synchronization
The PCIe-424 card’s standard 9-pin ADAT SYNC IN
connector provides sample-accurate synchronization with
all ADATs or other ADAT Sync-compatible devices
connected to the system. For example, if you digitally
