Allen & Heath
20
XONE:4D User Guide
MIDI CONTROL
MIDI (musical instrument digital interface) is a standardised protocol for
communication between electronic music devices as well as between those
devices and computers. Two identical banks of MIDI controls are provided on
either side of the mixer section. These bring control of remote performance
equipment such as computer-based sound manipulation and sequencing, samplers,
effects and even lighting right to the mixer control surface. The function of the
controls may be identified using overlay sheets, samples of which are supplied
with the Xone:4D.
The control banks comprise both linear and rotary faders, rotary encoders with
integrated switches, push button switches with and without light ring indicators,
and large dedicated jog wheels with four position switches. A footswitch socket
and the 15-pin Game port provide control voltage input, which produce further
MIDI output from foot pedal, joystick and custom-wired controllers. Operation
of these controls does not affect any audio signals directly, but is automatically
translated into MIDI messages according to a pre-configured MIDI ‘map’. The
MIDI channel number, map and other functions are selected during the start-up
configuration procedure. Two MIDI maps are available to suit the various
performance software applications currently available. Further details are
provided later in this guide.
In addition to the dedicated MIDI controls, some of the DJ mixer functions also
output MIDI messages when operated. These include all switches with light rings,
the filter frequency controls, the crossfader, and BPM start/stop and clock. The
MIDI data is sent out of the mixer via the rear panel MIDI out and Game port
sockets, and is simultaneously transferred to a connected computer via the USB
interface. The MIDI surface has two ‘pages’, allowing all of the MIDI controls (with
the exception of the crossfader), to be mapped twice.
SOUNDCARD
The 20-channel USB2.0 soundcard is built into the mixer to ensure the highest
performance and lowest noise. 24-bit converters are used at a maximum
sampling rate of 96kHz, together with low latency ASIO drivers supplied by Allen
& Heath.
There are 4 stereo (8 mono) analogue and 1 stereo (2 mono) digital inputs to the
PC/Mac from the Xone:4D, and 4 stereo (8 mono) analogue and 1 stereo (2
mono) digital outputs from the PC/Mac to the Xone:4D.
The soundcard input block diagram is shown overleaf.
DESCRIPTION
