|ATL M2820 Mixing Console
The worldfs first 192-kHz, 32-bit
digital mixer—an incredibly intuitive and robust console that delivers
exquisite, high-resolution audio with near-zero latency
Powered by a 40-bit FPGA engine, the new
M2820 Mixing Console from Acoustic Technical Laboratory Inc. offers unmatched
audio quality and standout reliability. Boasting a remarkable 192-kHz sampling
rate and 32-bit I/O, itfs sound is simply second to none. Marking the next
phase in mixer evolution, the M2820 features 28 input channels and 20 output
channels, all connected via an advanced routing system that takes full
advantage of ATLfs time-proven analog circuitry and high-performance A/D and
D/A converters for near-zero, 0.5-ms latency. And while wefre on the subject,
note that you also get eight channels of USB output.
The intuitive user interface and
high-resolution LCD screen make it faster and more efficient than ever
before to create any mix youfre after. Further, with proprietary FPGA
technology at the heart of the mixerfs audio-signal processing, all channels are
handled in parallel, audio and control signals are completely isolated from one
another, and whatfs more, custom builds tailored to specific applications are
also supported. And as if this werenft enough, parallel processing also significantly
reduces the clock speed, all but eliminating the need for cooling and keeping
power consumption at a low 200 W. Meanwhile, the mixer can also be powered by
24 V DC. All in all, the M2820 Mixing Console packs a formidable array of
state-of-the-art technologies, providing everything required for a cutting-edge
Design Concept 1: Easy to use. For
the M2820, we wanted to liberate the sound engineer as much as possible from having
to remember or look up complicated operations and procedures. The conscious
decision-making required for such tasks is a left-brain activity, and it disrupts
the creative processes of the right brain. Like any good tool, the mixer must
feel like a natural extension of the body—something that the engineer can use
instinctively, without thinking, to realize the sound in his or her mindfs ear.
mixer is the central element of a highly complex yet subjective process where many
input signals are expertly mixed together, multiple mixed signals are output,
and highly personal adjustments are made based on the resulting sound. As such,
it relies on the fine-tuned sense of hearing of the engineer. And in order that
he or she may focus on creating the perfect mix as efficiently as possible, our
task was to minimize the number of actual operations required. To this end,
faders all correspond directly to input channels, information is presented in a
highly intuitive fashion for instinctive decision making, functions are
logically assigned to switches and buttons, and screens are arranged for
effortless navigation to the desired functions.
To be truly
intuitive—to free the engineer from the realm of conscious decisions—we knew
the M2820 would have to provide unfailing peace of mind, it would have to feel
like a natural extension of the body, and it must allow for extended use without
tiring. A key step in
achieving this goal was minimizing the number of operations and procedures
required to be remembered. And while human error can never be eliminated from
the mixing environment, we wanted to make sure that any mistakes could be easily
rectified. When the creative juices are in full flow, trying to recall each
step in a complex procedure jerks onefs train of thought from the right brain
into the left. This simply gets in the way of creating the perfect mix.
the streamlining of operations and screen layouts also allowed us to achieve
another usability goal—namely, ensuring that the M2820 could be quickly and
easily put to use by anyone, regardless of their level of experience. Beginners
and experts alike will find functions efficiently organized to suit their
advent of high-resolution smartphone cameras, anyone could take high-quality
photos wherever they may be, prompting a boom in the popularity of photography.
Here, high performance and convenience significantly lowered the barriers to
entry, which in turn has allowed new talent to blossom. Meanwhile, advances in
digital technologies have made the PC ubiquitous, and with so many regular
users, computer applications must allow complex tasks to be completed almost
without thinking about them. Ease of use is key, even to the extent that the
total number of mouse clicks must be minimized for optimum simplicity.
applies to the sound mixer. More than just a simple summer of audio signals, it
can rightly be called the main control panel of the music studio or live-music
venue. As a professional creative tool—not unlike SLR or TV cameras—it relies
heavily on the senses, making the operator much like a performing artist. The
starting line for any such device must be incredibly simple operation that
allows the sound designer to recreate in the real world what can already be
heard in his or her head.
Design Concept 2: Uninterruptible
processing of audio signals is hardwired into the M2820, and as long as the
power stays on, the sound will not cut out. Built using proprietary technology,
a dedicated FPGA processes signals on all audio channels in parallel, manipulating
this data using parameters as variables. Thus, when no changes made to the
parameters, audio signals will continue to flow through the system in accordance
with current settings. In this, we have realized a level of stability
equivalent to that of an analog desk.
states of faders, encoders, and switches are detected in a sequential fashion,
and the corresponding control data is written to specially designed registers
in the FPGA dedicated to audio-signal processing. The use of registers in this
way to transfer control data has made it possible to totally isolate control
signal processing and audio signal processing from one another. Meanwhile, a
separate CPU writes control data and monitors the operating status of the FPGA,
and using an array of microcontrollers, values are rapidly acquired from
faders, encoders, and switches. This also allows complete scenes to be easily
stored and recalled whenever needed.
processing on the M2820 is achieved using a DIMM-PC equipped with a GPU and
running Linux. High-speed rendering has been achieved through the development
of special GPU code.
field-programmable gate array (FPGA) is a type of integrated circuit that,
using software, can be freely configured by a designer after production, thereby
making it easy to build custom chips. Depending on the size of the chip needed,
the number of logic elements in an FPGA can vary widely, and similarly, prices can
range from several dollars to tens of thousands.
software is needed to create programs in the FPGA fabric, the resulting chip is
completely hardware—in other words, it does not need any software to operate. Calculations
occur as a matter of course when current flows through the chip, making it just
as reliable as an analog circuit.
Yet the FPGA approach
offers many more advantages: For a start, high-density integration provides for
smaller chips. In addition, a single FPGA chip will consume much less power
than a comparable circuit board, and it can be powered using batteries alone.
And if we consider that packaging accounts for roughly half the cost of circuit
assembly, it is clear that VLSI designs made possible by FPGA technology allow
for significant cost savings in terms of wiring, boards, wrapping, sockets,
connectors, and casings. Finally, VLSA chips are fast—much faster than circuits
assembled at the circuit-board level—and one of the reasons for this is the
dramatic reduction in distances between individual components.
As evidenced by our
development of a new method for parallel processing of audio signals in the M2820, the
FPGA approach offers great potential going forward. This is particularly true when we trust
Moore' Law and its assertions that (1) the number of logic elements in dense integrated circuits
will continue to grow, boosting stability and performance; and (2) greater LSI production volumes
will continue to pull down prices.
Design Concept 3: Stunning sound
The sounds we
hear are not pure tones—they also contain a rich mixture of overtones and
noise. And we do not hear them with our ears alone: our ear drums certainly
vibrate, but so too do other parts of the body. What all this means is that the
sensation of hearing is highly complex, and to faithfully capture these signal
in the digital realm, we need the highest possible sampling frequency.
At the heart
of audio-signal processing in the M2820 is a dedicated 192-kHz chip built using
proprietary FPGA technology. This phenomenal sampling frequency, combined with the
remarkable dynamic range afforded by the chipfs 40-bit architecture, delivers
performance that far surpasses analog devices and ensures that digital
processing is possible right down to the noise floor.
that the mixerfs sound quality is ultimately defined by its analog circuits and
analog-to-digital converters (ADC). With this in mind, we brought ATLfs tried
and trusted amplification circuits fully up to date for use in the M2820,
pairing them with the Asahi Kasei AK5397—an ADC boasting a signal-noise ratio
of 128 dB—in a 192-kHz, 32-bit configuration for stunning sound quality.
Design Concept 4: Support for 196-kHz,
32-bit multitrack recording
connected via USB to a PC, the M2820 can feed up to eight tracks of superior
quality audio to Pro Tools or any other digital audio workstation running on
it. This makes it incredibly easy to create high-resolution recordings and
typically combine samples from 16 or more input channels simultaneously, and
internal processors need a high bit depth in order to handle all of this data.
Summing 32 channels of 32-bit audio would require processing with a bit depth
of 37. However, the summing of samples can produce nonlinear results, and when
hundreds of these errors occur in a digital-to-analog converter, significant
distortion may be audible in the output. It is for this reason that we
developed the M2820fs audio-signal processor as a 40-bit system.
intuitive user interface
input channels: 28
output channels: 20
output channels: 8
rate: 192 kHz
separation of control and audio signals
analog circuitry combined with high-performance ADCs
chip used for all digital processing of audio signals
for custom builds