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Divide and Conquer
Working with audio in the digital
world of computers has some great advantages over
traditional analogue systems -like inexpensive automation,
instant recall, and flexibility. Yet, the single
greatest limitation of DAW based studios is the
system resources of the computer itself. Once the
system resources are taped your tracks can come
to a grinding halt. Modern digital audio workstations
rely on CPU power, RAM, bus speed, and hard disk
speed for not only editing and recording multiple
tracks of audio but also processing audio in real
time via plug-ins, while at the same time using
the computer as a synth/sampler instrument. This
multifunctional use can quickly drain even today's
most powerful computers -but what if you could divvy
up processing tasks -dedicating multiple computers
under the control of one master DAW program would
allow for one computer to handle virtual instruments,
another to handle plug-ins, and one master computer
to rule them all.
One
Ring to Rule Them All
Currently, there are a couple
of technologies dedicated to networking multiple
computers into one Super-DAW. Let's look at the
theory behind how this technology is made possible:
VST
System Link
VST System Link was developed
by Steinberg and allows for cross communication
between both Mac's and PC's equipped with ASIO 2.0
sound cards and a Steinberg host application like
Nuendo or Cubase SX/SL.
VST System Link utilizes the
actual digital audio stream from an AES, S/PDIF,
ADAT, or TDIF 24bit signal. The LSB, or Least Significant
Bit, of the audio stream serves "as a carrier
for transport and sample-accuracy synchronization
information ". Steinberg claims the system
allows for "no latency in mixing virtual instruments",
as well as no timing fluctuations.
This system allows for daisy
chaining multiple computers, all running a host
application, and each computer can take on certain
tasks. For instance, one computer could handle VST
instruments, while another handle VST plug-ins,
and all audio could be mixed with the host application
running on the "master" computer. One
nice feature of VST System Link is that computers
can be added or subtracted from the system without
having to reboot -in other words it's "hot
swappable".
One inherent drawback of VST
System Link is that you need a "host" application
running on every computer in the network. This means
that if you want three different computers on your
network you will need to pay for three software
package license's -this could become rather costly
for the general home or project studio owner. Of
course, this also allows for you to run Nuendo for
your main mixing/editing environment and then a
version of Cubase on a different machine for the
MIDI and virtual instruments -sounds like a very
powerful setup.
FX
Teleport
FX Teleport works on a different
principal than VST System link in that it uses one
computer as the master and only needs one "host" program.
The other networked computers run FX Teleport software
that communicates with a VST wrapper on the host
machine allowing for the signal to be sent to a
separate computer on the network -processed through
a plug-in, or as a virtual instrument- and then
sent back to the host program and computer.
This, of course, raises the
question of latency and jitter. Jitter is supposed
to be non-existent due to the buffer inherent in
the VST wrapper. Latency is said to exist on a minimal
level (6-9 ms). FX Teleport deals with the latency
issue by calculating and displaying the latency
of the system and then allowing you to set an offset
time to "end up with sample accurate synchronization
between your host machine and teleported FX".
This sounds like an ingenious way to delegate certain
DSP tasks to certain computers while only running
one version of a host program.
A great feature of the FX Teleport
is that the overall project file with automation
and virtual instrument information is still kept
in the original project on the host computer. In
fact, if one of the networked machines is down or
not available FX teleport will still try to launch
the associated plug-ins or virtual instruments with
the resources of the host computer.
One thing to keep in mind
with FX Teleport is that the capabilities will
be dependent on the standard networking features
of your PC operating system as well as your networking
hardware. Also, while VST System Link software
is free in supported versions on Steinberg's software
you'll have to pay separately for FX Teleport.
Of course, the software and ability to run 4 servers
or more cost only $199 -not a bad deal at all.
The Missing Link
I get excited thinking
about some of the implications networking solutions
like VST System Link and FX Teleport could have
for musicians today. Outside of allowing us to
divide up and dedicate certain resources to certain
computers it can also allow for freedom in working
with multiple musicians. For instance, someone
could be tweaking plug-in parameters while another
works with virtual instruments, all while someone
could be mixing and editing on the fly, and each
person could be doing this from their own computer
station. Now that would be cool.
Another Consideration
Parceling out the DSP
tasks to multiple computers is an excellent idea
-but not all of us (myself included) have more
than one computer, or the means to buy another
computer just for "dedicated processing".
With this in mind, another ingenious method of
squeezing out CPU resources has developed and
is found in programs like Emagic's Logic and MAGIX
Samplitude -the Freeze function.
The Freeze function takes the "less
is more" approach to dealing with conserving
CPU resources. Instead of sending signals out to
other dedicated computers the Freeze function condenses
CPU intensive tracks inside the computer. In other
words, you select the tracks that are bogging down
your system and the Freeze function will "reduce
their CPU-load down to the very minimal demand of
an unprocessed stereo audio track Ð thus freeing-up
potentially very large amounts of CPU-power which
can be used for other purposes".
This goes beyond simply
bouncing tracks in that the process is very fast,
and you can quickly get back to the original tracks
for further editing and tweaking. My guess is
that this type of function will start to become
common in all the major DAW programs out there
in the near future. Until then, whether you have
one computer, or a whole network of computers
dedicated to your studio, these emerging technologies
could possibly help you squeeze the most productivity
out of your rig.
Questions about
this or related topics? Write to doug@audiomidi.com.
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