User Guide / Owners Manual

ARTURIA – VOX Continental V – USER MANUAL 11
This idea has been around for a long time, but development has been hindered
until recently because processors that were powerful enough to handle the
computational complexity of the physical models either didn’t exist or were too
expensive.
But if you’ve been watching the technological trajectories, you know those days
are in the past. And we’re just as happy about that as you are.
1.2.2 A computational conundrum
Here’s an example of what must be taken into account while developing a
physical model. To recreate the sound of a drum, for instance, a formula must be
in place to represent all of the ways the collision between a drum stick and a drum
head sends shockwaves through a two-dimensional membrane. Among other
things, the formula must incorporate:
 The properties of the striker: its rigidity, the velocity of the hit, the material,
and how/where the strike happens
 The membrane: its mass density, elasticity, woven fabric vs. plastic vs. skin,
etc.
 The sympathetic resonances of the membrane and the body of the drum
 The conditions at the membrane boundaries: is there a rigid termination to
the drum´s body, or are there multiple, independently adjustable pressure
points?
 The ancillary and perhaps lingering response of additional components,
such as the snares under a snare drum.
Similar complexities can be found in instruments such as an acoustic guitar. A few
years ago, a French scientist finally completed a comprehensive modeling of all
acoustic guitar parameters. The calculations to produce the sound took three
days!
The second-biggest challenge of physical modeling synthesis is to simplify the
algorithms wherever possible without sacrificing the essential nature of the
instrument being modeled. The goal is to achieve an efficient model which can be
used interactively, in real time, without limiting the spontaneous paths a musician
may take during a rush of creativity.
1.2.3 The endless revolution
There are several methods of physical modeling synthesis, including Karplus-Strong
algorithms, digital waveguide synthesis, and formant synthesis. Each one uses a
different paradigm to bring a modeled sound to its musical fruition.
The salient point here is that physical modeling synthesis is capable of recreating
the character of a “real” instrument during performance, including its subtle
nuances of expression, while using a thousand times less hard drive space than the
“sampling” method would take to produce an inferior result.