Akai EWI 4000m Electric Wind Instrument Akai EWI 4000m Electric ...

VI feature
Fig. 2: Frequency Modulation (FM) is a type of synthesis (popularized by
Yamaha’s DX series) in which one wave (a modulator) is fed into another (a carrier)
to generate a timbre that is harmonically rich. When the modulator and carrier
are sine waves, the harmonics produced are predictable. In Synth1, the output of
OSC2 is the modulator, and the carrier is OSC1. Since both of these oscillators are
using complex waveforms in the Clave patch, the resulting timbre produced when
using FM comprises hundreds of frequenciesæwhich, due to their number and
amplitude, are a form of noise. Try raising and lowering the FM amount to hear
the effect on the “noise” portion of the Clave patch.
pretty easy; making a knock-you-over-dead
clap is a multi-step process.
We’ve programmed two claps. Program
49, Small Handclap, relies almost exclusively
on basic filter and envelope settings to create
the core sound. A highpass filter is used to
nail the timbre, which if you listen closely has
many of the spectral characteristics of the hihats
we constructed last time around.
To see for yourself the dramatic effect a filter
has on a sound, toggle through the other
available modes. Once you leave HP12 (the
highpass filter) our clap becomes lifeless and
sounds more like an unwelcome stranger
knocking at our door.
Now go back to HP12 and enable Tempo
Delay. Our settings double the sound and
spread it across the stereo spectrum. Next,
enable Chorus/Flange, which thickens the
sound. For fun you can enable Effect A.D.1,
which gives you an interesting percussive
sound, but out of the realm of the clap.
Now Select Program 50, Big Handclap.
This is essentially the same program as Small
Handclap, but when we enabled Effect A.D.1,
we changed the filter to BP12 (bandpass).
Doing that allowed us to retain the basic clap
soundæby cutting out much of the high frequency
content we heard in the A.D.1 experiment
in the previous paragraphæwhile at the
same time thickening the sound considerably.
Deep into the (Rain) forest
While a completely different type of instrument
from the hi-hat?and certainly not metallic
in any way?the decidedly primitive rain-
18 VIRTUAL INSTRUMENTS
stick has a sound
that contains a number
of the same
spectral components.
The primary
difference between
it and a hi-hat is in
the shape of the
envelopes (both filter
and amplitude).
So even though the
rainstick is about as
organic an instrument
as one can
imagine, the bits
and bytes of our virtual
analog synthesizer
can do a very
convincing job of
emulating it.
Let’s start by calling
up Program 51,
Medium Hi-Hat. This
provides our basic
timbre. (For those of
you not using
Synth1, our example
Medium Hi-Hat
sound is created
using noise
processed through a
high pass filter with
a bit of resonance
added to give it a metallic edge. The filter
envelope is used to fine tune the timbre, but
the amplitude envelope provides the majority
of the hat’s “sharp hit” characteristic.)
We now need to tweak the envelopes to
eliminate the hi-hat’s sharp attack and create
the trademark rainstick sound of “grains”
(rice, small pebbles, etc.) falling through the
hollow stick. Start by increasing the amplifier’s
Attack time to a bit more than halfway-up.
Play and hold a note. Notice how this simple
adjustment has a dramatic effect on the
sound, and has taken us quite far toward the
rainstick emulation.
Now we’ll adjust the Amplifier Decay
timeæincreasing it to about three-fourths of
its throwæto create the long, smooth sound
of the grains continuing their journey through
the stick.
Okay. We’re pretty close to the basic shape
of the sound, but it’s not definitively a rainstick.
To go that extra mile, we’ll need to
enlist a number of other parameters.
Call up Program 52, Rainstick, and play a
note. You’ll notice that the sound is now
much more refined timbrally (it’s not just
pouring rain anymoreæwe can hear the individual
“droplets”). We’ve done this by making
some minor changes to the filter envelope,
but more significantly we’ve enlisted the aid
of the LFOs.
LFO1 is set to a noise (random) waveform
with its output routed to the filter, causing
the filter cutoff point to change rapidly over
the course of a held note. This rapid randomization
of the frequency content helps to dis-
tinguish the “droplets’ ” individuality. LFO2
uses a high-speed random sine wave assigned
to amplitude, which further serves to define
individual droplets. Finally we adjust the FRQ,
RES, and SAT controls for the desired tonal
coloration.
Uh-oh…bad weather ahead
Mother Nature is pretty good at creating
impressive noises, and it just so happens that
two of the most common?lightning strikes and
thunder?are comprised of ingredients readily
available on basic analog subtractive synthesizers.
If you’ve been following this series, you
know that we always break down sounds into
basic components, i.e. their core tonality
(waveform), harmonic content (filter), and
amplitude (VCA, or Voltage Controlled
Amplifier), and then apply various voltages
from modulation sources, such as envelopes
and LFOs, to manipulate the core ingredients.
So with those basic principles in mind, let’s don
our raincoats and call in the thunderclouds.
A lightning strike usually consists of a sharp
crack, followed by thunder. The particular
incarnation we created here (Program 53) has
the lightning striking right on top of us. In
other words, the thunder happens simultaneously
with the initial strike.
The lightning sound starts with OSC2 set
to noise, and the filter parameters set to create
a medium length “crack.” (You should
experiment with the filter envelope values to
see how they affect the sound. Hint: Decay
and Sustain are critical.) Synth1’s filter SAT
parameter has been used to fatten the crack.
LP12 is the filter selection, since it allows both
a great amount of high frequency content to
pass through for the initial crack, while at the
same time providing enough filtering for us
to create the rumbling thunder that follows.
Now check the settings of the Amplitude
(CONTINUED ON PAGE 62)
Downloading and
installing Synth1
and the example
patches
As with our past articles, we’re using
the freeware Synth1 for our examples.
Instructions for downloading and
installing Synth1 can be found at More
Online at
www.virtualinstrumentsmag.com. There
you’ll also find the Synth1 patch examples
used in this article, as well as those
used in our last three installments. You
can use the synth of your choice, since
the controls we refer to are common to
virtually all software synths (at least
those of the analog subtractive variety).