Continuing the audio
effects series, again, we all know of audio effects and what they generally are
supposed to do. They are used to manipulate audio in ways that are not available
with traditional playing and recording techniques. If you're
like me, and enjoy dabbling in audio production, you're
probably familiar with all the basic effects and maybe some other types. Noise
gate will be one of the topics of discussion today. Noise gate, what the heck is
that? If that was your first reaction, you're not
alone. Please don't worry; we will be demystifying
this subject later on in the article. We will also be discussing flange, which
is a more standard and widely used audio effect. So, in todays article we will
be discussing both noise gate and flange effects, how they work and why they
work the way they do.
Noise Gate
Basically, noise gate is a device or
software logic that is used to manage the
volume of an audio signal, in recording
studios and in sound reinforcement. They are
also used by musicians, in a portable form,
to control amplification noise. At its most
simple form it controls noise by only
allowing sound to pass through it at a
certain set threshold. Think of it as a
literal gate; when the gate is open sound
can pass, when the gate is closed no signal
is allowed through. More robust noise gate
units have extra controls, I.E. attack,
sustain, decay, release. This is so that you
can further control the gating of your
audio. Say you'd
like to have the gate applied in a hard
fashion, you would set a short attack and a
short release, so on and so forth. Noise
gates are often used to isolate background
noise from live recordings in order to
eliminate them from the final copy.
Flange
Flange is related to the phasing effect
produced by a, well, phaser effects unit. It
is produced when two identical signals are
mixed together, with one of the signals
time-delayed by a small and gradually
changing amount. The amount is usually equal
to or less than 20 milliseconds. Peaks and
notches are produced in the combined
frequency spectrum, related in a linear
harmonic series. Part of the output signal
is fed back in and resonates, intensifying
the peaks and notches. This effect was
originally generated with 3 three headed
tape machines. Two of the tape machines
would play the signal, obviously somewhat
out of synch, and the third tape machine
would record the output. The modern version
of the effect is created using DSP (digital
signal processing) technology.
This is the
second part in my continuing series on audio
effects. Today we discussed noise gate and
flange, we'll be
moving on some more advanced effects later
on. I hope that this helped you all
understand the basic functionality of these
two effects, ultimately making your next
foray into audio editing a bit less
intimidating.