DynaMaxx
7
What are compressors doing?
A brief description of the
well-known problems with
standard compressors
Static or fixed time constants
are responsible for the nega-
tive side-effects. Music is not
static and the attack and
release parameters of instru-
ments or vocals change
throughout a song.
D
YNA
M
AXX
ingeniously adapts
the time constants to the
music and generates better
compression set-ups than
standard compressors.
This section deals with the technical background of the
D
YNA
M
AXX
and explains why we felt it necessary to do some things
rather differently to the way other manufacturers do them. We
will also explain the benefits of the D
YNA
M
AXX
design.
Generally, the function of an audio compressor is to compress
the dynamic range of the source signal by altering the gain of its
signal path in response to the relative level of the signal as
compared to an arbitrary threshold level. In effect, this process
can be thought of as providing additional gain to low-level
signals or reducing gain in the presence of high-level signals.
Why are conventional compressors unsatisfactory?
One of the main difficulties in setting up a compressor is choo-
sing the time constants Attack, Decay, Sustain, and Release (in
short: ADSR). The most important time constants are Attack and
Release – in the context of gain control, Decay and Sustain are
generally fixed and in any event, they tend to play a minor role.
The inappropriate choice of time constants is mainly responsible
for the familiar pumping or breathing effects, though this effects
may be deliberately sought for creative applications. Unless the
attack time is set to be very short, fast transient attacks may get
through the system, because the compressor response is too slow
to bring them under control.
Threshold and Ratio are easier to set up, but when high
compression ratios are used, high frequencies tend to become
overcompressed, which makes the material sound dull or lacking
in presence. It is normal to set up compressors based on the
loudest peak in the program material, in which case the parame-
ters are optimised for this moment in time only. The rest of the
time, the time constants are less than optimal. Taking into consi-
deration that each musical instrument has varying attack and
release times, depending not only on the character of the instru-
ment, but also on the way it is played, you can see that it is almost
impossible to choose a set of fixed parameters that will be correct
for an entire piece of music.
In modern music productions, vocals are often recorded directly
to a digital format, which means that gain control is very impor-
tant due to digital systems’ inability to tolerate excessive levels. It
is extremely important to compress or limit the vocal part during
recording so as to make the best possible use of the available
digital headroom while preventing digital clipping. Vocals can
have an extremely wide dynamic range, especially in the case of
untrained pop singers, so for the best results, it may become
necessary to re-adjust the compressor settings while recording.
The D
YNA
M
AXX
solves these problems by the use of intelligent
automation – the compressor’s time constants are re-adjusted
adaptively in response to the changing dynamic characteristics of
the music. In other words, D
YNA
M
AXX
intelligently optimizes Attack
and Release times on the fly, which is why the control system is so
simple. Both Threshold and Ratio are combined within the
COMPRESS-control, and the advanced Double VCA Drive
TM
Techno-
logy maintains signal clarity, even at high levels of compression.
Tech Talk
