User Manual

RackPack: DynaMaxx

This section deals with the technical background of the Dy n a Ma x x 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 ben-

efits of the Dy n a Ma x x 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 choosing 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 mostly fixed and they

tend to play a minor role. The inappropriate choice of time constants

is mainly responsible for the familiar pumping or breathing effects.

Threshold and Ratio are easier to set up, but when high compression

ratios are used, high frequencies tend to become over-compressed,

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 parameters are optimized for this

moment in time only. The rest of the time, the time constants are less

than optimal. Taking into consideration that each musical instrument

has varying attack and release times, depending not only on the char-

acter of the instrument, 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.

Setting up a conventional compressor perfectly for recording a vocal

part is nearly impossible. However, perfect gain control is extremely

important with digital systems to make the best possible use of the

available digital headroom while preventing clipping. Vocals can have

an extremely wide dynamic range, so for the best results, it may be-

come necessary to re-adjust the compressor settings while recording.

The DynaMaxx solves these problems by the use of intelligent automa-

tion. It 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 techno-

logy maintains signal clarity, even at high levels of compression.

Technology And Applications