DL441 OPERATORS’ MANUAL
7
OPERATION
The unit should be connected in-line with the signal to be processed via suitable
insert points. Ensure that the insert send and return level on your console matches
the operating level set up using the rear panel push-buttons on the DL441. If not,
select the appropriate operating level on the DL441.
For mono use, each channel may be considered as being completely independent
and set up accordingly. For use with stereo signals such as complete mixes or
submixes, the appropriate pair of channels should be switched to Stereo Link mode
and all setting up done using the left hand channel(s) controls.
Setting up is simplified by the auto attack and release system which continually
optimises the attack and release times to suit the dynamics of the material being
processed. The ratio setting depends on how firmly the signal dynamics need
controlling; as a rule, higher ratios provide a higher degree of control but also tend to
be more audibly apparent in operation when high levels of gain reduction are
required. In general, a higher compression ratio may be used when in Soft Knee
mode without compromising the subjective sound quality.
Having selected Hard or Soft Knee and set a suitable Ratio, setting up is simply a
matter of adjusting the Threshold control until the desired amount of gain reduction
occurs. This is judged partly by ear and partly by observing the gain reduction meter.
Normally a maximum gain reduction of between 8dB and 12dB will be adequate. If
more gain reduction appears necessary, it is worth considering applying a
conservative degree of compression during recording and then further compression
while mixing.
Compressing during a mix does increase the subjective level of tape and other
background noises during pauses and quiet passages as maximum gain is applied
when the signal level is minimum. For this reason, it is unwise to use more
compression than is strictly necessary.
Finally, the Gain control may be set to provide the required output level using the
level meter as a guide. Avoid running at very high output levels as this reduces the
available amount of signal headroom and could lead to distortion in extreme cases.
Once the gain is correct, the Peak limiter Level control should be adjusted so that the
limiter LED only lights briefly on extreme signal peaks. Alternatively, the Peak limiter
Level may first be set to the desired value and then the compressor Gain control
adjusted to ensure minimum limiter activity.
The Peak limiter has no bypass control, but turning the Level control fully clockwise
will effectively prevent the limiter from operating.
Compressors are often accused of dulling the sound being processed, but the auto
circuitry in the DL441 has been designed to allow transient sounds to pass through
cleanly, thus maintaining the clarity and transparency of the original source. Soft
Knee operation is usually preferable when unobtrusive gain control is required.
