10
USB 7706
Compressor Dual Channel
3.2 The COMPRESSOR As A Sound Effects Unit
Since the early 1960 s, musicians have been looking at the recording process as a way to create new sounds. With respect
to compressors, the pumping effect (which had been avoided by earlier recording engineers) suddenly became fashiona-
ble and was often utilized as creative tool, laying the groundwork for many of the sounds now considered indispensable in
contemporary music. The compressor can used in this role because you can hear it working, and, in this instance, control
of the dynamic range is of secondary importance.
The COMPRESSOR, with its extensive range of functions, is well suited to this application. Useful sound effects of this kind
can be achieved using "extreme" settings. To achieve this, set the THRESHOLD control to a fairly low level, the RATIO con-
trol to almost maximum and use the ATTACK and RELEASE controls to obtain the desire effect.
To get the most out of your unit, experiment with all the controls in order to get a feel of their function!
4. LIMITER FUNCTION
In addition to providing a variety of ways to compress signals, the COMPRESSOR can also be used to limit the overall out-
put level of the unit and to protect subsequent units from signal peaks, short term overloading and over modulation (trans-
mitters etc.).
4.1 Initial Settings For The Limiter Function
Controls:
Settings
THRESHOLD control:
+20 dBu
RATIO control:
∞
ATTACK control:
0.1msec.
AUTO switch:
Manual (out)
RELEASE control:
0.3 sec.
OUTPUT control:
0 dB
IN/OUT switch:
IN (depressed)
Rotate the compressor's THRESHOLD control counterclockwise until an appropriate amount of gain reduction is indicated
on the GAIN REDUCTION meter. As necessary, the attack and release times can be modified manually.
(Note: Too short attack times can lead to distortion and too long times let dangerous transients pass the unit unhindered.
The RELEASE control should be adjusted to avoid side effects as "fluttering" and "pumping" of the processed signal.)
SPECIAL APPLICATIONS
1. USING THE COMPRESSOR FOR RECORDING AND CASSETTE DUPLICATION
In the recording and duplication field, the goal should always be to achieve an optimum recording level onto the recording
media. Too low or too high recording levels lead to side effects such as noise, distortion, etc. In mastering and multi-track
recording, as well as in duplication, one should always take care to utilize the full dynamic range of the tape recorder, DAT
recorder etc. In principal, it is possible to control the recording level by "riding" faders, which means that the gain is inc-
reased with low-level signals, and reduced for high-level signals. It is obvious that this method is insufficient, especially in
live recordings, because the expected signal levels cannot be anticipated correctly. Furthermore during multi-track recor-
dings, which are run under hectic circumstances, the signal level of all channels cannot be monitored and controlled at the
same time. Generally, it is not possible to achieve satisfying recording results using manual control in this way.
An automatic gain control system achieves better and more constant results. Use the COMPRESSOR by starting with the
initial settings, and use its dynamic control functions to drive, either an analog, or digital recording noise and distortion free
up to the limit of its maximum dynamic range.
1.1 The COMPRESSOR In Digital Recording and Sampling
During analog recording, too-low recording levels lead to an increased noise level, whereas too high levels will cause a com-
pressed and "squashed" sound. In extreme cases, loud levels will cause distortion due to tape saturation. In contrast to
analog, side effects in digital recording always become extremely audible: with decreasing levels a tape loses resolution
and the recording sounds "hard" and loses "atmosphere" . "With excessive level, the recording sounds harsh and heavily
distorted. In order to avoid these effects, the limiter function of the compressor should be used. With proper limiting, a digi-
tal recording or sampling can be optimally set to optimum levels without any problem.
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