Harman dbx 160SL - Automatic and Manual Timing; Peak Limiting Control

9
160S
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knee operation. Note that when a compressor is set to a compression ratio of 10:1 or more, it may be
considered to be LIMITING the input signal, especially when a fast attack time is selected.
Aut o Switch: This switch sets the 160SL for automatic or manual operation. When the Auto switch is IN
(autO mode), the compressor automatically adjusts its attack rate and release time to suit the program
envelope. (This autO mode sets the compressor for the same attack and release characteristics as dbx
Models 160, 161, 162, 163 and 164 compressor/limiters.) When the Auto switch is OUT (manual mode),
the front panel Attack and Release rate controls determine the maximum rate of gain change and the
behavior of the level detector circuitry.
In
autO mode, the 160SL utilizes the patented dbx RMS level detector with its program-dependent attack/
release characteristics to obtain natural-sounding compression or limiting. For special effects and certain
signal situations, however, it is often desirable to set fixed attack and release characteristics. manual
mode affords this capability. The autO mode is recommended for vocals as well as instruments. Because
the autO mode has a program dependent variable attack rate, the compressor may compress or limit
some program material smoother than in the manual mode which has a fixed attack characteristic. This
is especially true on vocals.
Att ack and Release Controls: Attack time is defined as the time taken for a compressor to respond
to program levels which have exceeded the threshold point. For the 160SL, this control ranges from
400dB/mS (extremely fast) to 1dB/mS. Release time is the amount of time a compressor takes to return
the program level to its original level, after the last excursion over the threshold point. The 160SL’s
release times range from 4000dB/second (very fast release time), to 10dB/second (slow release time).
A very fast attack setting (control maximum counterclockwise) will cause the compressor to act like a
peak limiter even though RMS detection circuitry is used. Slower attack settings cause the compressor
to act like an RMS or averaging detecting compressor/limiter. To achieve inaudible compression, it is
advisable to work with program dependent attack and release times (autO mode). The advantage of
program dependent compression is most apparent when processing musical material that is varied. For
compression, longer attack and release times are generally the best in order to keep the overall output
signal within a specified dynamic range. For limiting applications, considerably shorter attack and release
times are necessary to control fast transient signals or to increase headroom.
Sto p Level Control: This control adjusts the maximum peak output level of the 160SL regardless of any
other control. The PeakStop limiter comes after the compression and all other circuitry, except the
output gain; this provides for an absolute peak limit to be put on the peak excursions at the output via
the Instantaneous Transient Clamp
™
. Since the PeakStopPlus
™
limiter is a fail-safe limiter it must come after
the Output Gain control. If the output gain is set too high as compared to the PeakStopPlus
™
Level control,
continuous limiting can occur. While PeakStopPlus is typically used as a protective function, creative effects can be
achieved by intentionally driving the signal into heavy PeakStopPlus
™
limiting. Like the range of the Threshold
control, the scale of the Stop Level control is measured in dBu. The control ranges from +4dBu, all the
way to “OFF” (+30dBu). The top end of the scale is marked “OFF” because its internal setting, +30dBu,
is the actual maximum output level of the 160SL, and therefore signal passing through the unit will
pass untouched, up to the maximum output level of the 160SL. Because of this, the limiter is effectively
rendered “inactive” in the OFF setting.
160SL
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160SL
160SL
160SL
controls
controls
160SL
notes notes
160SL
160SL
160SL
Operations
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
160SL
Operations
Inspection Inspection
Operating
Operating
Operating Operating
Connection
Connection
Installation
Installation
Technical
Technical
Introduction Introduction
to your system
to your system
considerations
considerations
contents
contents
concept
concept
diagram
diagram
applications
applications
support and factory service
support and factory service
160SL
Specifications
Specifications
160SL
160SL
160SL
160SL
160SL
160SL
Manual
Manual
Design
Design
Block
Block
Controls
Controls
Advanced
Advanced
Warranty
Warranty
lue
series
b