dbx 160SL - Manual (Page 23)

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160S
lue
series
b
160S
160S
160S
controls controls
160S
notes notes
160S
160S
160S
Operations
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
160S
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
160S
Specifications
Specifications
160S
160S
160S
160S
160S
160S
Manual
Manual
Design
Design
Block
Block
Controls
Controls
Advanced
Advanced
Warranty
Warranty
lue
series
b
160SL
lue
series
b
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
Specific Applications
Smoothing out variations in microphone levels
When the distance between a vocalist and a mic changes, variations in signal level occur. To smooth out these
variations, start with the 160SL adjusted for a low compression ratio (e.g., 4:1) and adjust the Threshold control
for optimum results, then increase the compression ratio if necessary. Due to the gentle OverEasy characteristic
available on the 160SL allows even fairly high ratios to be handled transparently.
Smoothing out variations in musical instrument levels
To achieve a smoother electric bass sound, compress the instrument’s output with a ratio of about 4:1 (the
Compression ratio control set at approximately 12:00). Compression lessens the loudness variations among the
strings and increases the sustain. Other instruments, such as horns, vary in loudness depending on the note being
played, and benefit similarly.
Note: When compressing a stereo program with the 160SL, the factors affecting a compression curve and the actual compression ratio and threshold set-
tings are like those previously covered with reference to single channels of program material. However, it will generally be found that large amounts
of compression are more audible in a mixed stereo program than they might be on the separate tracks that were mixed to create the program.
Raising a signal out of a mix
Since reducing dynamic range increases the average signal level by a small amount, a single track can be raised
out of a mix by boosting its level slightly and applying compression. It is also possible to separate certain vocals
or instruments from a mono program already mixed by frequency-weighted compression.
Using your EQ to reduce feedback in live settings
You can use your 160SL and an EQ (a dbx 20 or 30 Series graphic EQ) to reduce feedback in clubs or halls by
placing the 160SL at ∞:1, hard knee, and a low threshold. Increase the output gain until the first feedback ring
occurs. The 160SL will catch it, and hold it as a constant tone so you can adjust your EQ to minimize it. Continue
to increase your console gain and set your EQ until the first 3 or 4
ring frequencies have been compensated for.
Preventing tape saturation
With programs of widely varying levels, compression can prevent recording levels from saturating tape tracks.
Speaker protection
Compressors are frequently used to prevent excessive program levels from damaging drivers in a sound-reinforce-
ment system. Limiting also benefits intelligibility by allowing low-level input signals to be reproduced through the
system at higher volume. In a musical performance, this provides additional intimacy as the vocalist’s whispers
are heard clearly at every seat in the house. The OverEasy curve available with the 160SL permits a very high
amount of compression (10:1 or greater) to be used in many situations. Vocalists and musicians don’t get the
sense of being held back, but high average levels can be maintained without speaker damage due to excessive
heat buildup.
In circumstances where the 160SL is expected to cause no change in gain unless an emergency arises (wildly
excessive levels), some operators set the compression ratio to ∞:1, the threshold to the highest permissible level,
and set the stop level so that it just barely cuts in when the 160SL is driven into heavy gain reduction. As a general
rule, the compressors should be as close to the amplifiers as possible in the signal chain. If the 160SL is placed
before the EQ, for example, a potentially damaging boost in EQ won’t be seen by the 160SL and the speakers may
be damaged. For maximum sound pressure levels, large sound reinforcement systems frequently use a separate
compressor on each output of the electronic crossover(s). For a stereo sound-reinforcement system, stereo linked
160Ss should be used on each band (low-low, mid-mid, etc.).