® 162SL Compressor/Limiter User Manual
IMPORTANT SAFETY INSTRUCTIONS WARNING FOR YOUR PROTECTION READ THE FOLLOWING: CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN A T T E N T I O N : RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR W A R N I N G : TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE The symbols shown above are internationally accepted symbols that warn of potential hazards with electrical products.
IMPORTANT SAFETY INSTRUCTIONS U.K. MAINS PLUG WARNING ELECTROMAGNETIC COMPATIBILITY This unit conforms to the Product Specifications noted on the Declaration of Conformity. Operation is subject to the following two conditions: • this device may not cause harmful interference, and • this device must accept any interference received, including interference that may cause undesired operation. Operation of this unit within significant electromagnetic fields should be avoided.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Why you need compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 The difference between compressors and limiters . . . . . . . . . . . . . . . . . . . . . .4 The compression and limiting effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Limiters and PeakStopPlus™ . . . . . . . . . . . . . . . . . . . . . . . . .
Why You Need A Compressor A remarkable feature of the human ear is that it can detect an extremely wide range of amplitude changes - from the slightest whisper to a deafening clap of thunder. If one tries to record or reproduce this wide spectrum of sound with the help of amplifiers, cassette recorders, records, or even digital recorders, one is immediately restricted by the physical limitations of electronic and acoustic sound reproduction technology.
Clipping Clipped signal heavily distorted Headroom Operating Level Dynamic Range Useable dynamic range Noise Floor Audio levels below here are not heard, because of noise i i The Difference Between Compressors and Limiters By measuring the dynamic range of musical instruments in live recording situations, you will experience extreme amplitudes which will often lead to overload in subsequent signal processing equipment.
The Compression and Limiting Effects On a compressor, there is a relationship between the input signal, and the threshold level, input, output, and ratio settings. Look at an input signal applied to the inputs of two compressors. The threshold level of the second unit is set ten decibels higher than the threshold of the first unit.
Furthermore, it is interesting to note that by comparing the input and output waveforms for the compressed mode, the quietest sections of the input signal have been effectively raised in level, whereas the loudest sections have been effectively decreased in level. The overall effect is that both ends of the dynamic range have been pushed toward the middle. This squashing effect of compression is important to remember and highlights the major difference between compressing and limiting.
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. Great care has gone into the design of the PeakStopPlus limiter to keep it acoustically transparent. Appropriate use of it can protect your gear while keeping the signal free of artifacts.
Connections The 162SL is connected for operation using the rear panel XLR or 1/4” connectors. Note that the two rear panel input sections have a push-switch which lifts the contact on pin #1 (ground). Keep this switch in the OFF position (pin #1 connected) until all connections are made. Be sure that your input and output cables are wired in the “pin 2/tip” configuration, which is printed on the rear panel of the 162SL.
Front Panel Controls OverEasy® Switch: This switch activates/deactivates the OverEasy® characteristics of the 162SL. When the switch is IN, the 162SL is in OVEREASY mode. OverEasy is a process which allows the user to compress a signal more gently than a hard knee compressor through the threshold region. This action produces a much smoother “natural-sounding” compression effect. When the OverEasy switch is OUT, the regular, hard knee action of the compressor is active.
increase in output level, regardless of how far the set threshold level is exceeded. This occurs in both OverEasy® and hard 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. Auto Switch: This switch sets the 162SL for automatic or manual operation.
PeakStopPlus® Switch and LED: The dynamics of the dbx 162SL are set to handle fast transients through PeakStop® limiting and the newer PeakStopPlus. PeakStop is the process first introduced on the dbx 165A compressor/limiter. PeakStop is made up of an extremely fast-reacting detector, called Instantaneous Transient Clamp. The sound of PeakStop became popular as the 165A permeated the audio industry, and quickly became the standard looked for by many top artists of the day.
Bypass Switch and LED: This switch activates a hard-wire relay bypass system, which allows the audio signal to pass through the compressor directly from input to output, even when the 162SL is turned off. That is to say that the XLR Pin 2 at the input connector is directly connected to the XLR Pin 2 at the output connector, and the XLR Pin 3 at the input connector is directly connected to the XLR Pin 3 at the output connector. When the 162SL is in bypass mode the LED directly above the Bypass switch is lit.
Note that the gain reduction scale is linear in dB as opposed to the standard VU markings on the upper scale on which input and output levels are monitored. This allows for easy visual indication of gain reduction, as it can be read in a fraction of a second, with only a fleeting glance from the engineer. I n pu t Meter Selection Switch and LED: Selecting this mode via the switch allows the user to monitor the incoming signal on the logarithmic (upper) scale of the VU meter.
PHONE: TIP RING SLEEVE POWER XLR: PIN 1 PIN 2 PIN 3 28 WATTS CHANNEL 2 OUTPUTS FUSE REPLACEMENT RATINGS 100V-120V T 400mA L 250V 220V-240V T 200mA L 250V SIDECHAIN RETURN INTPUTS CHANNEL 1 OUTPUTS GND +4 dBu SIDECHAIN RETURN SEND -10 dBV LIFT INTPUTS GND +4 dBu SEND -10 dBV LIFT Rear Panel Au dio Input and Output Connectors: Each audio input and output channel of the 162SL offers both 1/4” and XLR connectors.
OverEasy® And Hard Knee In a typical hard-knee compressor, the threshold control sets a reference level above which input signals will be attenuated in the manner defined by the setting of the Compression ratio control. Input signals which fall below this level will pass through unprocessed.
Using The Stereo Couple Switch Two channels of program material do not necessarily constitute a stereo program. A stereo program is one where the two channels are recorded and/or mixed to create the illusion of a single unified panorama of sound. The stability of the psychoacoustic image of each sound source within the stereo spectrum depends upon its ability to maintain a specific phase and amplitude relationship from the left to the right channel.
trols. This faster attack time allows the transients to by captured and compressed without overshoot and allows a quick release from compression without “punching holes” in the sound. There is no right way to set the Attack and Release controls.
While PeakStopPlus™ is typically used as a protective function, creative effects can be achieved by intentionally driving the signal into heavy PeakStopPlus™ limiting. Great care has gone into the design of the PeakStopPlus™ limiter to keep it acoustically transparent. Appropriate use of it can protect your gear while keeping the signal free of artifacts.
tions. 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 162SL 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 162SL is driven into heavy gain reduction.
not cause compression, and the program is not subject to the phase shift normally caused by program equalization. During the recording of cymbals and tom-toms, a compressor with an equalizer in the sidechain path can help prevent tape saturation. The equalizer can be adjusted for boost with a peak of about 5kHz, causing the cymbal to be compressed on a very loud crash, stopping tape saturation at high frequencies, where there is less headroom.
Anticipated Compression By feeding the program directly to the 162SL's sidechain return and sending the audio signal through a delay line before the audio input, the unit can anticipate the need for a gain change. See diagram on the following page. With some experimentation, the effect can be that of zero attack time at a given frequency.
Technical Support If you require technical support, contact dbx Customer Service. Be prepared to accurately describe the problem. Know the serial number of your unit - this is printed on a sticker attached to the rear panel. If you have not already taken the time to fill out your warranty registration card and send it in, please do so now. Factory Service Before you return a product to the factory for service, we recommend you refer to the manual.
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INPUTS Connectors: Type: Impedance: Maximum Input Level: CMRR: Female XLR and 1/4” TRS (Pin 2 and Tip hot) Electronically balanced/unbalanced, RF filtered. Balanced > 50 kΩ, unbalanced > 25 kΩ. >+24dBu balanced and unbalanced. >40dB; typically > 55dB at 1kHz OUTPUTS Connectors: Type: Impedance: Maximum Output Level: Male XLR and 1/4” TRS (Pin 2 and Tip hot) Transformer balanced/unbalanced, RF filtered. Balanced 30Ω, unbalanced 15Ω. >+24dBu, >+22dBm(into 600Ω Load).
FUNCTION SWITCHES Sidechain: OverEasy®: Auto: PeakStopPlus®: Bypass: Input: Output: GR: Pin 1 Lift (Rear Panel) Routes external sidechain input signal to the detector. Activates the OverEasy‚ compression function. Activates automatic program-dependent attack and release times, disabling the manual attack and release controls. Activates the Intelligent Predictive Limiting® (Stage 2) section of the limiter. Activates the direct input-to-output hard-wire relay bypass.
® 8760 South Sandy Pkwy. Sandy, Utah 84070 Phone: (801) 568-7660 Fax: (801) 568-7662 Questions or comments? E•mail us at: customer@dbxpro.com or visit our World Wide Web home page at: www.dbxpro.
