6
OPERATION MANUAL
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The dbx 20 Series Graphic Equalizers are useful audio signal processing tools in situations where precise frequency
control is required across the audible frequency spectrum.
When used with an audio spectrum analyzer the EQs can tune any acoustical environment -- from the studio to the
concert hall -- to stop ringing, increase clarity, and flatten the overall frequency response of the environment. A
real-time spectrum analyzer or other types of audio environment analyzers are very useful in determining the
amount of equalization needed.
Insert the graphic equalizer between the signal source (usually a mixer) and the power amplifiers (or the crossover if
there is one). Adjust the level and equalization as required to yield the desired system response. The long throw fad
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ers of the EQs allow very precise settings of the equalization for accurate equalization curves.
For optimum signal-to-noise response, the gain structure of the sound system must be properly set up. Each compo
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nent of the sound system should be set at its nominal operating level, starting with the first element in the system,
usually a mixing console. Each element should be run at its nominal operating level in order to take advantage of
the maximum signal-to-noise properties of that element. Loudspeaker amplifiers, as the last element in the chain,
should be set only as loud as necessary, in order to avoid inducing unnecessary noise into the system.
All active equalizers, by nature of design, add noise when boosting or cutting that can easily degrade the otherwise
acceptable signal-to-noise ratio of a sound system. Drastic equalization can result in a loss of 20dB or more signal-
to-noise. dbx Type III™ Noise Reduction was engineered specifically for applications such as this. It provides up to
20dB of noise reduction, thus restoring the dynamic range necessary for even the most demanding professional
sound systems. The combination of proper wiring, proper gain structure and TYPE III™ Noise Reduction should
render your sound system virtually noise free.
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The dbx 20 Series EQs are all solid-state products with components chosen for high performance and excellent reli-
ability. Each unit has been tested and burned-in at the factory. No adjustment of any type should be required
throughout the life of the unit.
If circumstances arise which necessitate repair, we recommend that your EQ be returned to the factory. This can
only be done by receiving a RETURN AUTHORIZATION number from dbx customer service.
If you require technical support contact Customer Service. Be prepared to accurately describe the problem. Know
the serial number of your unit (printed on a sticker attached to the chassis of the unit).
Contact information is printed on the back cover of this manual.