Starting Up; Starters' Guide To Equalizers - Omnitronic GEQ-215 Mode D'emploi

The occupation of the connection-cables is as follows:
Cable Pin
Brown Live
Blue Neutral
Yellow/Green Earth
The earth has to be connected!
If the device will be directly connected with the local power supply network, a disconnection switch with a
minimum opening of 3 mm at every pole has to be included in the permanent electrical installation.
The device must only be connected with an electric installation carried out in compliance with the IEC-
standards. The electric installation must be equipped with a Residual Current Device (RCD) with a maximum
fault current of 30 mA.

STARTING UP

Make sure to power-up before your power amplifier is turned in order to avoid loud transients which could
damage your speakers or annoy your audience.

STARTERS' GUIDE TO EQUALIZERS

At first glance, a graphic equalizer may appear to be a complicated device, but actually, in theory and
operation, a graphic equalizer is a very simple device. Most people are familiar with bass and treble tone
controls. These controls work by dividing the audio signal into two frequency bands - the low frequencies and
the high frequencies. The bass knob, then, effectively becomes a volume control for the lows and the treble
knob gives us volume control over the highs.
"Hz" stands for "Hertz". "KHz" stands for "thousands of Hertz". These are measures of sound-cycles per
second. You see, sound waves are measured by the number of cycles or vibrations they make in one
second. Very low-pitched sounds like bass guitars have far fewer cycles per second than high-pitched
sounds like cymbals. So, if you want to increase the volume of the cymbals in a recording without affecting
the volume of the bass guitar, use the treble control.
The cymbals occupy only a very small band of frequencies within those controlled by the treble control. Also
included in the range of the treble control are vocal sounds. They occupy a similarly narrow band of
frequencies somewhat lower than the cymbals. A treble control alone does not offer enough flexibility of
control to allow us to increase the volume of the cymbals without also increasing
the volume of the vocals. What is needed is a type of control that divides the audio signal, not into two
bands, but as many bands as possible. This would allow us almost unlimited flexibility of control over the
tone "colors" in our audio program.
That's exactly what a graphic equalizer allows us to do. It gives us precise control over the volume of
manynarrow frequency bands, each of which can add (or subtract) their own particular tone "color" to our
overall sound.
In the recording studio and on stage, graphic equalizers are generally used for three distinct purposes:
1.) ROOM EQUALIZATION: Every room adds its own "character" to the sound of music played in it because
of the way the walls, floors, ceilings, furnishings and people absorb or reflect the sound waves. Every room
boosts some frequencies and attenuates others in this way. So graphic equalizers are used, in this context,
to compensate for the "damage" done to the sound by the room itself.
2.) FEEDBACK CONTROL: Without a graphic equalizer, it is quite difficult to stop feedback (that piercing,
whistling sound that happens when microphones pick-up and reamplify the sound from the speakers). A
graphic equalizer can zero in on the offending frequency and reduce it, leaving the rest of the music
unchanged.
3.) CREATIVE RECORDING: Graphic equalizers are routinely used to make certain sounds "brighter" or
"fuller" or even radically different, depending on the creative whims of the operator. A voice can be made to
sound as though it's coming through a telephone line, for example. An acoustic guitar can be given a metallic
sparkle. A kick drum can get more "snap". It may be a cliché, but it's true: With a graphic equalizer, you are
only limited by your own imagination!
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