A small presentation about the various types of graphical equalizers and related basic terms used....

1. Various Types of
Equalizers
Audio Ksharing: Rajesh Sharma

2. 1Types of Equalizers
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Why Use an Equalizer
Two fundamental reasons for using an
equalizer
To increase the naturalness or intelligibility
of the sound system e.g. to create a flat
frequency response sound system.
To increase the gain or volume of the
system before feedback occurs
Audio equalizers have operating frequency
range of 20Hz-20KHZ
Boost/Cut Range is normally , in some
steps.
dB12±

3. 2Types of Equalizers
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Position
Equalizers are generally positioned in the
system signal flow between mixer and power
amplifiers.
Though it can also be used independently for
each mixer channel.

4. 3Types of Equalizers
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Bandpass Filter Parameters

5. 4Types of Equalizers
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Cont….

6. 5Types of Equalizers
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Shelving Filter Equalizer
Most basic of all:
Used in home stereo systems and basic sound
system, mixer/amplifiers
These equalizers have three knobs
Bass: Low Pass Filter, below 100 HZ
Treble: High Pass Filter, above 10KHZ
Mid: : Band Pass Filter, also known as Peeking
Filter

7. 6Types of Equalizers
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Graphic Equalizer
One can graphically see the equalizer response
from settings
Constant-Q, Proportional-Q, Perfect Q are
various Technologies.
Three basic types of graphic equalizer:
Octave Band Equalizer: 9-10 Bands
2/3 Octave Band Equalizer: 15 Bands
1/3 Octave Band Equalizer: 27-30 Bands

8. 7Types of Equalizers
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Parametric Equalizers
Big Boss of all equalizers:
Three Knobs/Band Controls:
Boost/Cut Control
Center Frequency Control
Band Width Control
These equalizers have usually 3-4 bands for
Analog Equalizers and may have 10-20 for
Digital Equalizers.

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Semi-Parametric Equalizer
In these equalizers, few of the bands have fixed
bandwidth and center frequency.
For example, low/high pass filters are fixed and
the rest have three controls like in parametric
equalizers.

10. 9Types of Equalizers
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Mono/Stereo Equalizer
Mono Equalizers have same equalization
applied to both channels
Stereo Equalizers have independent
equalizations for both channels.

11. 10Types of Equalizers
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Digital automatic feedback controller
These equalizers systems sense feedback and
insert a very narrow filter on the offending
frequency
It is like a parametric equalizer which is set
automatically

12. 11Types of Equalizers
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Programmable Equalizers
It is like any other equalizer
But it also allows multiple settings to be stored
for future use

13. 12Types of Equalizers
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Channel Equalization
Following two equalizations are used for
channel equalizations
Blind Equalization
Adaptive Equalization

14. 13Types of Equalizers
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Usage
Equalization of the loudspeaker system
Compensation for loudspeaker placement
Compensation for room acoustic
To reduce feedback
Compensation for the microphone
characteristics and placement
To create special effects