Using Equalization And Shape - Hartke B Bass Combo Série Mode D'emploi

Using Equalization and Shape

The Hartke Systems B Series Bass Amplifier gives you enormous control over shaping the sound
of your bass, using a process called equalization. To understand how this works, it's important to
know that every naturally occurring sound consists of a broad range of pitches, or frequencies,
combined together in a unique way. This blend is what gives every sound its distinctive tonal
color. The B Series EQ controls allow you to alter a sound by boosting or attenuating specific fre-
quency areas—they operate much like the bass and treble controls on your hi-fi amp, but with
much greater precision.
The B Series offers three bands of equalization. Each EQ knob (labeled Bass, Mid, and High,
respectively) affects a different frequency area (100 Hz, 830 Hz, and 5 kHz, respectively) and
provides approximately 15 dB of boost and attenuation. We carefully selected these frequency
areas because they have maximum impact on bass signals. For example, the Low (100 Hz) con-
trol affects the very lowest audible frequencies (in fact, most humans cannot hear below 20 Hz),
while the High (5 kHz) control affects the "twang" of a bass string.
When an EQ knob is in its center detented position ("0"), it is having no effect. When it is moved
right of center, the particular frequency area is being boosted; when it is moved left of center, the
frequency area is being attenuated. Turning all EQ controls up the same amount will have virtu-
ally the same effect as simply turning up the Volume; conversely, turning them all down the same
amount will have virtually the same effect as turning down the Volume. Both approaches are
pointless (after all, that's why we gave you a Volume control!)
In many instances, the best way to deal with equalization is to think in terms of which fre-
quency areas you need to attenuate, as opposed to which ones you need to boost. Be aware
that boosting a frequency area also has the effect of boosting the overall signal; specifically, too
much Low EQ boost can actually cause overload distortion or even harm the connected speaker.
In addition, the B600 and B900 models provide a unique Shape control which employs a notch
filter to remove specific frequency areas. At the same time, it overlays a special equalization curve
that is designed to improve the sound of electric bass instruments. This curve provides boost
at certain frequency areas and attenuation at other frequency areas. As the Shape knob is turned
clockwise, the notch filter is imposed on higher frequency areas; as it is turned counterclock-
wise, the filter is imposed on lower frequency areas. At the fully clockwise position, the filter is
applied to the 1 kHz frequency area, making for a deep, rich tone; at the fully counterclockwise
position, the filter is applied to the 90 Hz frequency area, making for a bright, twangy tone.
The specific EQ (and/or Shape) you will apply to your bass signal is very much dependent upon
your particular instrument and personal taste and playing style. However, here are a few general
suggestions:
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