About Equalization - Hartke LH500 Owner's Manual

About Equalization

The Hartke LH 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 LH Series EQ controls allow you
to alter a sound by boosting or attenuating specific frequency areas—
they operate much like the bass and treble controls on your hi-fi amp,
but with much greater precision.
The LH Series tone stack equalizer offers three bands of "boost
only" equalization. Each EQ knob (labeled BASS, MID, and TREBLE,
respectively) affects a different area of the frequency spectrum. Since
the LH series equalizer is comprised of boost only filters, when you
turn all the EQ knobs down, the sound will go completely off (unlike
an typical PEAK EQ circuit). When all three EQ knobs are in their center
positions ("5"), the response is actually set to a preset equalization
curve, with a low and high-end boost and a mid-range cut, producing
an EQ contour (at Hartke, we like to say, SHAPE) that sounds great
for bass. In general, when an EQ control is moved right of center,
the particular frequency area is being boosted; when it is moved left
Equalizer controls
of center, the frequency area is being attenuated (or less boosted).
However, the LH series EQ controls are somewhat interactive, since
electronically, the BASS feeds the MID, which feeds the Treble. So,
experiment with the LH Series EQ and your particular bass to dial
up the best sound. The most important thing to know about the LH
equalizer is that it's extremely musical and sounds great with all EQ
knobs set to "5". Actually, it's hard to make LH series EQ sound bad.
Turning all EQ controls up the same amount will have virtually 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 addition to the three EQ controls, the LH Series also includes a BRITE
switch, which will add an overall boost to the high-end frequency
response. Use the BRITE switch in conjunction with the EQ to control
your tone.
In many instances, the best way to deal with equalization is to think
in terms of which frequency 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.
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