About Equalization - Hartke HA2500 Owner's Manual

About Equalization

30Hz 64Hz 125Hz 250Hz 500Hz 1KHz
Contour controls
+15
IN
0
OUT
-15
30Hz 64Hz 125Hz 250Hz 500Hz 1KHz
30Hz 64Hz 125Hz 250Hz 500Hz 1KHz
+15
IN
0
OUT
-15
30Hz 64Hz 125Hz 250Hz 500Hz 1KHz
Graphic equalizer
30Hz 64Hz 125Hz 250Hz 500Hz 1KHz
+15
IN
0
OUT
-15
30Hz 64Hz 125Hz 250Hz 500Hz 1KHz
The Hartke Systems Model 2500 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 occur-
ring 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. 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 Model 2500 provides
you with two different means for equalizing your bass sound:
•
•
Normally, you will adjust the two Contour controls before "fine-tuning" your
EQ with the Graphic Equalizer. The Low Pass Contour control affects a broad
band of frequencies with 100 Hz as the center point; similarly, the High Pass
Contour control affects a broad band of frequencies with 10 kHz as the cen-
ter point. When either is in its center detented position ("0"), it is having
no effect. When it is moved right of center, the particular frequency area is
2KHz 3KHz 5KHz 8KHz
being boosted; when it is moved left of center, the frequency area is being cut
+15
+12
+9
("attenuated"). Because there is very little bass guitar energy at 10 kHz, the
+6
+3
+2
-2
High Pass Contour control should be thought of as your overall "noise" con-
-3
-6
-9
-12
-15
trol—turning it down (to the left of the "0" position) will help to eradicate hiss
2KHz 3KHz 5KHz 8KHz
and buzz while having very little effect on the bass guitar signal. Similarly, the
Low Pass Contour control, when set left of 0, can be used to eliminate rumble
and "woofiness. "
2KHz 3KHz 5KHz 8KHz
+15
+12
+9
+6
+3
+2
The ten-band graphic equalizer provides ten sliders, each corresponding to
-2
-3
-6
-9
a single narrow frequency band (at 30 Hz, 64 Hz, 125 Hz, 250 Hz, 500 Hz, 1
-12
-15
kHz, 2 kHz, 3 kHz, 5 kHz, and 8 kHz). This allows you to "draw" the desired
2KHz 3KHz 5KHz 8KHz
tonal response of your system. When a slider is in its center detented position
("0"), it is having no effect. When it is moved above center (towards "+15"),
2KHz 3KHz 5KHz 8KHz
the particular frequency area is being boosted; when it is moved below center
+15
+12
+9
+6
+3
(towards "-15"), the frequency area is being attenuated. We carefully selected
+2
-2
-3
-6 these frequency areas because they have maximum impact on bass signals.
-9
-12
-15
For example, the lowest slider (30 Hz) affects the very lowest audible frequen-
2KHz 3KHz 5KHz 8KHz
cies (in fact, most humans cannot hear below 20 Hz), while the highest four
sliders (2, 3, 5, and 8 kHz) affect the "twang" of a bass string.
WARNING: Use caution when raising the 30 Hz slider above 0 if you are
operating at high volume levels (especially if Compression is not being
used) since this can place undue stress on connected loudspeakers.
Low Pass and High Pass Contour controls provide 18 dB of cut or
boost in two broad frequency bands.
A Graphic Equalizer provides 15 dB of cut or boost in ten narrow fre-
quency bands.
10