Shelving Eqs; Single Band Eqs - Alesis 2 Reference Manual

Lowpass Shelf and Highpass Shelf
A shelving EQ can boost or cut frequencies in its pass band, while allowing the
frequencies outside its pass band to go through it. The shelving EQs of the
QuadraVerb 2 provide gains from -14dB to +14dB in 0.1dB increments. Shelving
filters are well suited for applications in which high or low frequencies need to be
boosted or cut, but the remainder of the audio signal is to pass through unchanged.
Applications for shelving EQs include removing high end hiss, and "tightening up"
the sound of a bass instrument. The Highpass Shelving EQ is useful to compensate
for a lackluster source that needs its high end brightened. The Lowpass Shelving EQ
can be set to cut low frequencies to eliminate PA rumble.
+14dB
+11dB
0dB
-11dB
-14dB
Lowpass Shelving EQ

Single Band EQs

1 Band Low Parametric and 1 Band High Parametric
A single band parametric EQ allows frequencies within its passband to be amplified
(boosted) or attenuated (cut) while allowing the remainder of the audio information to
pass through unchanged. The QuadraVerb 2 provides a low frequency version (20Hz
to 2000Hz), and a high frequency version (1500Hz to 10kHz). Single band parametric
filters work well to highlight specific frequencies in a mix; for instance, bringing a
tambourine to front and center, or boosting a repetitive bass line to achieve a realistic
"inner-city throb".
+14dB
+11dB
0dB
1 Band Parametric
(boost w/ low bandwidth)
QuadraVerb 2 Reference Manual
Gain = +14dB
(boost)
Cutoff
Frequency
Gain = -14dB
(cut)
Bandwidth
Center Frequency
Overview - Chapter 3
+14dB
+11dB
Gain = +14dB
(boost)
0dB
Gain = -14dB
(cut)
-11dB
-14dB
Highpass Shelving EQ
0dB
Center Frequency
Bandwidth
-4dB
-7dB
1 Band Parametric
(cut w/ high bandwidth)
Cutoff
Frequency
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