Owner's manual

4.7 Frequency Control.
This control sets the Frequency on each band that is to be cut or boosted. The
frequencies are variable over the following ranges:
LF band: 30Hz to 1kHz
LM band: 100Hz to 3kHz
HM band: 1kHz to 12kHz
HF band: 3kHz to 20kHz
4.8 Q (Bandwidth) Control.
The “Q” of the filter is a measure of the shape of the frequency response
curve, and is closely related to the ‘bandwidth’ or range of frequencies
controlled by the filter. A narrow bandwidth (high Q) setting means that a tight
band of frequencies either side of the selected centre frequency is affected by
any cut or boost actions, while a wide bandwidth (low Q) affects a much
broader band of frequencies.
As a result, high Q settings (about 5 at the maximum setting on the 5013) are
generally used for audio correction or effects - for instance when a single
troublesome frequency needs to be removed without upsetting the rest of the
frequency spectrum, or a single frequency needs to be boosted to create a
particular unique sound. A proven technique for identifying frequencies is to
set the Q control to its minimum (narrow) position, apply a reasonable amount
of boost in that EQ band, and then sweep the Frequency control around until
the problem (or desired) frequency is found (since boosting will make the
frequency prominent). Cut (rather than boost) can then be applied if the
frequency is troublesome, and if necessary the Q can be widened to take out
a broader band of frequencies.
Intermediate Q settings, say 1 to 3, are generally used to enhance or reduce a
broader range of frequencies, typically to make an instrument or vocal stand
out - or recede - into the mix. Finally, low Q values (down to about 0.5 on the
5013) provide gentler contouring, or “sweetening” of the response.
4.9 Shelving EQ.
The low frequency and high frequency sections offer either peaking or
shelving equalisation by means of a pull-out switch on the Q control. When the
knob is pulled ‘out’ the Q control itself becomes inactive and the section will
process any frequencies
below
the selected frequency (in the LF band) or
above
the selected frequency (in the HF band) with a slope of 12dB per
octave. Shelving EQ can be used to “roll-off” low or high end frequencies or to
boost all frequencies above or below the one selected by the variable