Speck Electronics EQ16 - Manual (Page 24)

Bandwidth (Q)
The bandwidth of the selected frequency is automatically adjusted with
the selection of the frequency sweep control. The lowest setting on any
band will result in a narrow bandwidth of approximately 11 dB/octave
(Q = 3.3). As the frequency sweep control is adjusted to its highest
setting (fully clockwise), the bandwidth widens to approximately
4 dB/octave (Q = .8).
Example:
"Q" (Q factor) is another method of defining bandwidth and requires a
small mathematical calculation. "Q" is the ratio between the selected
center frequency and the -3dB down point bandwidth of that frequency.
This control provides 15dB of bell shaped boost or cut for the high
frequency range (5kHz to 15kHz), and is used in conjunction with the
high frequency sweep adjust (see item 2). 0dB boost/cut (flat) is
obtained when this control is set to its center position.
The high frequency sweep control is used in conjunction with the high
boost/cut control and provides continuous adjustment from 5kHz (fully
counterclockwise) to 15kHz (fully clockwise).
In addition to the ability to contour high band audio, the high band
controls can reduce hiss that is present on low frequency information. If
there is high frequency hiss or digital noise on a kick drum or bass track,
the high sweep control may be set to its highest clockwise setting
(15kHz) and its associated boost/cut control "cut" a few dB's.
20
1. High boost/cut
2. High frequency sweep
Refer to Figure 10 for location of items 1 thru 7.
formula: Q = Center Frequency / Bandwidth
When the "mid band frequency sweep" control is set to its
fully CCW position of 500Hz, the bandwidth is
approximately 11dB/octave. Therefore, an octave above the
500Hz setting (1000Hz) and an octave below the 500Hz
setting (250Hz) is affected 11dB less than its 500Hz center
frequency when the "boost/cut" control is adjusted. This is
considered a relatively narrow bandwidth.
When the "mid band frequency sweep" control is set to its
fully CW position of 5kHz, the bandwidth is approximately
4dB/octave. Therefore, an octave above the 5kHz setting
(10kHz) and an octave below the 5kHz setting (2.5kHz) is
affected 4dB less than its 5KHz center frequency. This is
considered a relatively wide bandwidth.
Chapter 4 Operation Section