Yamaha Q2031A - Manual (Page 5)

O
EQ switch
When the EQ switch, provided for each channel, is off, the
equalizer is bypassed. When the switch is on, its associated
LED indicator lights, and the equalizer is switched into the
audio path. The equalized signal can be compared with the
un-equalized signal simply by alternately turning the EQ
switch on and off.
O level controls
Individual LEVEL controls for both channels adjust the
input sensitivity for optimum input level. When the LEVEL
control is at the top of the scale, the input source signal level
remains unchanged (+4 dB or —20 dB). As the LEVEL
control is moved downward, the input level is reduced.
This control can be used restore the output level when the
overall level has been changed during the equalization process.
This, however, will also change the input level. Equalization
methods which do not change the LEVEL control setting
will yield a better signal-to noise ratio and wider dynamic
range.
O HPF (High Pass Filter) controls
The HPF controls continuously adjust the rolloff frequency
over the entire 20 Hz to 200 Hz range for their associated
HPFs and channels. Below the selected frequency, there will
be a 12 dB per octave rolloff.
The HPF can be adjusted to eliminate low-range standing
waves that sometimes occur in indoor environments, control
vocal “pops” and wind noise in microphones, and reduce
AC hum.
O Equalizer Boost/Cut controls
The 20 Hz to 20 kHz spectrum is divided into thirty-one 1/3
octave bands, each of which has an equalizer boost/cut slider
center (0) detected position. Moving the slider up boosts that
band, moving it down cuts that band.
Convenient scales on either side of the sliders are calibrated
in dB. The H-/—12 dB range is used when the RANGE switch
is off. When the RANGE switch is on, the +/—6 dB range is
used, and the true values are one-half of the calibrated values.
Peak LED indicators on the right of the RANGE switches Q
light when the output level reaches 3dB below clipping. If
the PEAK indicators remain lit, you should reduce the over­
all settings of the equalizer sliders.
100 200 500 Ik
FREQUENCY (Hr)
To get the best performance from your 31-band Q2031A
stereo graphic equalizer, it is important that you understand
the frequency components that make up the sounds of each
musical instrument. The following graph is provided to aid
this understanding. You should also bear in mind that
harmonics of fundemental frequencies, plotted as dotted
lines in the graph, can have a significant impact on timbre.