Yorkville VGM14 - Manuel (Page 14)

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8. Main (L/R) and Mon Graphic Equalizer
The VGM14 features a stereo 9-band Graphic Equalizer which is assignable for use with
the Main or Mon mix. The Equalizer’s adjustment range is +/-12 dB with frequency centers
at one-octave intervals from 63 Hz to 16 kHz.
Using the Equalizer Assign switch in the Main position, you can adjust the main
speaker response during a sound check (be careful, do not use radical boosts). This
might be useful for minimizing feedback but remember; stage monitor speakers are
most often the cause of feedback.
Naturally, stage monitor feedback will also be heard out the main speakers at the mixer
station, which can lead you to the illusion that the main system is the cause. Therefore, to
minimize stage monitor feedback, place the EQ Assign switch into the Mon position.
First set up your mixer with the proper channel Mon level settings. Turn the Main fader
to the minimum gain position and make sure that the Equalizer faders are all set to 0 dB.
Now slowly turn up the Mon fader until feedback begins, then turn down the Mon fader to
keep the feedback from getting too loud. Try to figure out, the best you can, the frequency
of the ringing tone; reduce the Mon EQ fader closest to the frequency of the feedback. You
should only need to reduce the fader by about -3 dB on Equalizer scale.
For a second ringing tone, turn up the Mon fader again, cautiously, to the onset of feed-
back again. Try to figure out the frequency of the second ringing tone, it will most-likely
be different from the first feedback frequency. Finally, reduce the Mon Equalizer fader clos-
est to the frequency of the feedback. Now you can turn up your Main fader, and reduce
your Mon fader to obtain the proper gain for both signals with reduced feedback.
You can continue this process to find the third and fourth feedback frequencies.
You can use an outboard graphic equalizer or other digital processor, for the output not
assigned to use the internal Equalizer by connecting it to the appropriate output of your VGM14.
When setting the Main Equalizer, do not automatically set to a ‘smiling’ curve as with
a home stereo – this will cost your system both headroom and gain before feedback.
Initially, keep the Equalizer curve as close to flat (all sliders at center) as possible; then,
make necessary (minor) adjustments as needed during a sound check to cut feedback
frequencies. Again, you should only need to reduce the graphic Equalizer’s faders to
about -3 dB on the front panel EQ scale.
9. Phones Level
The Phones level control adjusts the stereo audio level to the headphones plugged into
the Phones jack. The audio signal for the headphones is post Main Equalizer so that you
can hear the same audio signal on the Main Out phone and Main Output XLR jacks.
The Phones (headphones) jack is a stereo jack compatible with headphones having an
impedance down to 8 ohms but we recommend for best performance using headphones
with an impedance of 80 ohms or higher.
10. Zone/Sub Level
The Zone/Sub level control adjusts the audio level of the Zone/Sub signal. The post Main
fader left and right channels are summed and sent to the Zone/Sub level control. The
output of this control goes to the Zone/Sub TRS phone jack located on the back panel.
Used as a separate adjustable mono output, the Zone/Sub signal can provide audio
for a distributive audio system, or fill loudspeakers, used with the main loudspeaker
system. You can also use the Zone/Sub audio signal for powered subwoofers adding the
convenience of a level control at your console. To control crossover point, a crossover
control typically is located on the powered subwoofer’s control panel.