Yorkville VGM14 - Manuel (Page 9)

5
might also try to dial the boost control into the 2 o’clock position and rotate the frequency
control from 150 Hz to 5 kHz which might help you to find the annoying frequency in the
audio source. Then, with the frequency control set to that particular annoying frequency,
slowly turn the Mid level control down to the (-) side of “0” to obtain the best sound.
One possible cure for a bad feedback problem is to use the sweepable Mid EQ to
attenuate only the frequency that is causing the feedback. That way, fewer innocent
frequencies are affected. Simply set the Mid level control to the 10 o’clock position
then slowly rotate the sweep frequency control from 150 Hz to 5 kHz until the feedback
stops. Now turn the Mid level control up slightly to normalize the frequency response
as much as possible without feedback.
Cymbals can sound hotter, or an instrument can sound brighter, when you boost the High
EQ control. Be cautious and only add a little boost. Too much boost can be the cause of
the dreaded, squealing feedback. Cutting the High EQ setting can reduce hiss coming
from some audio sources, and may make some bass toned instruments sound warmer.
Although frequency sweep controls have graced the channel EQs of recording mixers
for many years, they’re usually found on more upscale P.A. mixers used for live applica-
tions. As a result, many P.A. users, even veterans, are a little unfamiliar with their func-
tion. The Sweep control determines the range of frequencies that are affected by the Mid
cut/boost, it moves (or sweeps) the Mid control’s peak (or notch) in response up to sev-
eral thousand Hertz, or down to below 100 Hz. As a result, it may have quite a noticeable
effect on the sound quality, especially since the MID cut or boost will be interacting
with whatever cuts (or boosts) you may have set with the Low or High EQ controls.
The Sweep control can shape the sound similar to the way a typical EQ does but more
precise since you have control of the frequency being affected. It is worthwhile to spend
some time becoming acquainted with how it works.
Be cautious, if you boost the Low tone control and then add a Mid boost at 150
Hz, this would create a situation of overlapping boosted frequencies. This can
potentially damage your woofers due to excessive low frequency content. Simi-
larly, watch out for your tweeters/horns if you set the Mid frequency at 5 kHz at
then turn up the High tone control.
As music plays through a channel on the mixer and speakers, adjust that chan-
nel’s Mid tone control, first boosting, then cutting, and then sweeping back and
forth. (Note: if the Mid control is set to the center position, the Sweep control
will have no effect at all). Repeat the process with the channel’s Low and High
EQ controls at various settings (remember to keep the volume at a safe level).
Note: Setting the Mid Sweep frequency to 2.5 kHz is the same frequency of the
fixed Mid controls on our other mixers.
Together, Mid and Sweep controls can be used to accomplish a variety of tasks from
combating feedback to improving the way things sound through the P.A. or on recording.
Here are some of those tasks and settings:
Note: These are approximate settings only. Use them as a starting point and
“tune around” them.
• Killing feedback? Set Mid at -6 dB and slowly rotate Sweep until the feedback stops.
If needed cut the MID further.
• Bonky sounding snare drum? -6 dB @ 200 Hz (roll off Low EQ -6 dB)
• Boomy bass drum? -6 dB @ 300 Hz (Low EQ @ +6 dB and High EQ @ +3 dB)
• Washy sounding cymbals? -9 dB @ 300 Hz (roll off Low EQ -15 dB)
• Excessive hiss from guitar, bass or keyboard amp? +3 dB @ 5 kHz (High EQ
rolled off -9 dB)
• Fading vocal range (notes too low for singer)? +3 dB @ 80 Hz (Low EQ rolled off -6 dB)
• Puffing on harmonica mic? -9 dB @ 80Hz (Low EQ rolled off -12 dB)
• Rack Toms? -3 dB @ 400 Hz
• Floor tom? -6 dB @ 200 Hz