YORKVILLE VGM14 Owner's Manual page 8

Mono
Channel
4
5. Input Channel Audio Compressor
Each of the mono input channels of the VGM14 (channels 1-10) has an internal dual-
slope soft-knee audio compressor. The VGM14's compression function is suitable for
keyboards, percussive sources, and vocals.
A compressor reduces the dynamic range of the music providing a more constant
level. Like having a sound engineer dynamically adjusting the gain of each channel
for the optimum audio level.
The VGM14 compressor works automatically in the background. It can reduce clipping
of the audio signal during loud passages in the music which provides a tighter sound
typically heard in audio recordings. You can adjust how much compression you want with
the input channel Gain control.
Here is how to use the compressor: in automatic mode, set the Gain level so that
the Set Level LED is just blinking to the music. The compressor will remain off until
someone yells into the microphone or there is a loud percussive sound, then the com-
pressor will lower the gain, reducing the possibility of clipping. To adjust for little to no
compression, have the music source playing into the input channel. Turn up the input
channel Gain control to the point where the Set Level LED is just blinking with the
music. At this point the full dynamic range of the music source will be experienced.
Continuing to turn the input channel Gain control clockwise, the music will get louder.
To maintain the same audio level turn down the Channel Fader for the channel being
adjusted. The further the input channel Gain control is turned clockwise, or the louder
the music source becomes, the greater the compression will be experienced.
If the Clip LED blinks occasionally then the maximum amount of compression has
been reached. If the Clip LED remains on for longer periods, turn down the input Gain
level until the Clip LED blinks occasionally.
6. High Pass Filter Button
Situated at the top of the channel strip, this switch activates a High-Pass Filter (a bass
roll-off of 18 dB per octave below 80 Hz). The HPF (High-Pass Filter) is useful for control-
ling unwanted low-frequency spillover picked up by microphones located too close to the
bass drum, bass amp or the keyboard amp. It is also effective in optimizing acoustic guitar
pickups that sound boomy from the guitar body resonance (the lowest note on a concert-
tuned guitar is 81.2 Hz, so you are not losing anything by rolling off the input response
below 80 Hz). Additionally, the HPF works to reduce breath pops and wind noise from vocal
microphones. Any microphone, or pickup, connected to a source that does not go below 80
Hz should have the HPF activated. This includes most wind instruments, most male voices,
nearly all female voices and all drum microphones except for the kick-drum.
Why roll off the bass on these channels? ...Because you will get better sound clarity
and improve the system's gain before feedback.
7. Mono Channel EQ
The VGM14's mono channels feature 3-band Equalization consisting of Low and High shelv-
ing filters and a sweepable Mid control. The Low and High shelving filters are preconfig-
ured at 80 Hz and 12 kHz with a control range of +/-15dB. The sweepable Mid EQ has a
selectable frequency range from 150Hz to 5 kHz, with a control range of +/-15dB. The tone
control frequencies were carefully chosen to help achieve the best quality of sound.
It's best to set the channel EQ during a sound check. It is best to minimize the amount of
EQ "boost" or "cut" you add to the audio. +/-15dB represents a considerable level change.
For vocals turning the Low control counterclockwise will reduce the boominess of
male voices. For male or female vocals it will also "clean up" the mix, as this channel
will reduce the bass sound from instruments heard by this microphone.
The Mid control is a very powerful because adjusting it affects the tone of any music
source. Including the sweep frequency control makes the mid EQ even more useful albeit
more complicated. A good rule-of-thumb to follow is, use as little boost and cut as pos-
sible to the signal. If a vocal, or instrument, sounds "honky" you would typically "cut" (or
turn the Mid control counter clockwise) in order to reduce the selected mid frequency. You