Operating Tips - Yamaha MC1204 Operating Manual

OPERATING TIPS
Matching Input Channel Sensitivity with the Source
The pad switch and continuously variable gain control
provided on the mixer's input channels permit setting
the input sensitivity of each channel anywhere between
- 60 dB and 0 dB. With the pad switch set at 0 dB
(pad out) the gain control adjusts sensitivity between
- 60 and - 20 dB, while with the pad switch set at
- 20 dB (pad in) the gain control adjusts sensitivity be ­
tween - 40 and 0 dB . This makes it possible to ideally
match the mixer's input sensitivity with a broad range
of input sources.
In general, an input sensitivity setting of about - 50 dB
is commonly used with low output dynamic micro ­
phones, - 40 dB with medium output condenser micro ­
phones, - 20 dB with electric instruments (preamplified)
and low level (creative audio or hi-fi) line sources, and
o
dB with high level line sources (such as some profes­
sional equipment line outputs).
Set the input level switch to correspond to the type of
device that is plugged into the corresponding Channel
Input jack. Here is one suggested procedure:
1. Connect all input sources to their respective chan ­
nels. Plug in and wear your headphones to hear the
program mix. DO NOT CONNECT any power
amplifiers or speakers yet.
2. Set up the mixer so that the signal from each input
channel feeds the STEREO mixing buss, and set all
channel faders at infinity (minimum). Raise the
STEREO L master fader to about " 6" on the scale.
3. Start with the lowest input sensitivity (pad in, gain at
- 20). Bring the channel fader up to "6" on the
scale If necessary, gradually increase sensitivity us ­
ing the gain control until the input is clearly audible.
If sensitivity is still too low, return the gain control to
the - 20 dB setting and set the pad switch to 0 dB,
then gradually increase the gain control setting once
again . The STEREO L program VU meters should
peak around "0 VU". If the meter consistently shoots
past "0 VU", or if the signal sounds distorted in your
headphones, the input sensitivity is set too high;
decrease the input sensitivity until the levels are
correCt.
The input peak LED may also be used as a visual
aid in adjusting the gain control. If the peak LED is
on continuously the gain control is set too
high-reduce the gain control level. Normally, the
peak LED will light occasionally on louder musical
passages (peaks or transients).
4. Repeat the procedure for each input channel, until all
channels are set for proper input sensitivity. Turn the
Mixer Power Off, and connect your outputs. Turn the
mixer power ON again . You are now ready to adjust
the remaining controls on each channel.
NOTE:The
console and all signal processing devices
connected to it MUST be turned on before
the power amplifiers are turned on, or the
turn-on transient could easi ly cause irrepa­
rable damage to your
loudspeakers. This pro­
cedure should be reversed when the system
is turned off.
Using the Channel EO Controls
The Low-EO control adjusts the channel's frequency
response through the low-frequency range. The control
has no effect ("flat response " ) when centered. Low EO
boost (clockwise rotation) gives more " fullness " to
vocals, guitars, etc., and more of a mellow character to
horns and woodwinds. Low-EO cut (counterclockwise
rotation) removes boominess, avoids some of the
excessive energy from drums, and reduces 50 or 60
cycle hum, and stage rumble .
The Mid-EO control permits peaking boost or cut
equalization at the frequency determined by the setting
of the MID FREO control (0.35-5 kHz). Boosting the
midrange (especially at around 2.5 or 3 kHz) can great ­
ly increase the overall "presence" of the sound.
Vocalists will seem to come forward and stand out from
the instrumental backing . Cutting the mid-frequencies
has the opposite effect -vocals seem to recede and
the overall sound becomes " thinner". It is often effec ­
tive to cut the midrange response of the instrumental
backing just slightly, and boost the vocal channel
midrange a little in order to make the vocals stand out
with exceptional clarity.
The High-EO control adjusts the channel's frequency
response through the high-frequency range . High -EO
boost (clockwise rotation) gives more "edge" or "bite "
to string instruments and more " attack " to percussive
instruments. High -EO cut (counterclockwise rotation)
removes some of the breath sound from wind instru­
ments, reduces guitar ·string fingering sounds, lessens
hiss, and avoids sibilant (Iispy) vocal sounds. High-EO
cut also helps to make a performer sound farther
away, particularly if reverb is added. The equalizer
can be helpful in avoiding feedback, too.
Care should be taken not to "over-equalize" any given
channel. Using drums as an example, moving the
microphone as little as one inch (2.5 cm) can alter
its tonality significantly-without having to adjust the
channel equalizer. Also, the type of microphone used
can greatly affect the tone achieved. Experiment with
different microphones and microphone placement for
the best results in your application. A little care in
mic placement can save a lot of time trying to " fix
it in the mix".
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