Yamaha EM-300B Operating Manual page 13

RESPONSE Id8)
Lor "P
A pair of VU Meters indicate the average power
level at the Speaker outputs. Actual mix levels should
average several dB below 0, with occasional peaks as
high as O VU. Clipping distortion begins when the VU
meter reaches full scale. The meters are illuminated,
and the meter lamps also serve as AC Power pilot lights.
QD issu e
o
50. 39 00
8
m
UM
YAMAHA . `:
VU YAMAHA | . VU >
PROGRAM
VU meters
The Monitor Output jacks are line-level, high-
impedance outputs. They are designed to drive external
monitor amplifiers, or they also may be used to make
tape recordings. (Since one monitor output is pre-EQ
& fader, and the other is post-EQ & fader, a true stereo
mix would be difficult to achieve here.) The Master
Monitor faders set the level at the Monitor Outputs, and
are independent of Master Program faders. inputs
` connected to the Monitor Sub In jacks will appear, but
inputs connected to the Auxiliary Input jacks will not
appear in the Monitor Outputs.
Master Controls
A special feature of the EM-Series | Mixers are the
Graphic Equalizers. Seven sliders per channel on the
ЕМ-15011В and nine on the EM-200B and EM-300B
alter the frequency response of the Mixer's Left or
Right Program outputs. These sliders differ from the
channel ЕО controls in that each operates over a
limited range of frequencies. (One-octave band centers
on the EM-200B and EM-300B.) Each G-EO slider is.
center detented; it "clicks" at the center ("'flat'") point
of its boost/cut range. These equalizers provide far
more flexibility than typical tone controls. Acoustic
feedback can be reduced by lowering the slider which
covers the frequency range where the feedback occurs.
Feedback frequencies can be estimated by comparing
them to notes on a piano or other instrument {middle
C" is 256 Hz, one octave above is approximately 512 Hz,
etc.).
. ЕЕ
[T]
"T ТГ ИГ]
ANS IN CINE ТҮ
' CAIN
| RAN OD }
A К
RESPONSE (98!
ба | Е
ў
А SC ПУ LN LENA
NUNCA CANI
PERTH
VY
pes fesd | кк [ДЕ
EH Т ИШ
1
‫ا‬
TES‫‏‬
ет LA
E
E
TERR TES
FREQUENOY (нг)
FREQUENCY (Hui
EM-1501I1B EM-200B & EM-300B
Feedback control is actually a minor application for
the Graphic Equalizers. Judicious use of the Equalizers
can help the PA system sound more natural in trouble-
some acoustic environments, and can add desired color,
warmth or penetration even in good acoustic
` environments. For example, some clubs have large ,
amounts of sound-absorbing carpeting, draperies,
12
E Neel te 2
furniture, etc. Since absorptive materials affect mostly
the high-frequencies, the sound may be too mellow or
bassy. Other rooms with very hard walls and ceilings,
or hard surfaced dance floors, may sound too bright.
Or perhaps the speaker system is deficient in one
frequency band yet is peaky in another band. i
Adjusting the Graphic Equalizer can compensate
partially for these problems in a way that would be
difficult to achieve with input channel EO controls.
The Graphic Equalizers may also be used for many
special effects. As with any equalizer, greater amounts
of boost or cut cause greater phase shift. Therefore, use
graphic equalization sparingly; extreme settings should
be reserved for solving severe problems or for special
effects. To keep distortion at a minimum, avoid
excessive boost at a single frequency. Since removing
feedback frequencies with the Graphic Equalizers can
also remove portions of desirable program material,
you should first attempt to solve feedback problems
by careful speaker and microphone placement.
The G-EO In and Out jacks on the rear panel allow
you maximum flexibility in using the Graphic
Equalizers. For example, the diagram below shows
how you can assign one Graphic Equalizer to both
program channels (when a mono program is all you
need) using a "Y"' cord, and then take advantage of
the other Graphic Equalizer for the Monitor 1 mix.
Note:
Connect
house speakers
to "speaker"
jacks.
A4115H
Monitor
Speaker
С-ЕО alternate patching for monitors and house. Not
applicable to Model EM-10011.
The Left and Right Master Program Faders
simultaneously adjust the program level at the Speaker,
Headphone, Line, and Graphic-EQ outputs. These
controls operate normally at about #7. Frequent
mixing with the Master Faders at maximum indicates
that the individual channel faders may be set too low,
that the channel Input Level switches are set incorrectly,
that the input sources are of insufficient level to drive
the Mixer, or that the Mixer's amplifier is not powerful
enough to deliver the acoustic levels you want. In the
later instance, you could use additional power
amplifiers and speakers (driven from G-EQ out), or
you could use more efficient speakers.
The Master Monitor Faders (1 & 2) adjust the
program level at the respective Monitor Outputs.
The Aux In Volume controls affect how much of
the Aux In signal is fed to the program mixing buses.