Aux3 - Dynacord PowerMate 2200 Mode D'emploi

Generally, the AUX3 channel is used as monitor bus. Depending on the setting of the AUX3
POST switch, it is also possible to confi gure the bus for the connection of an additional, exter-
nal FX unit.
33. AUX3 SEND
This output is meant for the connection of an external FX unit, a power amplifi er or active sta-
ge monitor speaker systems, when the AUX3 bus is used for monitoring purposes. Using the
AUX3 fader, the output level can be adjusted in a wide range up to +20dBu. The AUX3 send
is designed in Ground Sensing technology to prevent the induction of external noise, even
when longer cables are involved.
34. FEEDBACK FILTER
The feedback fi lter is a very narrow banded notch fi lter which is only active in a range that
is extremely susceptible for acoustical feedback. The frequency band is set, using the cor-
responding rotary control. The fi lter is activated by pressing the corresponding ON switch.
Acoustical feedback is originated when the amplifi cation rate in a signal loop, consisting of
microphone, amplifi er, and loudspeaker systems, and regarding its phase coherence and the
distance between speakers and microphone, is not clearly negative. Or in other words: the
speaker signal hits the microphone and gets amplifi ed again, resulting in an escalating oscil-
lation, which is audible as high pitched whistle or loud humming sound. However, explaining
all factors that are relevant for the occurrence of feedback would lead to far. The following
notes are meant to assist you in avoiding feedback and you should take them into considera-
tion even before you activate the feedback fi lter.
1. Do not position the main speaker systems behind the microphones.
2. Turn off all unused microphones.
3. Also consider the microphones' different polar patterns and characteristics, when
placing the monitor speakers.
4. Do not turn up the monitor system's volume higher than really necessary.
5. Try to avoid extensive equalization on channels that you want to include in your
monitor mix.
6. Keep in mind, that microphones "behave" different when somebody stands right in
front of them. In fact, the amount and intensity of fi rst refl ections changes drastically.
7. Position the microphones as direct as possible to the sound source.
If you still have the feeling that the monitor system's volume is not high enough, after conside-
ring the above mentioned precautions, you can use the feedback fi lter to mute the frequency
that tends to generate feedback the most. Therefore, you have to perform the following steps:
Increase the AUX3 (monitor) level until the limit where feedback starts. The "sound" you hear
is generated within the system. Turn on the feedback fi lter and adjust the rotary control at the
mark where the "sound" disappears. Switching the fi lter on and off lets you easily check if you
tuned in the correct frequency. The feedback fi lter attenuates the corresponding frequency
band by about 9dB. Since the fi ltered band is extremely narrow, an alteration in the sound of
your monitor system is hardly audible.
CAUTION: Please be extremely careful when you increase the level up to the feedback limit.
Careless operation, resulting in feedback noise at high SPL, can severely damage your spea-
ker systems and – even more important – the human ear.
35. AUX3 POST
As mentioned before, this switch is used to determine if the AUX3-mix signal is PRE or POST
FADER. In case the switch is engaged and the yellow LED lights, the signals of all AUX3 con-
trols in the input channels are split post their corresponding channel faders.
36. PFL
Through this button you can route the pre AUX3 fader signal to the headphones bus. The si-
gnal is outputted via the headphones output. The setting of the AUX3 fader is not relevant for
the signal's volume (PRE FADER LISTEN), leaving you with the opportunity to adjust its level
and equalization without the need to route it to the AUX3 SEND bus.
37. AUX3 VOLUME
This fader controls the AUX3 SEND output level. So when the AUX3 bus is used for monito-
ring, this fader lets you control the volume of the monitor system.
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AUX3