Montarbo MP4 Manuel D'instructions page 11

Important !
Product care and maintenance
• Never place burning candles or other sources of open flame
on top of the device.
• Never expose the enclosure to heat sources (lamps, lights,
high power light sources, radiators or other products that
produce heat.
• Never expose the enclosure to direct sunlight, excessive
vibrations or mechanical shocks.
• Avoid operating and storing the enclosure in damp or dusty
places: this may lead to malfunctions and premature degrading of
specifications.
• Avoid using the enclosure close to strong sources of
electromagnetic interferences (e.g. video monitors, high power
electrical cabling). This may lead to degradation of audio quality.
• When setting up the system up outdoors, be sure to protect it
against rain.
• Care should be taken so that objects do not fall and liquid is not
spilled onto the enclosure. In public event don't let people,
musicians, technicians or anyone put glasses, cups, ashtrays or
cigarettes on the enclosure.
• Always leave the protective grid mounted on the enclosure.
• Use a soft brush or a jet of air to clean the enclosure. Do not use
alcohol, solvents or detergents.
• Take care of your connector cables. Make sure that they are not
damaged, knotted or twisted.
• Do not force connectors and controls.
• Make sure the mains power switch is off ('0') before starting any
connection.
• As long as it is plugged in there can be dangerous electrical
potentials inside the device, so, before undertaking any sort of
maintenance work etc., always make sure it has been unplugged
from the mains socket.
Mains power connection
• Make sure the mains power switch is off ('0').
• Check that mains voltage corresponds to the voltage indicated
on the panel, under the mains socket.
• Use only the factory supplied mains cable or, if a different plug
style is needed, a suitable cable with a ground connection and
marked with the safety approvals valid in the country of use.
All manuals and user guides at all-guides.com
• Leave enough room to get to the mains power socket and the
mains connector on the back panel. As long as it is plugged in there
can be dangerous electrical potentials inside the device, even when
the mains switch is in the '0' (off) position and the power indicator
is off so, before undertaking any sort of maintenance work etc.,
always make sure it has been unplugged from the mains socket
• Always use high quality SHIELDED cables (signal cables) for
connecting external effects, microphones and instruments.
• Always make sure that the channel volumes or the master
volume control are to their lowest settings (counterclockwise)
before plugging or unplugging microphones and instruments.
Every amplified speaker system is characterized by a value of input
sensitivity. The sensitivity is defined as the value of the amplifier's
input signal that will result in maximum power output. An increase
in input signal over that threshold will result, not in increased power,
but in a distortion phenomenon called 'clipping' (output stage
saturation).
In this condition, the speaker will operate improperly.
The diaphragm will exceed it's excursion limits, and the voice coil
will overheat beyond it's thermal limits, resulting in overheating
and premature failure.
The active processors will help in avoiding clipping, by reducing the
amplifier gain and thus the input sensitivity, but this type of protec-
tions may be overridden in very extreme conditions.
What the active processor cannot modify is a signal that is distorted
before getting to the active speaker's input.
The effects of this type of signal are the same as described above.
How to avoid clipping
The simplest way to avoid clipping is to check each level in the
signal's chain. Start from each input channel of the mixer and adjust
the gain control and the equalizer's controls so that the 'peak'
indicator is always off, or blinks only occasionally.
If these levels are exceeded, reduce the channel's input gain.
Connection to the INPUT and to the OUTPUT
Input sensitivity and clipping. How to avoid clipping
MP4
keyboards combo
11
ENGLISH