Montarbo TANK Series Instruction Manual page 10

Important !
Product care and maintenance:
• Never expose the enclosure to heat sources (heaters or other products
that produce heat).
• Never place burning candles or other sources of open flame on top
of the device.
• 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 potentially dangerous electrical
potentials inside the device, so, before undertaking any sort of main-
tenance work etc., always make sure it has been unplugged from the
mains socket.
Power supply 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.
• 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
potentially 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.
Connection to the mixer:
• Always use only heavy gauge, high quality SHIELDED cables
(signal cables).
• Always make sure that the mixer and the powered enclosures
are switched off before connecting them. This will to avoid annoying
noises and signal peaks, which can also be dangerous for the
enclosures themselves.
• Always make sure that the 'Line/mic' switch is up.
10
ENGLISH
2-way, bi-amplifed, active loudspeaker systems
• If the mixer has XLR balanced outputs: use standard balanced
XLR connectors.
• If the mixer has XLR unbalanced outputs: in this case, unless using
a Montarbo mixer, make sure that the XLR outputs on the mixer are
unbalanced to IEC 268 standard: 1 = GND, 2 = HOT, 3 = GND.
• If the mixer has JACK balanced outputs (stereo jacks): it is
possible to use stereo Jack-stereo Jack cables or stereo jack-XLR
adapters, wired according to IEC 268:
pin 1 = ground (sleeve), pin 2 = tip, pin 3 = ring.
• If the mixer has JACK unbalanced outputs (mono jacks):
use suitable Jack-XLR male adapters unbalanced according to IEC 268:
pin 1 = ground, pin 2 = tip, pin 3 = ground
 See page 26.
• Always make sure to use only heavy gauge, high quality SHIELDED
cables. Connect the output of the first system to the input of the
second one (make sure that the 'Line/mic' switch is up) the output of
the second system to the input of the third one and so on.
 See page 27.
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 protections
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 PFL meter will never
(or only occasionally) indicate more than 0dB. In simpler mixers, check
that the 'clip' or 'peak' indicator is always off, or blinks only occasionally.
If these levels are exceeded, reduce the channel's input gain.
Once the desired mix is obtained, adjust the output level so that it never
exceeds the active speaker's or the power amplifier's input sensitivity,
as displayed on the master output VU-meter.
In model TANK101A/TANK121A the input sensitivity is 0dBu.
Parallel connection of two or more systems:
Input sensitivity and clipping.