bi-amped, active loudspeaker system
W18As
5
Important !
Product care and maintenance
• This product has been designed for use in tropical climates and
particularly warm weather conditions.
• Never place burning candles or other sources of open flame on top
of the device.
•
Never expose the enclosure to heat sources (heaters 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.
•
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.
Connection to the mixer
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-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 'connectors' at page
7
.
•
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.
Parallel connection of two or more systems
• Always use only heavy gauge, high quality SHIELDED cables (signal
cables). Connect the LINK OUT socket of the first system to the LINK IN
socket the second system and the LINK OUT of the second system to
the LINK IN of the third, and so on.
See 'connection example' at page
7
.
Input sensitivity and clipping. How to avoid clipping
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 W18As the input sensitivity is 0dB.
