Montarbo W440A Instruction Manual page 13

W440A
active, processor controlled, bi-amped speaker system
Important !
Power supply connection
• Make sure the mains power switch is off ('0').
• Check that mains voltage corresponds to the voltage indicated on
the panel.
• 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
• Always make sure that the 'Line/mic' switch is up.
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 'connectors', 'connections' and 'applications' at pages
36, 37, 38, 39 and 40.
• 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 shall to avoid annoying noises and signal peaks, which can
also be dangerous for the enclosures themselves.
Parallel connection of two or more systems
Use male-female XLR 3 pin balanced extension cables.
Connect the first W440's LINK OUT to the second's LINK IN, the
second's LINK OUT to the third LINK IN, and so on.
☛ See 'connections' at page 37
14
ENGLISH
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 W440A the input sensitivity is 0dB.
Hanging the speakers. Tips and warnings
The W440A speaker features 6 fly points built into the cabinet
(patented) for easily hanging it without using special or additional
accessories. The position of the 6 fly points allows for great
flexibility in terms of speaker configuration.
☛ See examples at page 41.
In order to guarantee a safe and secure installation, observe the
following guidelines:
1 - When hanging the speakers, use only means of suspension
(in accordance with the safety regulation valid in the country
of use) having a carrying capacity rated and guaranteed by
the manufacturer.
2 - Avoid knots. Use cables with pre-made eyelets instead.
3 - Never depend on only one means of suspension for
hanging speakers (for example, one cable, passing through
several fly points to connect two speakers); always use at
least two of them and make sure they are sufficiently strong.
So, if one fails the other will sustain the load.
4 - Never hang more than three speakers together in a cluster
(each speaker is designed to support up to two other speakers).
5 - Always make sure that the truss structure intended to
support the speakers is sturdy enough to hold their weight,
even under stressful, adverse conditions.
Always consider the effect of additional loads (for example,
wind in case of outdoor installations).