owner
’
s manual |
F15CxA
34
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
maintenance work etc., always make sure it has been unplugged from
the mains socket.
PARALLEL CONNECTION OF TWO OR MORE SySTEMS:
• 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
the output of the second system to the input of the third one and so on.
❯❯❯
See page 54.
Important
INPUT SENSITIVITy AND 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.
