bi-amped, active loudspeaker systems
2 A
8
2 A
4
-
2 A
2
-
Input sensitivity and clipping. How to avoid clip-
ping
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 models W28As, W24As and W22As the input sensitivity is 0dB.
13
ENGLISH
Important !
Hanging the speakers. Tips and warnings.
W28As - W24As
Both sides of their cabinet embody a slide guide for standard anchor
ring to allow the loudspeaker suspension. On the rear side there are
two recessed rings allowing tilt adjustment.
W22As
- This loudspeaker system is equipped with M10 threaded
fittings to accommodate accessories for suspensions of the enclosures.
The first thing to do is decide which of the anchoring points will be
used for suspension. Once the anchoring points have been determined,
remove the dummy screws and replace them with M10 eye bolts.
ATTENTION: whenever the eye bolts are removed you must be sure
to replace them with the dummy screws.
W28As - W24As - W22As
Please bear in mind that all hanging installation jobs are carried
out under the sole responsibility of the person doing the actual
work and must be done in full compliance with all the applicable
safety rules and regulations. We do not attempt to provide
detailed guidelines for all the potential ways in which these
extremely flexible systems can be installed, but do want to
remind you that to ensure a safe installation, it is necessary
to adhere to the following:
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
- Never depend on only one means of suspension for hanging
speakers (for example one chain); always use at least two of
them and make sure they are sufficiently strong. So, if one fails
the other will sustain the load.
3
- Never hook a speaker to the one above.
Each speaker must be individually hooked to the supports.
4
- 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, the
wind in case of outdoor installations).
