00042762.DOC, Version 1.0
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Installing and orienting the speaker system
When installing the speaker system on e.g. a stage, microphones and turntables should always be located
behind the speaker systems. In this way, you can avoid dangerous and unpleasant feedbacks. If you cannot
install the speaker systems this way, the microphones and turntables should be located as far away as
possible from the speaker systems. When using the speaker system as monitor system make sure to avoid
feedbacks.
The speaker systems of a PA system are normally located left and right to the stage. Do not install the
speaker systems on the stage, but rather on appropriate tables or platforms in front of the stage.
In order to produce a clear sound, the speaker systems should be installed in a way that they throw the
sound over the audience's heads. A full-range speaker system should be installed at listeners' eye level.
Please refer to the safety instructions under Installation.
Loudspeaker combinations need to be installed bass-middle-high (from bottom to top). Make sure that the
membranes of all speakers are in one line vertically and horizontally. Only in this way all frequency ranges
are produced at the same time and without any time or phase delays.
Always install the speaker systems in a way that a minimum distance of three meters to the audience is kept.
This is the only way to avoid hearing damage for unreasonable listeners. Block the area in front of the
speaker systems with appropriate means.
Avoiding feedbacks
One of the most frequent problems when operating speaker systems are feedbacks. They can be recognized
by howling and growling loudspeakers. Feedbacks are created then a signal is recorded by a microphone,
amplified, played back by a loudspeaker and then again recorded by the microphone.
The prerequisite for feedback is that the played back signal is louder than the original signal. A feedback
never cover the whole frequency range but only one overboosted frequency.
Make sure that you install especially the monitor-speakers so far away from the microphone that another
recording of the microphone signal is impossible.
Extreme levels like feedbacks, bass hum or the beats of a dropping microphone can destroy the
loudspeakers within very short time and produce immediate hearing damage. Such extreme levels must be
avoided at any rate. We recommend to use appropriate equalizers and compressors/limiters.
Stacking
Speaker systems may only be installed on top of other speaker systems if the systems are protected against
slipping and flipping over (e.g. via appropriate clamping belts).
