User manual

Safe dynamic range.
In HP mode internal processor provides HP crossover function based on
acoustical responce. This perfectly matches the proper MB SubWoofer model.
This switch configures internal processor to drive SubWoofer in mode based on
acoustical responce at or .
The choice of Crossover Frequency depends on which MB Full Range model is used in combination
with MB 18.0 or MB 12.
The following table provides a general guideline how to combine Full Range and Subwoofer
models:
MB 8.1 (HP mode) - MB12.0 (100Hz mode): crossover frequency 100Hz.
MB 12.1 (HP mode) - MB 18.0 (100Hz mode): crossover frequency 100Hz.
MB 15.2 (HP mode) - MB 18.0 (80Hz mode): crossover frequency 80Hz.
Full Range mode should be chosen when
Loudspeakers (Full Range section) are used without SubWoofer. However HP mode may be also useful
as System-LowCut in specific situations. This results in acoustical responce shaped as
4th-order HP filter tunded at stated frequency (100Hz or 80Hz, depending on the model). On the other
side Full Range mode could be usefully operated by experienced engineers even when SubWoofer is
used, especially on MB 15.2, after phase relations amoung the different sources has been properly
analysed and tuned.
Follow these steps:
Make sure that all mains cables are disconnected in the reinforcement system.
Connect all audio cables respecting wiring schemes provided for operated equipment.
Provide proper configuration for Operation Mode Switches on all of Loudspeakers.
Switch on first other units (mixer, outboard effects, etc), then connect MB Loudspeakers to mains,
otherwise cracking noise could be expected which could potentially damage Loudspeakers.
After 5 seconds mute, the system is ready to work
Switch off sequence has to be reversed: first MB Loudspekaer, then other units.
For most applications driving MB SubWoofers and MB Loudspeakers (Full Range section) with the
same signal provides adequate balance. Driving SubWoofers with two input signals (Left and Right
inputs) increases the level (up to +6dB when signals are identical and in-phase). When a specific
different balance is needed, then an external level control is advised (e.g. Mono or Matrix output from
FOH EQ or Mixing Consolle).
l. In
this situation additional loudspeaker systems should be used, to provide the desired SPL.
Model MB 18.0 and MB 12.0
Crossover
100Hz 80Hz
-
Linkwitz-Riley 4th-order
Linkwitz-
Riley 4th-order
Linkwitz-Riley
Make sure that no audio signal (or very low level) is at Loudspeakers input, to avoid transients or
unexpected loud sound.
Each transducer inside MB Loudspeakers is provided with independent time-shaped limiter system
that reduces the risk of possible failures due to driver over-excursion and voice coil over-temperature.
This is achieved at the cost of minimum audible dynamics compression.
However a continuously increasing input level has to be avoided, as considerable and audible loss of
dynamics may be expected. In this situation although protected by the limiter, the components
experience a considerable loading (due to reduced crest factor of compressed audio program) which
can significantly shorten their lifespan.
The sound engineer should recognize, when input level is in the mentioned range or higher, that the
audio program from the loudspeaker is highly compressed and turn down the level of input signa
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Operation Mode Switch (General Consideration).
Operating Sequence
Important Operating Notes
Page 8