AUDIOropa PROLOOP LOSplus Mode D'emploi page 21

2.8 Metal loss compensation
You will get a loss of the magnetic field strenght if you have strong reinforcement metal in the floor. Compensate this
loss, use the metal loss compensation control (6) on the front side of the loop amplifier. Please follow the steps below
to set the metal loss compensation:
1. Turn the Metal loss compensation control to the left position.
2. Connect headphones to the headphone socket of the amplifier and listen to the audio signal.
3. Use an inductive loop receiver and the same headphones to listen to the audio signals of the inductive loop.
4. Turn the Metal loss compensation control to adjust the tone of the audio signal.
3. Setting up a LOS loop system with PROLOOP LOSplus
3.1 Why LOS?
Standard induction loop systems create a magnetic field that usually goes beyond the »key supply area«. This
horizontal and vertical »overspill« can still be audible in areas up to three or four times outside the actual induction
loop, which tends to limit the applications for which this technology can be used. Low-overspill systems (LOS),
designed and configured by qualified experts, significantly reduce overspill and make it possible to use induction
loop systems in directly adjacent rooms.
The PROLOOP LOSplus is a complete system for the operation of low-overspill systems. It includes all the elec-
tronics required in a single housing.
3.2 LOS induction loops
The optimal designs and configurations are always dependent on the venue details, i.e. the floor plans and the
sizes of the rooms serviced, the number of internal induction loops and the demands made on low overspill.
To determine the corresponding values for the »tailored« low-overspill layout and the optimal level adjustments
in each case, it is necessary to use complicated calculation and installation methods. That's why we recommend
that you use the services provided by AUDIOropa. We support architects, technicians and installation experts
qualified in the planning of LOS installations.
3.3 Installation of the induction loop
To use a LOS system, the induction loop must be installed in a special way. In detail, two separate loops are
used (master/slave), which consist of eight-piece segments lined up one after the other. The exact proportions
and the exact number of segments depend on the demands made on low overspill as well as the size of the
room. The smaller the segment, the smaller the overspill will be.
The master loop is laid over the entire area to be serviced. The slave loop is always one segment shorter than the
master loop and doesn't begin until after the first segment half of the master loop. The individual segment lengths
should correspond to the distances between the seating rows.
We recommend using a single-strand cable, e.g. H07V-K or the copper ribbon cable (A-4937-0, 50m role /
A-4948-0, 100m role).
3.4 Advantages of a LOS induction loop design
- No loss of field strength in the centre of the induction loop
- No horizontal overspill
- No signal holes inside the loop
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