There are six basic types of loop layout for a hearing loop system which can be selected based on its intended function. See below.
What do these pictures mean?
Ampetronic colour plots show the distribution of magnetic field around a loop system, from the side or from above. Black is -40dB below the target field strength, effectively background noise only. Green areas meet the target field strength, white exceeds it. The plots give a good indication of how well a loop will meet the requirements for your application.
Overspill (counter) loop
- One to one communications
- Counters, reception desks, intercoms etc.
- 1 small amplifier
Perimeter loop
- Area coverage, spaces up to 25m wide with no metal loss
- Area coverage, spaces up to 2-6m with metal loss (depends on level)
- Spill allowed up to 4x width away
- 1 loop amplifier required
Single array
- Areas with metal loss but wider than 2-6m maximum
- Only for fixed seating areas, e.g. theatre, classroom
- 1 loop amplifier required
Cancellation loop
- Areas suitable for a perimeter loop where spill control is required on one side only
- Adjacent classrooms etc.
- 1 loop amplifier required
Loss array loop
- Large areas with metal loss
- Areas in excess of 25m wide
- Balconies in theatres
Ultra low spill array
- Adjacent rooms
- Confidentiality
- Nearby interfering systems
- Large areas with metal loss / in excess of 25m wide
