|The Current Thinking ET150 professional audio frequency induction loop amplifier (AFILS) provides assistive hearing coverage up to 200m² (for a rectangular room) or 150m² (for a square shaped room).
- This induction loop amp has 3 XLR inputs; 2 dedicated microphones and one microphone / line input, selectable using a rear panel switch.
- User selectable Phantom Power is also available for the microphone inputs, enabled via a rear panel switch.
- The inputs are individually mixed before passing to the compressor limiter preventing loop overload and compensating for varying microphone use / technique.
- Recessed tamper resistant controls are on the front of the amp along with status indicator LEDs for compression level, output current, loop status and power supply.
- Headphones can be used to monitor the actual loop current. An audio output (post compressor) is provided for recording, with a slave audio in to allow cascading.
- A 'loop OK' output voltage is provided for an external illuminated sign to show correct loop operation.
- The ET150 is 1u (44.5mm) high and a 19" rack mounting kit is available separately.
Choosing the right unit
All In order to remove the "magic" from loop amplifier specification, Current Thinking recommends loop amplifiers are specified thus; by maximum square area and by length of the shortest side. These areas relate to loops fitted at skirting board or ceiling (2.4m) height and provide even loop coverage. For example, the ET150 will cover a square room 12.25m per side (150m2), however the same amplifier will also cover a rectangular room 10m by 20m (200m2).
In this example the ET150 is rated at 150m2 square area and 10m for the shortest side. The shortest side rating is valid for distances up to twice the shortest side, for example the ET450 is rated at 20m shortest side, so the other side of the rectangle can be a maximum of 40m (giving a coverage of 800m2). If the loop is above 2.4m in height, then 20% should be subtracted from the shortest length for every additional metre in height the loop is (to a maximum of 4m).
These values do not take into account additional losses present in some building constructions, if you are in any doubt always lay a temporary loop. It is always wise to allow 20% spare capacity when specifying a loop amplifier, just to cover the unknown element.