Handbook for Sound Engineers

Interpretation and Tour Group Systems 1541

Fig. 41-13. Soundfield FM applications can be in a
classroom, meeting room, training center, or theater.
Studies have shown that boosting the audio levels of
normal voices increases retention by as much as 30%
for the listeners, and can reduce potential for voice
strain and fatigue for the presenter.

Wherever a large PA system is impractical, a Sound-

field FM-type solution is a possible answer. A Listen

Soundfield FM system is an easy way to deliver inter-

ference-free sound to groups of all sizes insuring that all

participants hear the message clearly.

The LR-100 Stationary Receiver/Power Amplifier,

when used with a Listen transmitter, delivers audio for

use in a variety of locations and applications—most

commonly soundfields. The unit has an LCD display

showing channel, lock, and battery level. A security

cover protects auxiliary and receiver volume and trim

controls. It has an adjustable squelch control, balanced

or unbalanced loudspeaker wire output options, and

multiple input options for flexibility. The system is

powered by a 16 Vac/1000 mA power input or a12 Vdc

battery. An antenna can be added for longer range

applications.

The LR-600 is a wireless receiver, two-channel

10 W power amplifier and loudspeaker. The unit is

powered by alkaline or NiMH rechargeable AA

batteries, or a 15 Vac power supply or 12 Vdc, for

15–10 W continuous power output. It has unbalanced

auxiliary input and output ports. The LCD display

shows channel, lock, and battery level.

Figure 41-13. A portable system utilizing FM transmission
for the microphone input. Courtesy of Listen Technologies
Corporation.

DVD

Computer

Microphone

Presenter

Loudspeakers

Participants

Soundfield receiver