WELU Assistive Listening System

Equipment setup procedures

Equipment setup and preliminary checks/adjustments are included.

The additional equipment for the Assistive Listening System comprises a special headphone amplifier, one or more transmitters and their associated power supplies/connectors and audio connections to the existing mixer console as outlined here.

It is critical that an adequate signal level is available for the headphones. Therefore, it is important to follow the settings outlined below to ensure the system operates correctly.

Therefore the following adjustments should be checked/made to the controls of the main amplifier, the mixer, headphone amplifier, and transmitter:
The numbers in brackets () below refer to the various controls on the associated diagrams.

MAIN AMPLIFIER

MIXER

mixer

mixer

mixer

For each channel in use:

The objective is to achieve a peak output LEVEL of 0dB (37) with little or no clipping. This can usually be achieved with the above settings, but speaker's voices and other factors will require the settings to be adjusted. If the output LEVEL is correct and the loudspeaker volume is not correct, then the MAIN AMPLIFIER input should be suitably adjusted.

HEADPHONE AMPLIFIER

amp

For each CHANNEL in use:

TRANSMITTER

The recommended headphones have an on/off switch, and an independant volume control. Ensure the “auto-tune” button on the headphones is pressed once after the system is switched on.

If users have older model headphones requiring the channel to be manually selected, it should be set to Channel 1 to match the transmitter.