User manual

Personal PA

DSP FM Wideband Transmitter

BALANCED LINE USING 1/4" CONNECTOR

IN PHASE

A106

UNBALANCED LINE USING 1/4" CONNECTOR

A107

4.7 K

SOURCE A

SOURCE B

CONNECTING TO A MULTI-CHANNEL OR STEREO SOURCE

A109

BALANCED LINE USING 3–PIN CONNECTOR

IN PHASE

1 2

3 PIN CONNECTOR

A108

IN PHASE

FROM MICROPHONE

1 2

3 PIN CONNECTOR

LOW IMPEDANCE MICROPHONE

A104

UNBALANCED LINE USING 3–PIN CONNECTOR

1 2

3 PIN CONNECTOR

A105

Figure 3: Audio Source Connectors

Multi–Channel Sources

By constructing a simple resistive mixer, stereo (or 3 channel) sources can be connected to the T45. Additional channels can be

accommodated by adding a resistor for each source. Necessary resistors can be obtained from Williams Sound (Part Number

RFC 472) or from any local electronics parts supplier. See Figure 3.

Selecting an Audio source Appropriate for Hearing Impaired Listeners

If the T45 is going to be used specically for the accommodation of hearing impaired listeners, we recommend following these

general guidelines:

The PPA T45 transmits audio with excellent delity. Therefore, the audio source signal should be of the highest audio quality and

not subject to a compressor, limiter, reverberation, or other signal processing equipment. The T45 has a very effective DSP audio

processor. If compression is desired in the audio, refer to the “Compression” section under “Audio Settings - 1a. Audio Presets”

for available settings. Excessive compression is not helpful to the hearing impaired and can contribute to excessive noise in the

receiver outputs.

The T45 audio source signal is usually connected to a mixer’s “line output” signal which is behind the mixer’s parametric equalizers

but ahead of any equalization used for house loudspeakers.

If audio delay is available for use in large auditoriums, it’s usually best to use it. Because radio signals travel faster than sound,

delaying the transmitted audio so that an average listener (in the middle of the listening area) hears the transmitted audio a few

milliseconds after audio from the main sound reinforcement system speaker is helpful. This will also help audience members who

lip read.