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Extron Electronics VN-Matrix 250 User Guide User Manual

Page 69

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Figure 43.

Audio Bandwidth Tab

Audio output selection (Audio Control panel)

Select the appropriate check boxes to output the received audio stream to the

HDMI

port,

the

Analog

output port, or both. The HDMI output level cannot be controlled and is equal to

the level seen on the encoder device.
The analog audio output level is controlled using

Analog Output Level

. The output level

will be correct if the input level on the encoder has been correctly configured for optimum
signal level.

Return audio configuration (Audio Control panel)

The return audio input must be separately enabled and the level must be manually
configured to achieve an undistorted signal with the optimum signal to noise ratio. The input
level is selected using the

Analog Input Level

setting and is set to a value just larger

than the maximum input value. If this level is unknown, the

Analog Input Measurement

continuously shows the current input level. If the input measurement shows over‑range the
input level should be increased until the over‑range condition clears. If the measurement
is more than 2 dB below the set input value, the input value should be reduced to be 1dB
greater. These measurements must be carried out when the content of input signal is at a
maximum volume and the stream must be connected to a suitable encoder. If the audio is
not being streamed, the measurement shows disabled.
Reverse audio data is always sampled using 16 bits stereo at 48000 Hz. It is then
compressed to the "decimate 2" level resulting in a reverse bandwidth of 784 kbps. It uses
a "best effort" delivery making no effort to obscure dropped packets and not managing the
delay between decoder and encoder.

Decoder audio stream statistics

The audio stream

Statistics operate in the same ways as the video statistics (see

Decoder

video stream statistics

on page 62).

Decoder audio buffer

The decoder audio buffer operates in the same ways as the video buffer (see

Decoder

video buffer

on page 61).

NOTE: The frame delay setting reflects the value that is set in the video buffer and

cannot be adjusted.

VNM 250 • VNM 250 GUI Overview

63