Tandberg Data 3000MXP - Manual (Page 87)

4 Administrator Settings
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Place all microphones as far as possible from the loudspeaker. Minimum
loudspeaker-microphone distance should be 2 meters.
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It is recommended to place the microphones between 1 and 2 meters away from the
persons speaking. By using several microphones, the ratio distance loudspeaker-to-
mic/mic-to-speaker can be increased. Increasing this ratio improves the echo
canceller performance.
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Place all microphones as far as possible from noise sources.
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Reduce the volume setting. Ensure that the loudspeaker does not distort the audio.
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The echo canceller tries to estimate the echo path from the speaker system to the
microphones. Moving objects change this path, therefore try to avoid moving objects.
Be especially aware of large objects and objects placed close to either the
microphone or the speaker system as these objects will cause severe changes to the
echo path.
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Avoid putting paper sheets etc. on the microphone.
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Avoid moving the microphone or loudspeaker.
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In the presence of low frequency noise, enable the noise reduction (NR).
4.5.4 Stereo Settings
Stereo Input mode (stereo audio)
If stereo Input mode is activated, audio input 3 and 4 will behave as a stereo input pair. The
VCR Ducking and AGC setting for audio input 4 will in this case apply to both audio input 3
and 4.
If Stereo Input Mode is off, Audio out 2 will be a mix of audio input 3, microphones and the far
end (mono or left+right). If Stereo Input Mode is on, Audio out 2 will be a mix of the
microphones and the far end (mono or left+right).
Note that you are able to receive stereo through Audio out 1 (S/PDIF) independent of this
setting.
4.5.5 Audio Leveling (AGC)
On Select On to allow automatic adjustments (Automatic Gain Control) of audio
levels. When On, the AGC maintains the audio signal level at a fixed value by
attenuating strong signals and amplifying weak signals. Very weak signals, i.e.
noise alone, will not be amplified.
Off Audio leveling is not activated.
Note that to ensure correct behavior of the AGC, it is crucial that the levels on the input
connectors are adjusted correctly using the audio input level settings. The AGC will not
compensate for severe maladjustment of input levels.
When applying a weak signal in the presence of strong background noise, the AGC might
amplify the background noise as well as the signal. Therefore, in noisy environments, it is
advisable to turn the AGC off.