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Difference between revisions of "Dynamic Range Compression (DRC)"

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{{AEIS}}
 
{{AEIS}}
'''Dynamic Range Compression (DRC)''' is a feature in the [[:Category:Intercoms and Devices|Zenitel IP devices]]. The DRC function is processing the audio signal, and helps even out the loud and quiet parts. Lower signals will get gain applied, but not more than there is headroom for up to digital full scale.
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'''Dynamic Range Compression (DRC)''' is a feature in the [[:Category:Intercoms and Devices|Zenitel IP devices]]. The DRC is an audio signal processing function that helps even out the loud and quiet parts. Lower signals will get gain applied, but not more than there is headroom for up to [https://en.wikipedia.org/wiki/DBFS digital full scale].
  
For intercom devices and IP Speakers the DRC will have a good effect on regular speech signals, and will normally increase the loudspeaker output noticably. For already maximized signals, such as prerecoorded alarm tones, DRC will have little or no effect.  
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For intercom devices and IP Speakers the DRC will normally have a good effect on regular speech signals, and will often increase the loudspeaker output noticeably. For already maximized signals, such as prerecorded alarm tones, DRC will have little or no effect.  
  
 
{{Note|
 
{{Note|
* ''The DRC function is by '''default disabled'''.''
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* ''The DRC function is by default disabled.''
* ''The DRC is a dynamic digital signal gain adjustment function, and some signal clipping may occur if the DRC is configured to use high gain''.
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* ''The DRC is a dynamic digital signal gain adjustment function, and some signal clipping may occur if the DRC value is set too high. Normally a value of 10dB or less gives a good effect. Even when set to 0dB one will experience increased volume if the input signal is low.''
 
* ''The DRC function works very well in combination with the [[Automatic Volume Control (AVC)]]''.}}
 
* ''The DRC function works very well in combination with the [[Automatic Volume Control (AVC)]]''.}}
  
 
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== Configuring the DRC feature==
 
 
 
 
Acoustic Echo is when you during a call can hear your own voice in return, with more or less volume, and more or less delay. The echo can range from simply annoying to absolutely unbearable, and may result in callers not understanding each other and important information being missed.
 
 
 
The purpose of the AEC feature is to remove this echo. In Zenitel IP Devices the AEC feature is by default active. Zenitel IP intercoms have been calibrated from factory, and the AEC level is by default set to the most suitable value. Hence there is normally no need to alter the default settings.
 
 
 
Some parameters effecting the acoustic echo cancellation:
 
*Loudspeaker volume
 
* Microphone sensitivity
 
*Distance between speaker and microphone
 
*Mechanical design (e.g. vibrations, speaker and mic mounting)
 
*Environment (e.g. reflecting surfaces)
 
 
 
<br>
 
 
 
== Configuring the AEC feature==
 
 
Configuration is done from the Audio Settings menu. First enable '''Advanced Configuration''' mode. Depending on the mode of operations, select:
 
Configuration is done from the Audio Settings menu. First enable '''Advanced Configuration''' mode. Depending on the mode of operations, select:
 
*Edge mode: '''Edge Configuration''' > '''Audio Settings''' > '''Audio signal processing'''
 
*Edge mode: '''Edge Configuration''' > '''Audio Settings''' > '''Audio signal processing'''
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<tr style="rowspan:2;">
 
<tr style="rowspan:2;">
<td style="display: block; vertical-align: bottom;">[[Image:AEC config.png|700px]]</td>
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<td style="display: block; vertical-align: bottom;">[[Image:DRC config.png|700px]]</td>
 
</tr>
 
</tr>
 
<tr>
 
<tr>
<td style='background-color:#efefef;'>'''Acoustic Echo Cancellation''' configuration menu (firmware 7 and later)</td>
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<td style='background-color:#efefef;'>'''Dynamic Range Compression''' configuration menu (firmware 7 and later)</td>
 
</tr>
 
</tr>
 
</table>
 
</table>
  
*'''Enable AEC''': Check the box to enable suppression of echo on the microphone signal. Default enabled. If disabled the loudspeaker and microphone will be open without any audio processing.
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*'''Enable DRC''': Check the box to enable the DRC function.
*'''AEC mode''': Sets the aggressiveness of the echo suppressor. A higher level trades off double-talk performance for increased echo suppression. Available suppression levels:
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*'''DRC gain''': Specifies the maximum gain which will be added to the signal. Note that some signal clipping may occur if the DRC is configured to use high gain.
**'''Low'''
 
**'''Moderate'''
 
**'''High'''
 
**'''Half Duplex'''
 
 
 
With "Half Duplex" the loudspeaker will be muted when speaking into the microphone.
 
 
 
'''High''' or '''Half Duplex''' can be used in noisy or acoustic challenging environments, or in customized stations without optimal acoustic design, where one is experiencing issues with echo, chopping audio or one-way audio.
 
  
{{note|
 
* ''For devices operating in Open Duplex the AEC needs to be enabled. If the '''AEC is disabled''' and the device is used for two-way loud-speaking communication, it is very likely to get [https://en.wikipedia.org/wiki/Audio_feedback acoustic feedback] (aka Larsen effect)''
 
* ''All audio settings can be reset to default values by selecting [[Factory Reset Audio Settings]]''. }}
 
  
 
[[Category: ICX-AlphaCom features]]
 
[[Category: ICX-AlphaCom features]]
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[[Category: IC-EDGE Configuration]]
 
[[Category: IC-EDGE Configuration]]
 
[[Category: AlphaCom features]]
 
[[Category: AlphaCom features]]
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[[Category: Audio Settings and Audio Features]]

Latest revision as of 13:28, 9 November 2023

AEIS.png

Dynamic Range Compression (DRC) is a feature in the Zenitel IP devices. The DRC is an audio signal processing function that helps even out the loud and quiet parts. Lower signals will get gain applied, but not more than there is headroom for up to digital full scale.

For intercom devices and IP Speakers the DRC will normally have a good effect on regular speech signals, and will often increase the loudspeaker output noticeably. For already maximized signals, such as prerecorded alarm tones, DRC will have little or no effect.

Note icon
  • The DRC function is by default disabled.
  • The DRC is a dynamic digital signal gain adjustment function, and some signal clipping may occur if the DRC value is set too high. Normally a value of 10dB or less gives a good effect. Even when set to 0dB one will experience increased volume if the input signal is low.
  • The DRC function works very well in combination with the Automatic Volume Control (AVC).


Configuring the DRC feature

Configuration is done from the Audio Settings menu. First enable Advanced Configuration mode. Depending on the mode of operations, select:

  • Edge mode: Edge Configuration > Audio Settings > Audio signal processing
  • SIP mode: SIP Configuration > Audio Settings > Audio signal processing
  • ICX-AlphaCom mode: Advanced ICX-AlphaCom > Audio Settings > Audio signal processing
DRC config.png
Dynamic Range Compression configuration menu (firmware 7 and later)
  • Enable DRC: Check the box to enable the DRC function.
  • DRC gain: Specifies the maximum gain which will be added to the signal. Note that some signal clipping may occur if the DRC is configured to use high gain.