Difference between revisions of "How are measured Input Peak Levels"

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=Input Peak Level=
=Input Peak Level=


The measurement of the input audio levels to the IPAM based devices (Annuncicom, Instreamer and Exstreamer1000) is provided by the A/D Converter Quasi-Peak Detector Readout.
The measurement of the input audio levels to the IPAM 100 based devices (Annuncicom, Instreamer and Exstreamer1000) is provided by the A/D Converter Quasi-Peak Detector Readout.
In some application FW the value is provided as raw value while in other is displayed as dBFS. The following conversion can be applied.  
In some application Firmware (e.g. Instreamer) the reading is displayed as raw value while in other is displayed as dBFS. The following conversion can be applied.  


The value range is from 0..32767 (32767 is full scale) linear, so referring to full scale 7FFFhex (32767) is 0dBFS.  
The value range is from 0..32767 (32767 is full scale) linear, so referring to full scale 7FFFhex (32767) is 0dBFS.  
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NOTE: the measurement is performed at different time (10-20 msec) for left and right channel thus giving different result even if same audio values are applied on both.
NOTE: the measurement is performed at different time (10-20 msec) for left and right channel thus giving different result even if same audio values are applied on both.
Same values and considerations apply to the Output Peak Level.

Revision as of 13:38, 19 August 2009

Input Peak Level

The measurement of the input audio levels to the IPAM 100 based devices (Annuncicom, Instreamer and Exstreamer1000) is provided by the A/D Converter Quasi-Peak Detector Readout. In some application Firmware (e.g. Instreamer) the reading is displayed as raw value while in other is displayed as dBFS. The following conversion can be applied.

The value range is from 0..32767 (32767 is full scale) linear, so referring to full scale 7FFFhex (32767) is 0dBFS.

0000   -  0% 
2000   -  25%  (-12dBFS) 
4000   -  50%  (-6dBFS) 
7FFF   - 100%  ( 0dBFS)


NOTE: the measurement is performed at different time (10-20 msec) for left and right channel thus giving different result even if same audio values are applied on both.

Same values and considerations apply to the Output Peak Level.