Soft dB Opus Suite SLM & 3Vib Module - Manual (Page 59)

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8.5 Audio Setup
Notice: In the SLM&3Vib module, only the SLM input (input #1) is supported for the audio recording.
Do not take into account any reference to input 2, 3 and 4 in this section.
The audio recordings are useful to identify the source of the noise that was measured. Recordings
can be done on a level trigger and/or periodically.
Audio Format
The file format of the audio recordings.
- .mp3 file, 16-bit & 24 kHz sampling rate compressed to 32 kbps
- .wav file, 16-bit, 24 kHz sampling rate (10 kHz usable bandwidth)
- .wav file, 16-bit, 48 kHz sampling rate (20 kHz usable bandwidth)
- .wav file, 32-bit, 24 kHz sampling rate (10 kHz usable bandwidth)
- .wav file, 32-bit, 48 kHz sampling rate (20 kHz usable bandwidth)
As the Kbps (kilobits per seconds) rate indicates, the MP3 format is
interesting since the file size is 12 times smaller than its Wave file
equivalent. However, artefacts resulting from the compression may
be perceptible.
When using MP3 compression, the maximum file duration is 30 sec.
Also the Record Enable mode ON and On Multi-Trig are disabled.
The gain is applied on the audio signal before recording to the file.
- No gain: for very high level or to avoid numeric saturation
- 20 dB gain: for better listening of mid-range levels (around 70 dB)
- 40 dB gain: for better listening of low levels (lower than 70 dB)
This option is useful to facilitate the listening of files that the levels
are low. Such files are otherwise almost impossible to heard in
common audio players.
Applying a gain exposes the audio signal to numerical saturations.