IP audio Gain adjustment

(New from DSP SW 01.11 / AMCD 10.31)

Audio levels and gain on AlphaCom IP audio connections may be changed using NVRAM programming. Defaults has been set, so that normal usage should work without any changes.

Background

Normal audio is encoded in AlphaCom internal digital audio format (SigmaDelta) with a fairly low level, compared to the max theoretical amplitude of the audio format. A headroom of factor 10 = 20dB is common.

For IP audio connections between AlphaComs, the SigmaDelta audio is converted to a standard format like G.722 or G.711. The gain is 1 = 0dB, in the sense that max SigmaDelta amplitude corresponds to max amplitude on the external format. The audio level on these connection will therefore be quite low.

In the telecom world, the standard audio level is much higher, headroom as small as 3dB is normal.