Raymond Yau wrote:
Do the automatic gain has any side effect when it normalise the volume?
I am unsure of how to go about testing that, 'alsamixer' does not appear to allow me to modify automatic gain.
Do you mean the sound card does not has 7248 steps?
I am not familiar with how to properly check, however dbverify indicates 'Element volume range is 0..151 (-28.37..-0.06 dB).'
Instructions for dbmeasure on the wiki indicates the need for a Line In, the sound card only provides Line Out and Mic In. Will it automatically make use of 'Mic In' if 'Line In' is absent? Or do I even need to use it?
You need to find out the value of c->res As you complain dB range -28.37 to -0.06 are not correct
Quick testing done with dbverify: http://ix.io/eyi
You need to calibrate the dB range
Volume Steps <=3 are mute while volume step 4 is audible, based on dbverify testing. This 'seems' to indicate that the minimum volume is somewhere between -27.81 dB to -27.63 dB?
Additional info logs: Output of 'amixer -c2 contents': http://ix.io/eyq Alsa info script output: http://ix.io/eyn