[cm12-cm14] [urushi] Too low sensitivity of microphone at video/voice recordings or voip calls

[Bugchecker2]

Video or audio recordings have a very low audio level. (internet calls should also be too silent, I suppose)
Please note: This problem does NOT appear at cellular calls. The sound level is fine here!

I could imagine that a fix of this problem would be a simple modification at a systems settings file, wouldn't it?
Please let me know if you could reproduce this and if/how I could probably modify this by myself also. Thank you.

PS: This problem once was reported here for cm11 at #1110 or #971 already.. But obviously it was not fixed yet, was it?

[Bugchecker2]

Tested with the following ROMs:

• cm-12.1-20160216-UNOFFICIAL-LegacyXperia-urushi.zip
• cm-13.0-20161109-UNOFFICIAL-LegacyXperia-urushi.zip
• lineage-14.1-20170514-UNOFFICIAL-LegacyXperia-urushi.zip