Fix For Low Microphone Volume On The Samsung Galaxy S II
by Hans Petter Eide
Since I received my Galaxy S II a month ago, people have been complaining that they can barely hear me in calls. I first found out that turning off the noise reduction (by pressing the menu button while in call, and then pressing “Noise Reduction Off”) partially solved the problem, but this naturally also meant that the noise reduction feature was gone.
So I started click around the menus on the phone trying to find a way to fix this. At last it seems that I have found a solution:
- In the phone dialer type in *#*#197328640#*#*
- A menu should now be shown. In the menu, press  AUDIO
- …then  NB (VOICE CALL)
- …then  HANDSET
- …then  VOLUME
- …then SRC SPEECH RX Volume
- …then 5_lvl: 88 (note that you might have another value than 88 on your handset. Write down this value in case you want to revert to it later)
- The window that is now shown should have a line saying “Input?”. To input a new value press the menu button, then “Key Input”. Write 110 as the new value and press “OK“.
- You have now adjusted the microphone volume when noise reduction is disabled, and it is time to do the same when noise reduction is turned on.
- Press the menu button, and then “Back”. Do this four times in total, until you get back to the menu that the text “NB (Voice Call)” in the first row.
- Now, press  HANDSET(2MIC) and repeat steps 4 to 8 listed above.
I have had no complaints about the microphone volume after I completed these instructions. Hopefully it applies to you as well! The only downside with this trick is that it won’t survive a restart of the phone. A tip if you want to be unreachable without turning it off is by setting it in “Airplane Mode”. In this mode the phone barely consume any battery if it is not used.
Disclaimer: Although it is highly unlikely that it should happen, I take no responsibility if these steps should brick your device.