AudioPara Volume and Distortion Solved
I could never hear anybody with the AT&T AudioPara4 file. I performed the registry tweak to switch to the stock AudioPara3 file. You can use Diamond Tweak to accomplish this as well with the 100db European Limit tweak. This improved the volume but distorted the speakerphone at the higher levels.
For those not using Diamond Tweak the registry entry needing to be changed is HKLM\Drivers\BuiltIn\WaveDev\AcousticFile. The stock value is \windows\AudioPara4-xxxxxx.csv. The x’s vary depending on the provider. You need to change this to \windows\AudioPara3.csv.
After trying a couple AudioPara3 files I decided to tweak the stock AudioPara3 ROM file. The files I tried didn’t tweak the levels proportionally and/or didn’t solve the issue. I’ve been having problems with the earpiece not being loud enough and the speakerphone distorting the call. When switching between speakerphone and the earpiece I would have to adjust the volume.
In my tweaked file I modified only the earpiece and speakerphone volumes. There are 5 volume levels for each.
The volume on the speakerphone was the same for levels 3, 4, and 5. What they did was increase the gain each level which caused clipping of the audio. What I did was shift everything up two levels and added two proportionally quieter levels to the bottom. This give none to slight clipping at the highest volume depending on the caller.
For the earpiece I shifted everything down a level and added a proportionally increased 5th volume level. This provided the additional volume I needed without clipping.
Now I can switch between the earpiece and speakerphone without having to adjust the volume level.
Make sure to backup your old AudioPara3.csv file. You will need to use Total Commander to copy the file to the \Windows directory. Afterwards soft-reset and enjoy.
Thanks for the tweaked file. It definitely works. Is it possible you can help tweak the earpiece even more? I really like it when I can hear voices nice and loud.