Most "loud speaker" mods edit the "<path name="speaker">" however it seems commented out in LG's file, and there is a different section:
Code:
<!-- Start LGE Speaker For TAS2552 AMP -->
<path name="speaker">
<ctl name="Speaker Driver Playback Volume" value="9" />
</path>
I'm pretty sure that lowering this value, would increase the sound. I set it to 24 and speaker is quiter when pressing volume up. I then set it to 5 and it was quite louder. Searching about the amp, it seems that The minimum volume level for the TAS2552 (control register value 0x00) is -7dB.
For the other values, I just changed all "RX1 Digital Volume" and "RX2 Digital Volume" to 92, instead of the 80/81/84 I found throughout the file. Just need to work on the external speaker now.