Increase device volume output (avoiding rooting / unlocking bootloader if possible)

[chemeleon]

Hi, I want to increase the very low default volume of the headphone jack on the Xperia XA2. I'm using AIMP which has a built-in EQ and preamp which works well but leads to high distortion (these headphones can handle a lot more without distortion).

On other devices / custom ROMs there is usually a file in /system/etc/ such as mixer_gains.xml, mixer_paths.xml or other configuration file which can be edited to increase the volume output from the hardware with (little to) no distortion. With the latest firmware 50.1.A.10.40, I've explored this folder with a system file explorer and most of the obvious choices aren't there, there doesn't seem to be any file which I could modify to increase the volume.

(I will mention there are a lot of files in /system/*vendor*/etc/ which appear to be of the correct format, but I don't know if any of these are actually used by the system).

I don't want to use a software solution (app from Play Store, etc) since these seem to use an algorithm to increase the gain in software leading to high levels of distortion. I haven't unlocked my bootloader / rooted since there's no guarantee that I'll be able to increase the volume anyway. Has anybody has success increasing the volume on this or a similar device?

 

[chemeleon]

Ok, I couldn't stand it any longer so I unlocked the bootloader and rooted.

Since I couldn't figure out exactly where wired headphones were referenced in the mixer_paths*.xml in /vendor/etc/, using FX file explorer I copied them to a folder and with Notepad++ on my PC replaced each instance of the default volume in all the files (84) with a higher value (96), before copying them back into /vendor/etc/.

After a reboot... system volume (and headphone volume) now at a healthy* level

If anybody wants me to upload a zip of the modified files, you could copy them into /vendor/etc/ using an appropriate file manager (provided you have unlocked the bootloader and are rooted).

 

[chemeleon]

After a dozen reboots or so, I found the values referencing wired headphone volume.

In /vendor/etc/, the file mixer_paths_mtp.xml (lines 313, 314):
<ctl name="RX1 Digital Volume" value="84" />
<ctl name="RX2 Digital Volume" value="84" />
These lines can be modified to increase / decrease the wired headphone volume. I've increased them to 100 in my setup.
The following lines (RX3 RX4 and/or RX5) appear to modify the volume of the phone speaker.
I've attached a modified mixer_paths_mtp.xml which you can copy to /vendor/etc/, although it may be easier to simply modify the relevant lines in a root enabled text editor on your phone.

Requires a reboot to take effect.

This would be the first thing I look for after buying a new phone. I hope it helps somebody. Thank you

 

[jimmygumble]

Great stuff.
Quick question. Do you live within the EU (I do). My phone is also a bit quiet.

Would be interesting to compare values from phones from inside and outside the EU with the enforced volume limits

 

[chemeleon]

Certainly would be interesting, and that's a potential avenue for increasing the volume without rooting (though I know very little about how Sony distributes their firmware). Yeah, in the EU and I had heard (barely, haha) that there were volume limits so guessed that may have something to do with it.

 

[Meloferz]

Great stuff.
Quick question. Do you live within the EU (I do). My phone is also a bit quiet.

Would be interesting to compare values from phones from inside and outside the EU with the enforced volume limits

Using a Xperia XA2 bought from USA, and flashed the GEL Customized version (Latin American version), and values are the same... All RX Digital Volume are limited to 84.