Default [closed] Volume boost?

Hi everyone,

I did multiple researchs but could not find any specific answer for the HTC One.

I converted my HTC One to a full rooted Google Play Edition.
Installed xposed framework and GravityBox (loving the whole package).

My phone streams music via bluetooth APTX to my Hifi amplifier.
Even at maximum, the sound volume isn't high enough and I have to tune up my hifi amp system to the max.
I explored options like Viper Volume Booster but i don't hear any difference.

Is there any mod avaible to boost the volume with Gpe? Using Xposed framework?
Flashing a mod?

Thanks!
K

PS: Found this http://androidcure.com/increase-volume-htc-one/ but seems to be working for custom roms only...

PS2: ok, I finaly found this http://forum.xda-developers.com/show...11163&page=410
shame on me....