Default Xperia T increase headset volume?

Hi I would like to increase the headset volume on my phone it is far to quiet when listening to music in my car via the audio jack, I used to have a galaxy s i9000 and I used the voodoo amp app that turned up the gain from -10 to +2 and it sounded incredible in the car but my Sony outputs at a much lower volume and sounds pants in comparison!

I've tried a lot of volume boost apps in play store and I've tried flashing sound mods like v4a and zeroinfinitys volume boost and superloud but nothing makes any difference at all!

And I'm stuck with a bootloader unlock allowed : no phone so unable to install custom kernels

Any help to turn up the volume in some way would be greatly appreciated......

Thanks in advance