To change initial ringtone to loud instead of soft, go to the following registry

HKEY_CURRENT_USER/CONTROLPANEL/SOUNDCATAGORIES/INCALL
Change INITVOL from 2 to 4 and soft reset the phone.

Alternative solution:

Go to HKCU\ControlPanel\SoundCategories\Ring\AttenuationCategory and change the value to 1 and you are all fixed. No more annoying increasing ringtone. Set it loud and have it loud, set it low and keep it low 
There are 3 values that the AttenuationCategory can be set for. 

0 is no ringtone volume
1 is flat ringtone volume
2 is increasing ringtone volume

REMEMBER TO WAIT 30SECS THEN SOFT RESET.

Note that these 2 methods doesnt work for all handset... still trying to explore the reason behind it...