Not able to control the volume in my music player ?

hello friends,
I have some problem in controlling sound in my music player i used floatcontrol in order to control the volume check this.

FloatControl volume = (FloatControl) c.getControl(FloatControl.Type.MASTER_GAIN);
volume.setValue(-20.63f);

But still i am not able to control the volume.I used sound.sampled package.
Can anyone have idea hoe to fix this issue.