Make KMix tray icon control pcm when using mouse wheel
 

I'm using a laptop but the built-in speakers sound like crap so I always use external speakers. Problem is when I mouse over the kmix tray icon and mouse wheel up or down it only alters the master volume, which affects nothing. Basically I want to know if I can change it to control the pcm volume by default. I want to do this cause I hate having to switch over to xmms or open up the mixer window just to change the volume.