when i play at a relativlty loud volume on the clean channel of my RKII i get a noticable speaker buzz that totaly kills my sound. bad speaker mabye? or could it be something else?
You gotta get your ear in thar and determine if it is the speaker or something else. Find a note that really sets it off and use your hand to dampen things in a process of elimination, including the speaker/frame. Could be loose speaker screws, could be the chassis, etc.
Or just plug in to an external cab, use the same settings, play the same notes, and see if you still get the same noise.
The speaker doesn't have to be mounted in a cab at all, it will still make sound. You could take it out of the cab and wire it up and play thru it, just to see if it makes the offending noise without the cab.