As far as I know there is only one fuse you can, and is allowed to change, is the one at the mains inn.
You may try the tuning fuses but when you say you have a hard room I would definetely not think of fuse switching first. The difference might not even be noticeable.
If you have a bright room you put up kelims on the wall, have a carpet in front of the speakers etc.
What other components is your stereo made of ?
