What is the right fuse for my speaker?

You can use this nomograph. You see 3 vertical lines: the first is Speaker impedance, in the middle we have the fuse value to find out, the last line symbols the peak power of you speaker (1/4 th of the music power). Draw a line from left to right, starting with your speaker impedance and ending with the peak power of your speaker. Where your line crosses the fuse-line, that's the maximum fuse rate you should use. Use fast fuses. The symbol is F. For powersupplies you use slow fuses. Their symbol is T.

here you can download the graph .