Wilson doesn't use Fuses because they degrade sound quality. The drivers are however protected and customizable with replaceable resisters in the head unit. If you remove the panel behind the head unit with allen wrenches you will find two binding posts with a heatsink (aluminum plate) with two resister packs (they are extremely high quality resisters custom sourced by Wilson so contact your wilson dealer) If you see any solder coming out or the solder has turned brown on the input into the resisters you probably have damaged them, you dealer can check them with a volt meter to see if they are up to spec or degraded.
The Cool things about this design is you could have amplifier melt down and not damage your drivers...plus you can change the tonal characteristics with different values by telling Wilson what you like and down like about the sound.