Fuses - Why do same size fuses sound different?

Because of recent reviews on fuses and some manufacturers using some fuses to voice their products, I am embarking on a fact finding mission of why some sound better than others.
Most electronic fuses have nickel plated brass caps with glass or ceramic tubes but vary in sound despite that. I have not been able to find any info on the construction of the elements themselves, is this where the variability in sound stem from?
So far I have compared a set of Cooper-Bussman Ceramic, Radioshack Ceramic, and Littlefuse Glass 10 Amp fuses on my amp. They all sound very different, the Radioshack is by far the worst of the group, its imaging is diffuse, timbres sound off, and it lacked tranparency and extension relative to the others. The Littlefuse have better focus than the Radioshacks, timbres are more accurate and it was more transparent, however, it was extremely bright and etched up top. The Bussmans sounded very good compared to the others, everything fell in place with this fuse, it had very focused images with added weight and detail, timbres were true, and it was the most transparent and relaxed of the group. It had very good dimensionality and musicality, but only when oriented in one direction only.
The moral of this story is that I hope all manufacturers spend the time researching fuses when they use them in their products, otherwise we have to start "fuse rolling" to get the best sound. The good thing about fuses is that they don't cost much.