I have no idea but I would not buy them just based on thier name.
I know the world is running out of not yet copyrighted labels but "Fidelio" ?? Really ???

I know it's the name of an opera, can't remember who's, but I just can't picture myself saying something like...

"I love to come home, kick back and pump up my Fidelio."
"Put Fidelios on your head and and enjoy the soothing realism that only a pair of Fidelios can provide."

With great power comes Awesome irresponsibility.