Are these considered extreme metal by you?

What's the classic definition of extreme metal? Death, black, and doom? I would say pretty much all black metal and death metal falls under this (so yes, death-doom and tech death are very much extreme metal), but I wouldn't call all doom extreme. A lot of the earlier doom bands were really just heavy metal with slower riffs. But the doom metal that gets played at EXTREME VOLUME like Sleep? Absolutely extreme. And there's no way I could play sludge metal like Acid Bath around the normies and expect them to like it.