My profile picture (and part of my username) is a Celestion Vintage 30 speaker. It is a specific model of guitar amplifier cabinet speaker. While it is used all over music, it is a huge part of the modern sound of metal. IMO its tailored frequency response and its specific nonlinearities at moderately loud volumes are uniquely important in producing a slick and modern-sounding metal guitar tone.

I can't record actual guitar cabinets at the moment because I live with family, but I still use a family of homemade impulse responses that I recorded from my cabinet to play guitar [1]. 9 times out of 10 I solely use an impulse response where the cabinet was loaded with a Vintage 30 (specifically, one of the special ones ripped out of a Mesa Rectifier cabinet). Even when I'm not looking for a "generic modern metal" sound, I typically use a blend of a Vintage 30 and another speaker.

Vintage 30's are not "vintage", they're not 30 inches, they're not 30 watts, they're not from the 1930s...I'm honestly not sure where the name comes from.

[1] What I am saying here is that I simulate the sound of the speaker.