This video, which takes its audio from a 2007 interview, takes a crack at defining it.
So, a dubstep or grime is kinda like this ultra slow, ultra dirty spawn of hip hop, but it’s almost at a breakbeat speed, but it’s at a halftime breakbeat speed. So it feels, like, abnormally slow, and just gives this really heavy feel.
Since the evolution of music has slowed since, say, the early 1980s, I thought it would be a long time before a popular genre of music came along that seemed, to my old ears, to be noisy garbage…but then dubstep came along. Industrial, happy hardcore, metal, punk, glitch, and even drum & bass I can appreciate, but dubstep makes me want to yell at children to get off lawns. And I actually like that door stopper noise!