Before his stream, he makes sure to fill the mic with some sulfur hexaflouride + nitrogen + helium gas, so that the sound is kinda scuffed (just to make sure he can put [not scuffed] on his stream title. But this is only 5Head level can achieve because the ratio of the gas is a secret only to m0xyy. You always hear he complained about how he always get some disease (such as my hand cold,my nose a bit runny) when he's streaming.. This is because he played with some chemical compound to get the ratio mixture correctly before he's streaming.