Chugga-chugga-chugga-chugga. 73% of metal guitar players light their guitar strings on fire due to their lightning fast guitar playing. I just made that up, but that doesn't take away the fact that some of the heavy metal music today is incredibly fast. With such lightning speeds there also must be a different way of thinking when it comes to mixing said music. There are a few different things to think about when mixing metal music as opposed to any other genre, and most of it has to do with keeping up and managing the speed of their instruments.
Kick Drum Click
You know those driving 200BPM metal mixes with the screaming metal singer and pulverizing metal riffs? Yeah that one. What makes those mixes so effective and driving is the sound of the kick drum. The typical kick drum in metal is played at virtuosic speeds. The fact that some drummers can move their feet that fast absolutely astounds me sometimes. Seriously, it's like a superpower.
But the thing about the sound of the kick drum is no the bass part of the kick, but the click of the beater. By EQing the beater at around 3–4 kHz with a big boost we get that signature click that's so important to a metal mix. So next time you're trying to get that metal sound for a specific mix, start with the beater on the bass drum and go from there.
The Wall of Guitar
Heavy Metal music is nothing without the extreme, distorted guitars. Guitar riffs are the backbone of any metal song and being able to create a full, ear-piercing wall of guitar in a metal mix is very important. Double tracking, panning guitars in stereo and using A.D.T are all important aspects of creating that wall of sound aspect of a metal mix. While a lead guitar might be panned off to one side and right out front in the mix, the rhythm guitars are spread all over the stereo spectrum.
The Importance of Clarity
Take into consideration the incredibly distorted, but fast nature of a metal song. You are working with distorted guitars, pile driving drums and chugging bass guitars so it can quickly get messy and cluttered if you don't take care of it. Obviously, perfectly played instrument parts are a must, and something that should have been taken care of during the recording phase. So if you have really well played and locked guitar, drum and bass parts try to stay clear of ruining it while mixing. Too much reverb on guitars will quickly destroy a clear rock riff.
Due to the nature and speed of the guitar and bass players you want the guitars almost dry in order to keep them as clear as possible. There's nothing worse than too much reverb on a fast guitar part, trust me. Try to keep every element of the mix as clear as possible. That doesn't only mean being careful with reverb, but with EQ and placement as well.
I particularly enjoy heavy metal when they have a singer that sings melodies. I'm not a big fan of screaming, although I do like when they add that into their melodies.
But my pet peeves are metal mixes with boxy sounding kick drums, thin and toppy guitar sounds and too much reverb muddying up the mix. I want metal to be clear, and in your face, and by following these three rules here above you can be well on your way to one of them.