This article not only gives you my mastering approach for the genre, I also factor in client feedback so your audio masters will make them happy too. But remember, A/B comparison and matching is always your goal. This section assists you in doing that.
How To Master Hard Rock And Heavy Metal
Ratings - I rate each sonic quality on a scale from 1-10 (5 is an average amount). Except for overall loudness, I use my ReplayGain recommended levels.
Clarity (5) The guitars are usually bright and thick, so you're not going to get the same clarity you would from a song with thinner instrumentation.
The vocals should cut through nicely, but most clients in this genre purposely want the vocals under the music a bit because they're usually not very good singers. This is ok if you can understand most of the vocals. If you can't understand 20% or more, the client should fix it. If they refuse, be sure to emphasize you made them aware of a serious vocal problem and they refused to correct it.
You don't want them coming back later and either bad mouthing your mastering, or asking for a refund.
Brightness (8) Metal and hard rock are the brightest of the major genres because of the thick stereo guitars. They're the brightest, but make sure you A/B compare well, not to go too bright. This music is played loud!
The tone of the guitar brightness is very important. You want a nice full bright sound with some bite to it, not thin and tinny bright.
Bass Volume & Boominess (4 or 6 the new hard rock) I don't want the bass too boomy. I do often add some boominess to this genre, but only to thicken up the song if its too thin. I want the bass to be felt and have presence, but just loud enough so you can barely hear it. I never want a ringing boomy bass (like in hip hop). This applies to most hard rock songs.
The exception to this rule is hard rock with the big powerful double kick (the new hard rock). You want to be able to hear and feel this. These songs aren't just about the guitars. The big bass is important too.
Overall Compression (7) These genres are played loud, so I can't have them breaking up. Using the Multi-Band Compressor in the UPPER-MIDS, I always cut the top off.
Even though this is a loud genre that needs compression, if you're working with clients, most of the time rock is compressed very well by whoever mixed it. You can usually tell just by looking at the .wav file. Slight or no compression is required if this is the case.
Stereo Width (7) A nice stereo width is very important for the stereo guitars.
Overall Loudness ReplayGain Number (99-99.5) Metal/hard rock and hip/hop rap are the loudest genres. This recommended volume works well.
For more of my articles on mastering your own songs, check out - Audio Mastering Secrets.