Mastering is the combined science and art of taking a finished mix and tweaking it in ways that can range from adding a professional polish to really taking the mix to a whole new level. Sometimes the before and afters can be quite dramatic and what you thought sounded great before can tend to now seem somewhat flat and lifeless.
As Paul White from Sound on Sound magazine put it, “What many people don’t realize is just how great a difference is made to commercial records at the mastering stage. Prior to mastering, you might be surprised at just how ordinary some mixes sound. ”
The main mastering tools are compression, EQ and limiting and because of this there is something that you need to be very aware of when mastering and that is that these tools will raise the overall apparent volume of the mix and this alone can make the mix suddenly “sound better”. It is important to be able to switch effects in and out in such a way that you don’t get fooled by this artificial improvement caused just by raising the volume.
Obviously it is very important to have an accurate monitoring environment for mastering but also important is the quality of the equipment, whether hardware or software, that you put your mix through when mastering. Many people route their mixes through analog tube hardware to get that added warmth and richness.
Other tools that get used in mastering include exciters, stereo image wideners, software that can increase or decrease the volumes of the center instruments (such as vocals), software to emphasize the transients (great for bringing the drums out in a mix), software to add tube warmth or to simulate tape saturation, sub-bass boosters and even reverbs.
Another very useful mastering tool is the multiband compressor which splits the mix into 4 or more frequency bands from low, via the mids to the highs, and enables you to compress each band separately so that you can tighten up the bass, for instance, without effecting the other elements in the mix. There are also a number of all-in-one mastering software tools that combine many of the above effects into one plugin. I will be reviewing some of these soon.
If you are sending your mix to a mastering engineer make sure that you keep any compression, limiting and EQ of the overall mix to an absolute minimum so that you leave room for the mastering engineer to work his magic. There are often confusions between what exactly is the difference between a compressor and a limiter and I will be clarifying this in another upcoming post.
Also done at the mastering stage are setting the optimum volume levels between tracks as well as the gaps between the tracks.
This post has only scratched the surface of some of the technical aspects of mastering. I plan to expand upon these with more specific uses of mastering tools as well as getting more into the artistic side of mastering in a future post. What have been your experiences with mastering, were you happy with the results?