Think of one of your all-time favorite recordings, right now, then ask yourself: what is it about this particular track that makes me want to hear it over and over again in perpetuity? Is it the sound of the instruments, the way the vocals are mixed or processed, or some other element you can’t quite put your finger on?
Much of the credit for that sonic magic goes to those often unsung heroes of disc-making: recording and mix engineers, as well as their post-production partner the mastering engineer, whose sleight of hand has helped wring every last drop of goodness out of countless song classics.
In general, we at-home types are usually better off outsourcing our mastering needs to a qualified third party, if available (and affordable). That said, here are a few ideas for making a mixed & mastered product that will suffice in the meantime.
In the big leagues, the master is the last stop in the recording cycle, the two-track package having already been preened and plucked from the multitrack by the recording and/or mix/balance engineers. Mastering techniques include making discreet equalization adjustments, using enhancers like compressors and expanders judiciously, while ensuring the entire mix is properly balanced throughout. As one pro once put it, “it’s what makes a record sound like a record.”
With DIY mastering, the idea is to tweak only as needed so that the end product sounds as good as possible. Some strategies might include:
Master limiting: If possible, insert a stereo compressor/limiter into the master output section of your recorder. Not only will this allow you to control the peaks but, by setting a uniform level, provides the “glue” that often gives the whole mix a bit more urgency. When doing so, take care to set the unit’s threshold so that the effect is barely audible—remember, just limiting, no pumping or squashing!
Faster master: Using your recorder’s play/record parameters, try incrementally raising the track speed, around 5-10% tops—in certain cases, just a touch faster can give the final a bit more “sparkle.”
Tone control: You can also make a few minor equalization adjustments to ensure the master mix is well balanced. To prevent any room deficiencies from getting in the way, preview the treated track through different sets of speakers (say, in your car, on your laptop or using earbuds, in addition to your regular mix station).
Speaking of EQ, bear in mind that your mastering tools can only do so much once you’ve made your multitrack reduction—therefore, be sure you’ve got a quality two-track in hand (or ideally several different mixes from which to choose or perhaps comp from) before applying the last coat of wax.
Something we’ve often discussed is using equalization to give each signal a well-defined “path.” For instance, problems often arise when there are several instruments with similar frequencies—when left untreated, bottom-heavy acoustic guitars or piano can leave you with an overly muddy mix, while also making the bass track difficult to hear. To remedy this, start by soloing the suspect tracks, gradually adjusting the EQs so that the frequencies no longer match (in the above example, you’ll probably want to trim more guitar than bass bottom).
Because the rules often change depending on a song’s dynamic range, type of instruments used as well as other factors, in reality there is no “master” approach to mastering—what might work for one set of tracks may be completely inappropriate on another. Regardless, trying a few of these simple tricks can help you avoid having a flaccid final product the next time out.