Master Audio
Mastering audio can be a complex process. Professional engineers spend years perfecting techniques and chains of effects. Lots of practice and a refined ear can lead to impressive results when rendering a mastered track from a raw track. Many people use software to master audio, and software is easier to work with than analog gear if you're just starting out. Here are some steps to get started on mastering audio.
Steps
- Buy a high-quality set of speakers or headphones. To master audio, you must be able to accurately hear what is playing back. Studio monitors or headphones can be expensive, but they are essential tools.
- Mix down a session to a single stereo track. "Mixing down" means taking all the tracks you've recorded and exporting them, or mixing them, to a single stereo track.
- It is better to apply effects using a single stereo track than use the master bus on an entire session. The "master bus" is the master volume channel for all of the tracks you record. Some engineers decide to apply mastering effects to this channel, but it is not advisable for novices
- Maintain the highest bit-rate possible. If you recorded at the recommended 32-bit rate, maintain this quality. You can convert the file to the CD-standard 16-bit rate once you've applied your effects and are satisfied with the track.
- Normalize the track. Normalizing brings the highest amplitude to the maximum volume you have set. Many people set their peak at -0.2 dB, which means the waveform will be raised to a maximum of 0.2 decibels under zero.
- Apply a basic equalization. Depending on the quality of the initial mix you don't want to make a lot of drastic changes here. Experiment until you've achieved the desired sound.
- Add more bass and lower mid-range frequencies to create body. Bring up the upper harmonics to produce more clarity. For example, cutting frequencies around 250 Hz will add some clarity to the sound; and boosting around 1kHz will make the vocals appear more present.
- Apply compression to gain control over the dynamic range of the audio track. Dynamic range is the amount the song varies from it's lowest volume to it's greatest volume.
- Start with a 2:1 ratio and set the post gain at 0. Make very small tweaks until you achieve the desired effect. You should notice that quieter parts of the song sound louder and clearer, and that louder parts are not as loud.
- Don't make the ratio too high or else you will get a very squashed sound. A squashed sound implies that the audio does not sound open and the subtleties of the piece are lost because every instrument is so close in volume.
- Apply equalization. This is meant to be put in the chain after the compression and is helpful in shaping the tone. You probably won't need much equalization, but you can do some minor shaping to the sound after you apply the dynamic effects of compression.
- Apply reverb to the track. Reverb essentially models room spaces and gives the processed audio track more of a live feel. Reverb will add depth and give the stereo track a warm and complete sound. Add as much or as little as you'd like, depending on the effect you are seeking.
- Apply a limiter. Limiting the audio to a certain dB level will give you more volume. Begin by setting your limiter at -0.2 dB. You should notice a definite increase in volume. To avoid unnatural, unpleasant sounds, do not raise the gain too high.
- Convert your stereo file to 16-bit and 44.1 kHz. You can do this with your audio mastering program, so consult the program instructions for help.
- Burn the track to a CD. When burning your mastered audio track to a CD, set the write speed as low as possible to make sure the quality of audio is as high as possible. Many engineers burn at 1x or 2x. You can then duplicate the burned disk and be assured the sound quality will be replicated.
Tips
- There are many resources on the online, and many books have been written, that outline audio processing techniques in great detail. The mastering process is complex and it helps to keep learning.
