A guide to post production sound
This article will explore the processes of preparing audio for release, detailing the steps needed in post-production sound. It will explore some of the tools needed for the process, including EQ, compression and limiting, as well as detailing the export options available.
First steps
Whether it's for film, television, radio or music performance, the tools used to polish and improve audio in post-production are the same. Audio engineering is a discipline that combines aesthetic judgements with scientific principles, and as such it's a good idea to have the right tools to start with. Make sure you have your preferred DAW (Digital Audio Workstation) in front of you. Most sound studios and audio schools (as well as college engineering studios) will have a selection of good ones, with Pro Tools being the industry standard. Next, ensure you have your favourite plugins (such as software EQs, compressors and other effects units) installed and ready to go. If necessary, load up any templates you have created. When that's done, import your audio into the project. In post-production, you'll usually have a single audio file that needs work, rather than individual tracks.
The processing
In an ideal post-production situation, the sound will be well-recorded and mixed. There will not be any need to drastically change it or perform any brutal edits. However, there are some tools which can sharpen and polish the audio. First of these is the EQ, or Equaliser. It should be used sparingly, and if possible, should be a linear-phase model (in other words, one which does not colour the sound too much). To begin with some shelving cuts at the extreme high and low ends will help remove any additional hiss and rumble respectively. Then, try a gentle boost in the upper regions before the shelf. Whether in sound engineering or music engineering, this will help the sound sparkle on any system. Similarly, compression should be applied sparingly. The idea is to catch the extreme peaks of the sound, rather than to drastically squash it. A high threshold and a low ratio are ideal here, combined with a medium attack and release. After ensuring there is no clipping on the master out, set the locators and export the finished file. WAV or MP3 files are best - the former is best for quality but suffers from large file sizes, while the latter is small in size but low in quality. WAV is generally considered best for professional uses. Music production and sound production rely heavily on this kind of post-production, so it pays to spend a little time getting it right.