Mastering calls for a precise tweaking of frequencies and dynamics. The multi-band compressor tool enables you to enhance and cut various frequencies. The compressor splits the audio into four bands: sub-bass, bass, middle and treble. Use the slider dial to increase or cut each band according to what the audio requires. For example, if the audio is bass-heavy it can sound "muddy" at high volumes. Use the multi-band compressor to reduce the prominence of the sub-bass and bass frequencies to give the other frequency ranges "room to breathe."
When editing audio to remove unwanted noise, zooming in helps you execute more accurate corrections. Click "View" and select "Zoom" to enlarge the audio sound wave graphic. The sound wave graphic represents the audio as a series of peaks, dips and flat lines much like a heart-rate monitor. The tall peaks are strong signals, the smaller peaks are weaker signals and the flat lines represent silence. Once you have zoomed in on a peak, you can use the "Scissors" tool to remove unwanted sounds, such as those created when the singer draws a breath between lines.
To get truly professional results, load a commercially released recording onto your computer and import the audio file to the Cool Edit Pro interface. Open up the "Spectral Analysis" tool. Cool Edit Pro displays the audio of the commercially mastered track alongside the track you are mastering. This way you can view both audio tracks side-by-side to see and make visual adjustments based on what you see. This allows you to more precisely emulate the techniques that the professionals use when mastering.
As well as rendering the audio so that it finishes up as clean and bright as possible, "tidying" is an important part of the mastering process. During recording, certain undesirable sounds, such as a hum or hiss from microphones and instruments, make their way onto the track. Rather than going through each track and manually removing each hiss or pop, Cool Edit Pro has an automated "Hiss and Pop Reduction" tool that does it for you. The likely frequencies of undesirable noises are pre-configured in the software, so Cool Edit Pro automatically reduces the prominence of those frequencies. This can save you a lot of effort.