Open Cool Edit Pro. Double-click the desktop icon or click "Start," "Programs" and "Cool Edit Pro."
Click "Edit View" in the toolbar. Click "Choose File" and select the mix of the song you want to master. In mastering, you don't need the individual audio files -- just a mixed version of the complete audio.
Click "Effects" and select "Mastering Rack" from the drop-down menu. Click the triangle icon next to the first vacant channel on the rack and select "Filters," "Parametric Equalizer." This tool lets you boost, cut and balance the various frequencies in the track, so you can cut out unwanted hum or noise and boost frequencies that are a little low.
Click the triangle icon again and select "Amplitude," "Multiband Compressor." A multiband compressor lets you limit the dynamic range of various frequencies, to create a more compact and level-sounding master mix. Click the triangle once more, select "Amplitude" again and this time select "Stereo Expander." This tool lets you manipulate the width and spacial arrangement of the stereo image by using a panning effect. Now that you've set up your three-row mastering rack, you can begin applying the effects.
Click "Play" and listen to the track. Click on the "Parametric Equalizer" interface and select one of the pre-set configurations. Click the power button on the "Mastering Rack" to turn the effects off. This bypasses the entire signal chain and lets you hear the track with and without the mastering effects.
Tweak the dials in the equalizer to customize the preset. There is no right or wrong way to master a track, as each audio calls for a different treatment. Listen out for adjustments that enhance the brightness of the vocals. If you make a small adjustment that has a pleasing effect, continue with the same adjustment to explore the limits.
Tweak the dials in the "Stereo Expander" to make small adjustments to the frequency arrangement in the audio. Click "Ctrl+Z," or "Command + Z" if using a Mac, to undo any unwanted amendments.
Click on a specific area of the waveform graphic that appears in the mastering rack. Drag it around the grid to highlight the various frequencies. If at any point the sounds become muddy or fuzzy, click on the multiband compressor. This will open on the exact frequency highlighted on the waveform graphic. Reduce the "Gain" dial to cut the rogue frequency in the mix, adding clarity to the overall audio.