Compelling soundtracks are essential for powerful video stories. It was long ago proven that to hold the attention of an audience, the quality of audio is more important than the quality of video. Creating powerful audio tracks is an art form and there are a myriad of useful effects available to video editors. Two of the most important are EQ (for equalization) and compression.
Essentially, EQ is the process of adjusting the volume of different frequency bands within an audio signal. The processing is done through an equalizer — either a software plug-in or outboard hardware device. The bass and treble controls on a high-fidelity receiver are a simple form of an equalizer.