Apple MA261Z/A User Manual - Page 586

When used sparingly, compression can help you bring up the overall level of your mix to compete with noise in the listening environment. However, if you compress a signal too far, it sounds very unnatural. For example, reducing the sound of an airplane jet engine to the sound of a quiet forest at night and then raising the volume to maximum would cause the noise in the forest to be amplified immensely. Different media and genres use different levels of compression. Radio and television commercials use compression to achieve a consistent wall of sound. If the radio or television becomes too quiet, the audience may change the channel-a risk advertisers and broadcasters don't want to take. Films in theaters have a slightly wider dynamic range because the ambient noise level of the theater is lower, so quiet sounds can remain quiet. Stereo Audio We hear sounds in stereo, and our brains use the subtle differences in sounds entering our left and right ears to locate sounds in our environment. To recreate this sonic experience, stereo recordings require two microphones, two tracks of recording, and two speakers for playback. The microphones and speakers must be properly positioned to the left and right to accurately recreate a stereo image. If any one of the above elements is missing, the stereo image will most likely be compromised. For example, if your playback system has only one speaker, you will not hear the intended stereo image, even if the rest of your recording system meets the above requirements. Important: All stereo recordings require two channels, but two-channel recordings are not necessarily stereo. For example, if you only use one microphone but record that signal on two tracks, you are not making a stereo recording. A proper stereo recording must meet all of the above requirements. 586 Part VIII Audio Mixing