Apple Soundtrack Pro 2 - Manual (Page 497)

Appendix C Working with Professional Video and Audio Equipment 497
Frequency Response and Dynamic Range
Speaker quality varies greatly depending on their purpose as well as their price. For
example, speakers in a portable stereo or television are designed to play audio that has
already been mastered by a mixing engineer. Mastered audio such as audio CD, radio,
television, and movie sound has a compressed dynamic range (meaning levels are fairly
consistent and loud).
Speakers and amplifiers that are designed for mastered audio often intentionally
emphasize certain frequencies, as is done with the bass enhancement feature found on
many systems. This may make an audio CD sound better, but it is not recommended for
mixing production sound because you get a false impression of the audio signal. For
example, if your speakers overemphasize frequencies around 2 kHz, you may
compensate during mixing by reducing the intensity of audio around 2 kHz. If you then
play your mix on a different set of speakers with a flat frequency response, the
frequencies around 2 kHz will sound too muffled.
Self-Powered Versus Passive Speakers
Speakers powered by an external amplifier are called passive speakers. When you use
separate amplifiers and passive speakers, a number of factors affect the overall
frequency response and quality of your audio. Instead of using a separate amplifier and
speakers, a simpler option is to use self-powered speakers (speakers with built-in
amplifiers). These have become increasingly popular, especially for studio monitoring
and video editing.
Self-powered speakers deliver more consistent performance because both components
are designed to work together and are housed in a single enclosure. For video editing
systems, self-powered speakers are a good, easy-to-use solution. Self-powered speakers
accept line level inputs, so it’s fairly easy to connect them to your audio interface.
Flat Not flat
20 Hz 200Hz
– dB
+ dB
– dB
+ dB
1 kHz 5 kHz 20 kHz 20 Hz 200 Hz 1 kHz 5 kHz 20 kHz