Apple Final Cut Express HD - Manual (Page 569)

Chapter 41 Setting Up Audio Equipment 569
VIII
Choosing Speakers and an Amplifier for Monitoring
Professional audio engineers mix by listening, so they have to be able to trust the sound
coming from their speakers. When you mix your audio, you need audio monitors that can
handle the full range of audio intensities and frequencies. Ideally, your monitors will have
a flat frequency response from 20 Hz to 20,000 Hz (or 20 kHz). This means that they neither
attenuate nor amplify any frequencies. Flat frequency response is important for critical
listening because the speakers themselves are not coloring the sound.
In addition to the speaker quality itself, additional factors affect your audio
monitoring environment:
 Size and materials of the room
 Placement of the speakers within the room, such as distance from walls and angle
of speakers
 Listener position between speakers
Frequency Response and Dynamic Range
The quality of speakers varies greatly depending on their purpose as well as their price.
For example, speakers in a boombox 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.
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