Tips for choosing speakers and an amplifier, Frequency response and dynamic range – Apple Final Cut Pro 7 User Manual

Page 861

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Tips for Choosing Speakers and an Amplifier

Professional audio engineers 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 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.

Flat

Not flat

20 Hz

200 Hz

– dB

+ dB

– dB

+ dB

1 kHz

5 kHz 20 kHz

20 Hz

200 Hz

1 kHz

5 kHz 20 kHz

861

Chapter 53

Assigning Output Channels and External Audio Monitors

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