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.