Griffin Technology Final Vinyl 2.5 - Manual (Page 10)

More About EQ Settings
The sliders in the EQ window let you set the bass,
treble, and mid-range to control the way your music
sounds. The Gain slider at the far right of the EQ
window will increase or decrease the overall volume
within a range of +/- 20dB. Once you have the EQ
settings the way you want them, press the “Apply”
button, and Final Vinyl applies the settings to the
recorded audio.
An equalizer increases or decreases the volume
within a selected frequency range; for example, you
can move the EQ sliders to boost the bass range
without affecting the treble. Keep in mind that
boosting a band of frequencies boosts your overall
signal as well. For example, if all of the frequency
sliders are raised 50% above normal, the audio will
be 10dB louder; if all the sliders are lowered 50%
below normal, the sound will be 10dB softer. The
trick is to balance all your various volume controls
(including your Mac’s sound panel, Final Vinyl’s Gain
setting in Preferences, Final Vinyl’s EQ settings, and
possibly others, depending on your setup) so that the
resulting audio never exceeds 100%.
Continuing the example of raising all the sliders 50%, and assuming
the incoming audio is set so that the loudest sound in the recording
reaches 100% loudness, that would mean the final audio volume would
be at 150%! If the total volume is more than 100%, the “peaks” of the
audio signal will be “clipped off,” which results in a very nasty-
sounding distortion of the signal. Your ability to perceive distortion will
depend on the environment where you listen (a very noisy environment
will make it hard to hear distortion) and on the style of music itself.
Very light distortion is easy to hear in soft classical music, but nearly
impossible to hear in thunderous heavy metal, which already contains
large amounts of distortion as part of the music.