Specifications

Audio Plug-Ins Guide512
is easily identified: the samples themselves do
not represent the peak value of the waveform.
The waveform is only complete after the recon-
struction process. Until this process has been
completed, the waveform is inaccurately repre-
sented by the samples. This is the reason that in
most DAWs the waveform is represented on the
screen as a “dot to dot” connection between
sample points. They do not undergo the recon-
struction process inside the system, so all that
can be represented is the sample points and for
the sake of visual ease, they connect the dots be-
tween them with straight lines. They save the re-
construction process for the digital to analog
converters.
The consequence of the way in which DAWs
treat waveforms is that the meter inside the
DAW or other digital mixers inevitably shows
inaccurate information. It is virtually a mathe-
matical certainty that the waveform will exceed
the amplitude of the samples in any sampling
system. The samples themselves only represent
a waveform. It is important to understand that
the amplitude of the waveform will invariably
exceed the sample values.
Manifestation
Today’s recording environment demands that
sessions are mixed and mastered as “hot” as is
possible, pushing the levels up to the highest tol-
erable amount, supposedly just short of clip-
ping. Sophisticated digital tools allow music to
be highly compressed, then recompressed, com-
pressed even more so with multi-band compres-
sors, limited, normalized, and maximized to get
the audio to play as loud as possible out of a con-
sumer’s system. Hence, it is very common for
popular music CDs to be full of digital samples
that are at, or nearly at full scale.
The problem is realized in that while going
through these digital gyrations and utilizing
digital tools to amplify the signal as much as
possible, both during mixing and during mas-
tering, the “peak value” of the sample points is
closely watched to ensure that it does not get to
full scale. Since the peak meters in said DAW
and digital mixing systems are inaccurate, and
do not actually indicate the peak values of the
resulting waveform, the result is that while the
samples themselves do not exceed full scale and
are carefully monitored to ensure this, the re-
sulting waveforms represented by the samples
may exceed full scale throughout any standard
CD!
While the digital mixing system is not clipping
the music or distorting the music, the digital to
analog converters that have the task of recreat-
ing the audio through digital reconstruction fil-
ters are clipping repeatedly throughout most
CDs on the market. The result is that most CDs
and DVDs end up distorting with regularity
when they are asked to reconstruct and play
back audio that appears to be completely “legal”
because not a single sample actually clipped.
Intersample peaks
D/A converter range