dbx Type IV
TM
White Paper
504X
504X Digital Output Card
®
15
the forgiving nature of analog tape allows users of analog recording equip-
ment the luxury of only needing to monitor the average level using VU
meters, often having no peak indicators whatsoever. If only digital were
more forgiving like analog, we could really exploit its wide dynamic range
and more completely capture the essence of the musical performance.
Enter the dbx Type IV™ Conversion System. Like its related predeces-
sor technologies—Type I™, Type II™, and Type III™—dbx Type IV™ suc-
ceeds in preserving the wide dynamic range of the original analog signal
within a limited dynamic range medium. Whereas Type I™ and Type II™
expand the dynamic range of analog tape and other limited dynamic range
media, and the simultaneous encode/decode process of Type III™ simi-
larly expands the limited dynamic range through minimum-delay devices,
Type IV™ breaks new ground by greatly enhancing the useable dynamic
range of the analog-to-digital conversion process.
The dbx Type IV™ Conversion System combines proprietary analog and
digital processing techniques to capture a much wider dynamic range than
the A/D converter could by itself, preserving the maximum amount of
information from the analog signal. This information is then encoded with-
in the available bits of whichever A/D converter is used. This means that
Type IV™ improves the performance of any A/D converter, from low-cost
16-bit to high-performance 24-bit! And no decoding is necessary beyond
the conversion process!
As we have previously mentioned, digital systems have a wide linear
region compared to analog tape and the dynamic range of A/D converters
has improved significantly in recent years. The dbx Type IV™ Conversion
System takes advantage of this and utilizes the top 4 dB of the A/D con-
verter’s linear dynamic range to create a logarithmic “overload region.”
This allows high-level transient signals passing far above the point where
the overload region begins to be adequately represented in just 4 dB of the
converter’s dynamic range, whereas a typical A/D converter would clip.
With Type IV™, you can never clip the A/D converter!
Summary of Contents for dbx 504X
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