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unwrAP HD
UnWrap HD
Professional Stereo to 5.1 Up-conversion
In a perfect world, all audio recorded over the last fifty
years would be available on multi-track tape formulated to
last for centuries. Unfortunately, the world is not perfect.
Where source tapes are in a useable condition, the best
way to take full advantage of the original material is
typically by performing a full remix., ideally producing one
type of master for every target format. However, reasons
can exist for preferring to up-convert instead:
• a classic mix is too sacred to touch
• there is not enough time or budget to do a new mix
• a multitrack source tape in a bad condition
• sound effects have to be spread to 5.1 for cinema
presentation or HD broadcast
• an up-converted original is requested as a benchmark
when remixing
Introduction
UnWrap HD puts the process of converting from stereo
to 5.1 in the hands of an audio professional – where
it belongs. It is the world’s primary high-resolution
up-conversion processor, and with its wealth of controls,
UnWrap HD is the de facto standard in film, post and
music production. Thanks to rigorous phase and resolution
preservation in the algorithm, up-converted material may
even be subsequently down-mixed to stereo again with no
sonic penalties. Processing is 48 bit, and sample rates up
to 96kHz may be used.
Unwrap HD is not a one-size-fits-all solution, but provides
a host of parameters to aid the design of a result faithful
to the original with regards to width, timbre, spaciousness,
foreground/background discrimination, and other important
factors. Still, there may be situations where up-conversion
won’t provide a satisfactory result, and where the
recommendation would be perform a new mix or forget it.
UnWrap HD comes with up-conversion presets for the type
stereo and LtRt program material typically dealt with in
broadcast, film production and music mastering. Presets
are located in Factory Bank F11, decade 3-6.
UnWrap™ and UnWrap™ HD
The original algorithm was called UnWrap, while the latest
version with more dialog and envelopment extraction
functions is named UnWrap HD. Presets generated with
the original UnWrap application can be read using UnWrap
HD, and still sound precisely like when they were created.
Presets generated with UnWrap HD, however, cannot be
loaded in UnWrap.
UnWrap HD in use
UnWrap HD measures phase, delay and spectral
differences between a pair of stereo channels to create
a 5.1 result. For different program material there will be
different parameter settings that best represent the original
mix. For different speaker setups, the same is true. For
instance in film production, Surround arrays produce a
more diffused sound than when using a point source ITU
R-775 speaker setup, so the level and spectral balance
of the presets should not be regarded as set in stone.
Instead, Factory presets should be used as starting
points. Please familiarize yourself with the controls and
parameter-ranges on known material and a known 5.1
monitor system before attempting to unwrap new stuff.
Setting up
The best practice is to monitor the outputs of UnWrap
HD through the Toolbox 5.1 (e.g. by loading preset “5.1
Monitor Matrix”).
This way you can check all speakers one by one with pink
noise first, and also collapse the 5.1 signal to stereo or
mono to make sure the result is still hearable. Try loading
some of the UnWrap HD presets. You can A/B the process
by pressing Bypass on the UnWrap HD Engine, or collapse
the signal to stereo again by selecting Stereo format on the
Toolbox Engine, if it is inserted downstream as suggested.
The UnWrap HD algorithm occupies:
@ Normal Sample Rate : 1/4 DSP Resource
@ Double Sample Rate : 2/4 DSP Resource
Algorithm Inputs/Outputs are distributed as follows:
E1 - E4
L
R
L
R
C
LFE
SL
SR
INPUT
OUTPUT
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