Anthem AVM 20 v2 - Manual (Page 34)

5. FRONT PANEL OPERATION
continued …
5.8.4 DOLBY DIGITAL EX
Dolby Digital EX can be used to decode DVDs encoded in Dolby Digital Surround EX. Dolby Digital EX uses
Dolby Pro Logic II to extract the rear channel information from the two Surround channels. Dolby Digital EX
can also be applied to Dolby Digital 5.1 channel material that is not encoded in Dolby Digital Surround EX,
however, the Rear channel information may or may not be pleasing depending on the soundtrack.
A list of movies encoded in Dolby Digital Surround EX can be found on the Dolby web site at www.dolby.com
and THX web site at www.thx.com. Since most titles currently do not have a flag to engage Dolby Digital EX
decoding automatically, be sure to set Dolby Digital EX to ‘On’ when playing unflagged Surround EX titles –
while the DVD is playing, press MODE and use the Master Control Knob to turn Dolby Digital EX ‘On’. To
automatically decode DVDs that contain the Surround EX flag, set Dolby Digital EX to ‘Auto’.
Note: To use Dolby Digital EX without THX processing, THX must be ‘Off’ (see section 5.8.6).
5.8.5 DTS-ES
There are two ways that Rear channel information is encoded in DTS-ES – Matrix and Discrete:
• Matrix – DTS-ES Matrix movies contain a matrixed Rear channel. The AVM 20 automatically
engages Neo:6 to decode DTS-ES Matrix. As well, Neo:6 can be turned on manually and applied to
DTS 5.1-channel material – while the DVD is playing, press MODE and use the Master Control Knob
to turn Neo:6 ‘On’. A mono Rear channel will be derived from the Left and Right Surround channels.
This Rear channel may or may not be pleasing depending the soundtrack and your preferences.
• Discrete – DTS-ES Discrete movies contain an independent Rear channel. When one of these
movies is playing, the AVM 20 automatically engages DTS-ES Discrete decoding.
5.8.6 THX ULTRA2 / THX SURROUND EX
Each THX mode includes a specific combination of the following:
• Re-Equalization – De-emphasizes high frequencies in the front channels, and in THX Surround EX,
the rear channels as well. Soundtracks commonly have pre-emphasized treble because they are
mixed for movie theaters where high frequencies are usually absorbed. They can then sound overly
bright when played back in the home. Re-Equalization restores the correct tonal balance for
watching a movie soundtrack in a home theater environment. Some TV shows that are broadcast
in Dolby Surround also benefit from Re-Equalization, whereas some movies on DVD may already
have Re-EQ applied and do not require it from the processor. To defeat Re-EQ, press the THX button
a second time after selecting a THX mode to display “RE-EQ Filters: On (Off)”, then adjust.
• Timbre Matching – The human ear changes our perception of a sound depending on the direction
from which the sound is coming. In a movie theatre, there is an array of surround speakers so that
the surround information is all around you. In a home theatre, you use only two speakers located to
the side of your head. Timbre Matching, which includes Re-EQ, filters the information going to the
surround speakers so that they more closely match the tonal characteristics of the sound coming
from the front speakers. This ensures seamless panning between the front and surround speakers.
• Adaptive Decorrelation – In a movie theatre, a large number of surround speakers help create an
enveloping surround sound experience, but in a home theatre there are usually only two speakers.
Unless you are using properly positioned dipoles, surround speakers can sound like headphones
that lack spaciousness and envelopment – they will also collapse into the closest speaker as you
move away from the middle seating position. Adaptive Decorrelation senses the presence of
identical surround channels (mono) and slightly changes one surround channel's time and phase
relationship with respect to the other. This expands the listening position and creates – with only
two speakers – the same spacious surround experience found in a movie theatre. Adaptive
Decorrelation does not operate when the surround channels are different, as is often the case in
discrete multichannel source material.
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