The Outlaws’ Guide to the Marantz AV7005
Dolby Digital Plus
Dolby Labs developed a successor to Dolby Digital for use with HD-DVD, Blu-ray, and
satellite TV. This audio format is called Dolby Digital Plus (DD+). Dolby Digital Plus
offers 7.1 or more discrete channels (rather than 5.1). It also employs more powerful
lossy compression, enabling both lower bitrates and higher quality at higher bitrates.
This format can only be delivered to the receiver in its native form via HDMI or
transcoded to Dolby Digital 640 kbps for output via coaxial or optical digital audio.
Dolby TrueHD
Dolby TrueHD was developed for use with the new HD disc formats, HD-DVD and
Blu-ray. The technology is an extension of Meridian Lossless Packing (MLP), the
lossless audio compression format employed on DVD-Audio. Since the compression
used does not discard any data, a TrueHD track preserves the original integrity of the
uncompressed master.
DTS
DTS is an alternative to Dolby Digital that shares the same basic concept: six channels
of audio, compacted using a lossy compression algorithm to save space. DTS uses an
algorithm that is not as efficient as Dolby Digital and therefore not as heavily
compressed, which many people believe allows it to sound better.
DTS-HD High Resolution
DTS responded to Dolby Digital Plus with DTS-HD High Resolution. DTS-HD High
Resolution is an extension to DTS 96/24 that allows higher bitrates, but it still employs
lossy compression. Like DD+, DTS-HD HR supports 7.1 channels, may be included on
both Blu-ray and HD-DVD, and can only be transmitted via HDMI v1.3 or higher.
DTS-HD Master Audio
Despite the similarities in name, DTS-HD Master Audio is a completely separate audio
format from DTS-HD High Resolution. Like Dolby TrueHD, DTS-HD MA employs
lossless compression to provide a format that offers the sound quality of an
uncompressed PCM track while offering a way to use less disc space. DTS-HD Master
Audio also supports 7.1 channels.
Multich PCM
HDMI allows sources to output multichannel PCM because the connection can support
the greater volume of data required to transmit up to eight channels of uncompressed
digital audio. A multichannel PCM signal may be as delivered directly on a Blu-ray Disc,
or as derived from any compressed audio bitstream the player can decode (including
the formats listed above).
DSD
DSD (Direct Stream Digital) is a data format that differs significantly from PCM. It was
originally developed for professional archiving purposes, and was then adapted for use
with the high-resolution audio disc format SACD (Super Audio CD). There are a small
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Marantz AV7005
Audio Formats and Listening Modes
