Hybrid SACD/DVD (Part 1 of 3)
By Stefan Schreiber
The present situation
The current situation is well-known and unsatisfactory: the simultaneous market-introduction
of two competing standards for high-resolution audio and surround-sound (DVD-Audio
and SACD) is leading to big problems in the audio industry - and additionally,
to frustration for audiophiles and "consumers" who are, in some cases, unable
to reproduce on their audio-players a disc available for the competing standard.
As even DVD-Video is apt to distribute audio-recordings (and, of course, music-video),
it could be said that there do exist three potential "CD successor" formats
at the same time.
While the SACD standard allows a hybrid disc-form containing a CD-layer compatible
with CD-players, DVD-Audio discs are often mastered as DVD-AudioV, containing
audio recordings for normal DVD-players (Video), often in stereo (for example,
PCM-96kHz), or in compressed surround-formats (Dolby Digital, DTS). Of course,
DVD-AudioV discs can include music-video and further "extras".
As a "general" solution for the ongoing format-war between SACD and DVD-formats,
it is often demanded that all new and advanced audio reproducers were "hybrid
players", supporting both formats. These hybrid players should support the "DSD" (kind
of high-resolution bitstream) modulation of SACD, and PCM in all quality levels
of DVD-Audio (up to 192kHz, 24Bit). Although this sounds very convincing, it
won't happen, in my opinion.
It is quite possible to equip hybrid players with chips supporting both formats,
and also to design combined DACs supporting both DSD- and PCM-modulations.
However, good reproducers will need different analogue paths after the conversions.
The price of audio reproducers is mainly a consequence of good analogue components
and DACs, not of ICs supporting two or three formats "digitally".
Some of the announcements made by Chinese manufacturers about the possibility
to offer DVD-players with DVD-Audio- and SACD-support, for maybe $100, have
to be considered from a critical point of view. The problem is not to support
a format "digitally" and to reproduce it "somehow"; you have to do it well,
especially in the case of audio. Otherwise, you wouldn't have to replace the "Compact
Disc" at all, which already can sound quite well, but certainly not "perfect
It is difficult to design a DVD-player with "good" audio-quality. It is needed
experience and know-how for this task. Up to now, hybrid SACD/DVD players are
usually better for ONE of the two formats, for example, because they convert
DSD to PCM (up to 192kH) and vice-versa. This conversion isn't completely "without
loss", and will result in "PCM with less dynamic bandwidth", or in "DSD with
less temporal resolution".
It is revealing that hardly any hybrid SACD/DVD-Audio player can be considered
to be a CD-player of "reference-class", which, considering sometimes high prices,
is quite amazing, because you can very well "upsample" PCM in 44.1kHz/16Bit
both to PCM in 96kHz (or 192kHz) AND to DSD, all in the digital domain. Expensive
CD-players are quite often doing exactly this...
The current (and maybe future) low market-share of such hybrid players has
very understandable reasons. The DVD-player market is extremely price-competitive.
If a DVD-player is also a hybrid DVD-A/SACD player, it would be too costly
and in a too high price-category for most customers. Audiophiles would consider
buying such hybrid players, but they will be normally too expensive to be competitive
in the mass-market. A DVD-player supporting both formats won't be a best-selling
model, for price-reasons. Today, and probably also in future, obviously not
every DVD-player is even supporting only ONE of the two high-resolution formats.