How to buy ... a SACD or DVD-Audio player

Just when you had your two-channel stereo set up perfectly, along come two new music formats promising a brave new world of high-resolution, surround-sound audio.

The Big Picture
Life in the audio world used to be simple. There were two channels, two speakers and a little plastic disc storing high-quality, digitised audio that was so compact they called it a … compact disc. But things have changed since then, DVD-Video has taken over the world and people from all walks of life have merrily littered their lounges with multiple speakers and gigantic subwoofers to literally surround themselves with sound. Naturally the audio industry saw what was going on, thought “we’d like some of that pie too” and set about creating the next generation of audio disc, one they hoped would replace the CD and make everyone a stack of money in the process.
Sadly for the hi-fi connoisseur, and in a predictable display of bullish corporate stubbornness, two rival groups of electronics manufacturers decided building the next generation of audio disc would be a cool thing to do and set about creating two wholly incompatible technologies (bizarrely, this is going on at a time when mainstream consumers are leading the recording industry away from high quality in favour of digitised MP3 audio). Sony and Philips, creators of the original compact disc, gave the world Super Audio CD (SACD) while Panasonic and other industry members developed DVD-Audio.

Looks can deceive
At first glance both formats look to offer identical products. Both SACD and DVD-A can (but don’t necessarily have to) employ multiple, discrete audio channels in a 5.1 configuration like that of Dolby Digital in the DVD-Video world. Both also offer much higher-resolution audio than a standard CD to (theoretically) provide vastly improved sound. The differences between SACD and DVD-A lie not in the resulting output but in the physical manufacture of the discs, and the way in which the audio is recorded and processed.

Super Audio CD
If we play the semantics game for a second, we could say Super Audio CD is actually a slightly misleading name, because at its technological heart SACD is less like a CD than a DVD-Audio disc. Nevertheless, the marketing types at Sony and Philips no doubt wanted to keep an air of familiarity about their new format and did so by incorporating the letters C and D in the name. And who could blame them?
Four types of SACD are currently available, what sort you should buy only becomes an issue if you don’t have an SACD player. “Huh?” I hear you say. SACD Hybrid discs actually contain two layers of audio — the first layer is semitransparent and contains up to 4.7GB of high-resolution, multichannel SACD audio, while the second layer contains around 780MB of standard, CD-compatible stereo audio. This second layer of a Hybrid disc is essentially just a plain old compact disc and will happily play in any of the millions of CD players currently in use around the world. The first layer, however, will only play in a dedicated SACD player. The beauty of this is that you could potentially start buying all your music in Hybrid SACD format even if you don’t have an SACD player and make the switch later without doubling up your music collection. The only problem with this tactic is that SACDs aren’t all that common, so you may not have a choice at your local music store as to what you can purchase. Likewise, not all SACDs contain the CD layer. These non-Hybrid discs won’t play in anything other than an SACD player, so pay close attention to the label.
So that accounts for two types of SACD, what about the rest? Besides Hybrid and non-Hybrid you can buy multichannel SACDs and two-channel stereo SACDs in either a Hybrid or non-Hybrid format.

DVD-Audio
A DVD-A disc, on the other hand, won’t play in an ordinary CD player, but it will play in just about any DVD-Video player on the market. However, if you aren’t using a proper DVD-Audio-compatible player, you’ll not be able to take advantage of the high-resolution multichannel audio on the disc. Instead you’ll likely be listening to a highly compressed Dolby Digital mix that, while still making use of the 5.1 channels, won’t offer any of the benefits of increased audio resolution. Like SACD this dual compatibility means you can start buying and using DVD-A before you’ve even made the investment in hardware.

Multichannel
Both DVD-A and SACD sell themselves on being able to use six channels of audio, but remember, just because you can record an album using all six channels, that doesn’t necessarily mean you should. Ideally the recording engineer and artists will decide what suits their music best; live albums benefit hugely from a full six-channel mix, as the rear speakers add immensely to the feeling of being in the crowd. But some studio albums may be more suited to a straight stereo mix — there’s nothing worse than listening to an album and being distracted by the sound of extraneous instruments suddenly popping out of your rear speakers. A good engineer, however, can use those rear speakers to create ambience and depth in the music. Of course, in some respects, despite the technology surrounding SACD and DVD-A, one thing hasn’t changed since the dawn of recorded music: a good recording will probably sound good no matter what the medium, while a bad recording will sound bad on even the best hi-fi system.

High resolution
Channels aside, the other major selling point for SACD and DVD-A is the massively increased audio resolution each is capable of storing. Both feature a frequency response of up to 100kHz (compared with 22kHz for CD) and vastly increased sampling rates of up to 192kHz for DVD-A and a staggering 2.8MHz (roughly 2800kHz) for SACD (standard CDs sample at 44kHz). One of the problems engineers struck with the original CD format was how to compress the audio to fit the disc capacity. The extra space and higher sampling rates offered by SACD means engineers can now produce a recording where the wave form output more closely matches the original waveform that was input during the recording phase. That’s the potential. In practice we’re again at the mercy of those making the recordings when it comes to the quality we get out of an SACD or DVD-A disc.

The hardware
You’ll need a hardware upgrade to play SACD or DVD-A discs. Even though both formats offer a degree of backwards compatibility — SACD with CD players and DVD-A with DVD-Video players — you won’t extract full enjoyment out of either format if you aren’t using their high-resolution players. While it’s possible to buy either SACD-only or DVD-A-only players, the existence of universal players produced by electronics manufacturers without a vested interest in one format over the other takes away the stress of having to choose sides. Operationally you won’t find any differences over, say, a regular CD or DVD, but you will find DVD-As often provide little extras such as video clips, static images and song lyrics.
Perhaps the biggest problem on the hardware side of things is that because of the way copy protection is implemented you’ll need a receiver with either a secure digital audio input such as iLink (IEEE1394) or 5.1 analogue inputs to get your multichannel, high-resolution audio signal from your player to your processor. Keep an eye out for either of these options if you think SACD or DVD-A is something you might be interested in at some stage.

Which is better?
If ever there was a time to sit on the fence, this is it. We can’t decisively say that one technology is better than the other. Besides, with universal disc players you don’t need to choose one or the other; have both instead!

Other considerations
Hardware limitations: Sony and co have spent billions inventing a system of recording and mastering high-res audio at ridiculously high sampling rates with more detail than you care to think about. Yet many receivers’ analogue inputs use analogue-to-digital PCM converters and digital-to-analogue converters that operate at the same 44kHz rate as plain old CD audio. In effect you’re wasting all the high-res bandwidth at the very last step in the audio processing chain. If you’re shopping for a receiver, check to see what kind of audio DACs (digital-to-analogue converters) it comes equipped with. The higher the better.

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