Are you ready for DVD-AUDIO?
Here's a quick overview of what DVD-AUDIO high resolution DIGITAL sound is all about:
So, you're ready for DVD-A, huh?
By Tony Martin
Introduction
By now you've likely heard or read a little something about DVD-Audio (DVD-A), the "other" DVD format out there that is confusing everybody. I mean, all DVDs produce audio to go along with the video, right? So any DVD player can be used for DVD-Audio, right? Well, the answer is both yes and no, depending on the situation. In this article, I'm going to address the details of setting up your home theater system for DVD-Audio. I'm going to assume that if you're reading this, you have (or intend to acquire) at least a basic home theater system consisting a Dolby Digital/DTS receiver, a DVD player, a TV, and 6-speakers (including subwoofer), with everything connected up and working.
Before diving head first into DVD-Audio, it is important to understand what it is. First, you should understand that a DVD-Audio title, like DVD-Video title, is simply an application of DVD-ROM. Both of them come on DVDs, with the primary difference being that one is for film while the other is for music. DVD-Audio is intended by its originators to be the next step in high-quality, high-performance audio. Its cousin, DVD-Video (DVD-V), is a goodly step beyond its predecessors (VHS and Laser Disc) in the sense that it offers high-quality video, multi-channel "CD-quality" soundtracks, and supplemental features on a platter the size of a CD. DVD-Video is intended to raise the bar on video-based entertainment, and offers multi-channel sound as well to enhance film realism. DVD-Audio, also offered up on a platter the same size as a CD, provides enhancements mainly in the area of audio, and includes features such as greater bit depth (24-bits instead of the 16-bits on CD), greater frequency extension (48 or 96 kHz as opposed to 22 kHz of CD), and greater dynamic range (144 dB instead of the 92 dB offered by CD). The high-resolution multi-channel and stereo tracks found on a DVD-Audio title are sonically superior to those found on a DVD-Video title, as well. DVD-Audio can also include video-based supplements that give information about the songs and artists performing on the disc. Both DVD-Video and DVD-Audio benefit greatly from the extra storage space afforded by DVD over CD (up to 18 GB as opposed to the paltry 680 MB or so offered by CD).
After absorbing that bit of info, it is only natural wonder what is the real difference between DVD-Video and DVD-Audio. One simplistic way of thinking about the differences is as follows. Most of the space on a DVD-video disc is devoted to storing compressed digitized video, due partly to the fact that video requires lots of space, but also because video quality is the primary concern. In comparison, the space devoted to compressed audio in support of the provided soundtracks is small compared to the space devoted to video on a DVD-Video disc, partly because the audio content on these discs doesn't take nearly as much space as video, and also because audio isn't the primary concern (but is still of considerable importance). Furthermore, on a DVD-Video disc, lossy compression techniques are usually applied to both video and audio, which means, in effect, that information has been thrown away in the compression phase of the encoding, which can never be regained upon decoding. In contrast, on a DVD-Audio disc, since the main purpose is to present high-quality and high-resolution audio, the storage space on the disc is used first and foremost for audio information. The compression technique used for the DVD-Audio tracks is lossless, meaning that the original encoded audio information can be recovered completely during the decoding phase. Titles that include a high-resolution 6-channel track along with a high-resolution stereo track can consume quite a bit of disc space depending on the length of the program material. While a DVD-Audio title can contain supplemental video and audio material, the quality of this material is a secondary consideration behind the high-resolution audio presentation.
The question of whether your DVD player can be used to play a DVD-Audio title depends on whether the producers of the disc have included compatible audio tracks. To date, the largest majority of the DVD-Audio titles available can be played in any DVD player. The producers of such titles have seen fit to provide audio tracks that can be enjoyed by the entire, quickly growing, DVD-player owning pubic, and they have wisely chosen to build in an upgrade path. More likely than not, if you get a DVD-Audio disc, it will contain, in addition to a high-performance multi-channel DVD-Audio track, one or more of the following: an enhanced 2-channel PCM track (stereo), a Dolby Digital 5.1 track, and/or a DTS 5.1 multi-channel track. The wise thinking of the title producers allows nearly any DVD-based system to play back the music encoded onto the platter, even though these titles cannot be played in a standard CD player. However, to get the best audio performance possible from a DVD-Audio title, you will need a DVD-Audio player as part of your home entertainment center.
Stepping up to DVD-A
It is probably no surprise that all DVD players were not created equal. The early model players had high-performing S-video outputs and digital bitstream audio output via coaxial connections. When the digital bitstreams were feed into a Dolby Digital capable receiver, a high-quality multi-channel soundtrack could be enjoyed along with the movie. Some players even included Dolby Digital decoders so that those who bought early model receivers without built in decoding capability could still enjoy multi-channel soundtracks. Later model players added bitstream support for DTS, too, and by this time the market had changed so radically that many early adopters had to upgrade to newer players and receivers to be able to get all of the latest features. Variations on the theme brought about multi-disc DVD players, and eventually the so-called "NUON-enhanced" players, and also players that had component video (and later progressive scan) outputs for the highest quality image on a monitor. Obviously, the DVD player market has been evolving at a very rapid pace.
One of the more recent enhancements to be added to late-model DVD players is the ability to playback DVD-Audio. Players that have this ability will display the DVD-Audio logo, which looks like:
Analog Outputs
Back in the early days of DVD, many receivers didn't contain on-board Dolby Digital decoders, but some were Dolby Digital ready, in that they contained analog inputs that could be feed by external decoders. Nowadays, because of this, a good number of DVD players contain on-board Dolby Digital decoders, that can feed 6-channels of analog output to Dolby Digital-ready receivers, and those that don't output the digital bitstream for use by receivers that feature the decoders. DVD-Audio players also have a set of analog outputs on their rear panel that are used for a similar purpose. As shown in Figure 1, these outputs will usually be labeled something like "External Out," "6-channel analog out," "Analog Out," or similar. There will be six connections for RCA-type plugs for each channel of a 6-channel system: front left/right, rear left/right, center, and subwoofer. These connections can also be used to output decoded signals to Dolby Digital ready receivers, but more important is the fact that these connections must be used to fully enjoy DVD-Audio. Since DVD-Audio uses MLP (Meridian Lossless Packaging) compression, and since the DVD-Audio signal is not output as a digital bitstream to a receiver or amp (as no receiver or processor has an on-board MLP decoder), the only current option for DVD-Audio playback is via these 6 analog outputs. Fortunately, DVD-Audio players contain high-quality digital-to-analog (D/A) converters and a MLP decoder to ensure superior sound quality.
A Basic DVD-A Setup
To have a basic setup for enjoying DVD-Audio, in addition to a DVD-Audio player, you also need an audio/video receiver that provides inputs for 6 channels of external audio. Fortunately, most Dolby Digital/DTS receivers sold today have these inputs, and can be referred to as DVD-Audio ready. The reason those inputs were included is so that once newer technology appears, your current Dolby Digital/DTS receiver would still be useful by allowing you to use an external decoder housed in another unit. Well, simply put, that newer technology is here in the form of DVD-Audio. With a DVD player capable of MLP decoding (a DVD-Audio player), you can listen to DVD-Audio titles by connecting the 6 analog outputs of your DVD player to the 6 external straight-thru inputs of your receiver. The connections, as shown in Figure 2, are fairly obvious. You connect the front-right-channel output (FR RIGHT) from your DVD player to the front-right-channel input of your receiver, following similarly for the five remaining channels, as shown. You should realize that most receivers don't perform any kind of processing on signals coming in over the external analog inputs. They simply pass the signals through the amplifier section and on to the speakers.
Cables
The cables that you need to make the connections seen in Figure 2 will terminate with RCA plugs. To have the best possible sound fidelity in your setup, you need to use high quality interconnect cables. I recommend using the 75-Ohm coaxial cables with gold-plated RCA connectors on either end that are typically used for video applications, as opposed to those low-quality, el cheapo cables that most manufacturers include inside the box. These can be found at your local electronics store (Best Buy, Circuit city, Radio Stack, etc.) or at
www.bettercables.com. One advantage of getting your cables at Bettercables.com is that you can get special cable lengths that minimize the amount of cabling behind your home-theater system. This can be important in keeping the "spouse approval factor" high.
Fire It Up
To listen to a DVD-Audio disc using the above basic setup, you simply need to insert a DVD-Audio disc, select the appropriate DVD-Audio track (as opposed to the linear PCM, Dolby Digital, or DTS track), and then hit your play button. Also, you must set your receiver to play the signal coming in over its external inputs. Keep in mind that it is possible for a DVD-Audio player to output a 6-channel Dolby Digital or DTS signal over its analog outputs, since most of these units have built-in Dolby Digital/DTS decoders. On double-sided DVD-Audio discs, the DVD-Audio tracks will be on one side, while the Dolby Digital/DTS track will be on the other. To be absolutely sure you are playing the correct side, look for the LED or indicator on the front panel of your DVD-Audio player that indicates that the player is indeed decoding in MLP mode. On my JVC XV-D723GD player, the letters MLP light up and DVD-Audio LED shines in blue. On single sided DVD-Audio disc, the player should default to outputting the DVD-Audio track on the external outputs, even if Dolby Digital or DTS tracks are available.
Flies in the Ointment
Unfortunately, the above basic setup is not always a perfect implementation in practice. It will work, of course, and you can definitely listen to DVD-Audio titles. However, depending on the source material that you have and your particular setup, you may find that listening to either the Dolby Digital or DTS tracks that may be included to be a more enjoyable experience. The reason for this is twofold. First, most home theater systems don't include 5 good quality, full-range speakers, but instead depend on smallish main and surround speakers, along with a subwoofer. Second, most receivers available today simply pass the signals coming in over the external inputs straight through to the amplifier. In a system that has 5 good-quality, truly full-range speakers - meaning that they accurately produce sound frequencies over the entire audio spectrum from above 20 kHz to at, or below, 20 Hz - the above setup would work very well. However, the 5 speakers needed would likely be very large, for to produce 20 Hz accurately, and without noticeable distortion, would require fairly large drivers, adequate speaker housing, and good amplification in all speakers. Thus, while this is certainly not out of the realm of possibility, it is beyond what most people are willing to pay for, and it is also something that most people would be unwilling to allow in a home environment, where comfort and esthetics are typically very important.
Bass management
Long story short, the powers that be in the home theater world decided to address this issue head-on. Wisely, they anticipated that few would be willing to pay for and allow 5 really large speakers in a home. It is much easier to sell the idea of two smallish floor-standing speakers in front (which are typically allowed in most homes due to the 2-channel era), a fairly small center speaker, and two bookshelf-sized rears. In fact, in many cases, all speakers in a home theater will be small bookshelf-sized units. In these situations, it makes sense to use a subwoofer, and to route all of the really low-frequency signal energy that would typically go to the other speakers, along with the limited frequency-content LFE channel (the .1 in 5.1), to the sub. Thus, the concept of bass management was born.
Bass management proved to be a winning idea for the blossoming home theater market and has been incorporated into every A/V receiver with Dolby Digital capability. Thus, depending on your speakers, you can tell your receiver to route the low-frequency energy to a speaker that can faithfully reproduce it. This means that your smaller speakers won't be overwhelmed with signal energy they can't faithfully convert to pleasing sound, while, thanks to the subwoofer, all frequencies in the material you are listening to will be faithfully reproduced.
The first part of the "fly" in all of this is that the creators of DVD-Audio made no previsions for bass management. Hence, they assumed that the playback system for DVD-Audio would include 5 tonally matched, full-range speakers. The second part of the "fly" is that most vendors to date have produced A/V receivers that only provide bass management for Dolby Digital/DTS signals coming in over the digital inputs. Since the home theater market has evolved along the direction of systems that employ less than full-range speakers, the incorporation of DVD-Audio into most typical home theater systems is a bit more complicated than it might have been. This is why, in the setup of Figure 2, the DD/DTS tracks on a DVD-Audio disc might sound better than the corresponding DVD-Audio track - the bass energy in the DD/DTS track is being properly routed to the subwoofer (depending on the other speakers in your setup) while that in the DVD-A track is being sent to speakers that can't adequately reproduce those frequencies - resulting in either audible distortion, the absence of certain sound content, or possibly damage to the speakers. A growing trend in the industry is the inclusion of bass management on the 6-channel external analog input, but this is only showing up on high-end and add-on equipment, and has yet to be available in the mainstream to a significant degree.
Bass Management Controllers
Fortunately, a few visionary companies have foreseen the problems that the advent of DVD-Audio has presented, and have stepped up to the plate to address them. One such company is Outlaw Audio (
www.outlawaudio.com), the makers of the well-received ICBM, which stands for integrated controlled bass manager. I'm going to discuss bass management via the ICBM simply because I own one, but my comments should mostly apply to similar units from other companies.
The ICBM and its ilk are single function devices that sit between your DVD-Audio player and your receiver, and provide the bass management function that your receiver and DVD-Audio player do not. In the case of the ICBM, at least, its bass management is far superior to that of most A/V receivers on the market today. Basically, as shown in Figure 3, the 6 analog channels that carry the DVD-Audio signal come out of the back of your DVD player and connect to the corresponding channel inputs on the ICBM. You must connect another set of 6 cables from the outputs of the ICBM to the corresponding external inputs on your processor or receiver. So while this setup requires an additional set of 6 cables, it also provides you with the all-important bass management function, which is now handled by the ICBM (or whatever bass management controller you may have). One of the really nice features about getting your bass management handled by ICBM is that you now can fine-tune the bass redirection to the specific needs of your system. Most processors and receivers have just a few fixed crossover points that are applied to any speaker depending on whether it is designated as large, medium, or small. Usually, the speakers set to large get all of the deep bass in a channel, whereas the speakers designated as small don't get any bass below 80 Hz. These fixed crossover points (the points at which signals are divided for bass redirection) may not be optimal for the speakers in your system. Your front speakers may do a great job with bass content at or above 40 Hz, but may not be suitable at 20 Hz. Your small rear surround speakers may actually not be able to do justice to bass content at 80 Hz, so you may need to set the crossover for them higher. Also, it is likely that your center channel will have yet different low-frequency limitations than both your fronts and rears, meaning that it may need its own crossover point. Fortunately, the ICBM provides you with the capability to independently set the crossover points for the fronts, center, and rears, which is a big plus, and represents an even better solution than what is typically provided for bass management in Dolby Digital and DTS systems.
As you can see, these new bass management controllers have provided a trump card for DVD-Audio, for now it is possible to have superior bass management in your DVD-Audio setup, whereas before, there was none, unless you own certain high-end components.
Summary
Keep in mind that its is entirely possible to enjoy a DVD-Audio title on a system that has a typical DVD-Video player and a Dolby Digital/DTS receiver. As stated earlier, most titles provide, as supplemental material, multi-channel sound tracks in either Dolby Digital or DTS form. This makes is possible to own your favorite music in a rich multi-channel format and then later upgrade your system, while having your music collection take advantage of that upgrade. As I see things, you have two options to enjoy DVD-Audio beyond what you get with the typical DVD-Video system.
If your system includes 5 good quality, full-range speakers, in addition to a subwoofer, then you simply need the following items:
A DVD-Audio capable player,
A DVD-Audio ready receiver or processor (with 6 external analog inputs),
6 high-quality interconnect cables,
DVD-Audio titles.
If your system includes smallish main speakers and/or bookshelf sized speakers that can't accurately reproduce signals down to 20 Hz, then to fully take advantage of the high-resolution sound that DVD-Audio has to offer, the additional items you need, beyond the list above, are:
A bass management controller, such as the Outlaw Audio ICBM,
6 additional high quality interconnect cables (making 12 in total).
If you own a basic DVD-Video system with a Dolby Digital/DTS receiver that has the necessary inputs, you can make the jump to DVD-Audio in steps. If you don't want to purchase a DVD-Audio capable player right off, you can still buy some titles because most of them include a Dolby Digital or a DTS track (read the packaging carefully to be sure) that you can enjoy on your current equipment. However, if you've got some money to spend, then your first step would be to acquire a DVD-Audio player and 6 interconnect cables. If you have 5 good full-range speakers and a subwoofer, you're done, and you can start fully enjoying DVD-Audio titles. Later, assuming you are unwilling to upgrade your speakers (which would be unnecessary anyway), you can acquire a bass management controller, like the ICBM, along with another 6 interconnect cables. At this point your system would be fully capable of DVD-Audio playback without fear of damaging small speakers, listening to distorted sound, or missing the full acoustic content in your material.
DVD-Audio is ushering in a new era in high-quality, high-resolution audio entertainment. Not since the introduction of CD many years ago have we, the consumer, been able to reap the benefits of a truly superior sound format. And to think, we can all look at the amazing thing known as DVD as the primary reason for this progress.
http://www.dvdangle.com/dvd_audio/upgra ... _dvda.html
Now your guns are locked and loaded and ready to go..start blazing the trail!!