DVDA (DVD Audio) & Surround Sound Information
WHAT IS DVDA?
DVDA is the first and most widely supported disc format for lossless high resolution stereo and multichannel (surround sound) audio. DVDA is delivered either as a standard DVD disc or electronically as a disc image file (xxx.iso). This document focuses on audio only. DVD is the most widely supported format for video as well. If designing a system for both audio and video, you will need to make appropriate choices for both.
WHAT IS HIGH RESOLUTION AUDIO AND SURROUND SOUND?
High resolution audio is superior to CD audio and refers to any resolution (number of samples in a second and the size or bit depth of each sample) above that of CD (44.1KHz, 16 bit). 96KHz, 24 bit is a commonly used size and is comparable in sound quality to a very high end vinyl system (like a $10,000 system with the best quality albums). Contrary to popular belief, CD audio doesn't come very close to this. CD is also limited to stereo (no surround). Surround sound refers to a system with 4 or more speakers surrounding the listener (front and back). Quadraphonic (4 speakers) was the first surround system in the early 1970's. Today the common format is 5.1 - front left, center and right and rear left and right speakers along with a subwoofer (lfe).
REQUIRED EQUIPMENT
A "home theater" system with 5 speakers and a subwoofer is required to listen to surround sound. An old-school 4 speaker quadraphonic system can be used for quad (4.0) program. You cannot listen to surround program with only 2 speakers. 2 speaker "surround simulations" or down-mixes generally don't work well; they don't resemble the original very much. There are 3 choices of 'media players' as follows. I recommend option 2 if starting from scratch but you may find the other options useful for existing equipment (that means without spending more money).
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PLAYER OPTION 1 - Old-school hardware DVD player
Compatibility:
Even though DVDA is the most widely supported surround format; format wars, paranoia over copy protection and budget line products have made it confusing and unaccessible to many. You need a DVD player that has high resolution digital converters and supports DVD Audio. Some budget machines will not play high resolution audio. No Sony machine will play high res audio from a DVDA disc as they compete with the format. If you ended up with one of these players, you will need to upgrade or switch to option 2 (see next) to eliminate these restrictions.
Required Equipment:
A hardware DVD player that supports DVD Audio discs.
Instructions:
MAC: Double click the .iso file to mount it to the desktop. Launch Disk utility. Select the mounted disk image. Click BURN.
WINDOWS: You will need to install an app to burn a DVD from a disk image (.iso file). ImgBurn is a free open source app for this. Select 'Write image file to disc', select the .iso file for the source and click 'write'.
Play the disk in your DVD player.
Pros: Easy to use when your media is supported.
Cons: Weird incompatibilities and disabled features depending on which formats are currently at war. Grossly overpriced for the quality of analog outputs typically found. Often riddled with copy protection schemes that degrade functionality and performance. No digital outputs for multichannel surround outputs.
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PLAYER OPTION 2 - Computer and audio interface
Compatibility:
Stereo playback (including high res) has strong support. There are a wide range of software media players to use. There are currently no media players for multichannel surround sound however - we're on the cutting edge here. You must use a DAW (digital audio workstation) application - the type of software used to mix multiple tracks of audio - to send the individual channels of audio to their respective speakers. This is not hard and requires no audio engineering skills.
Required Equipment:
An audio interface with at least 6 channels of output.
Required software:
DVD ripping app (DVDAExplorer is free open source)
DAW (digital audio workstation) app for multichannel playback
Equipment example:
The Presonus Firebox is a $160 option*. This has 6 balanced outputs and comes bundled with Cubase LE DAW software. Moving up the ladder, Apogee's are nice if you can afford them. Minimum specs should be 6 balanced analog outputs, firewire interface and 24 bit, 96KHz capable. You will not save much money by compromises like unbalanced outputs, fewer than 6 outputs or a USB interface (instead of firewire). Any DAW software will handle playback of 6 channels and most interfaces sold come with free software. Caution: At this time GarageBand and Cakewalk have high resolution (anything above 16/44.1) disabled; they're free for a reason and should be avoided.
Instructions:
Step 1: Mount the disk image
MAC: Double click the .iso file to mount it to the desktop.
WINDOWS: You will need to install an app to mount a disk image. WinCDEmu is a free open source app for this. Right click (control click) on the disc image file and choose 'Select drive letter & mount' from the menu.
Step 2: Rip the audio to wav files
You will need to install DVDAExplorer. This is an open source app available for both Mac & Windows.
In DVDAExplorer, browse to <mounted disc>/Audio_TS/AUDIO_TS.IFO and open it. Select the tracks to rip. Select the output directory and be sure to check the 'split groups' box for surround program (this gives you individual mono files for each speaker).
Step 3A: Set up a surround sound 'media player' with a DAW (this is initial setup the 1st time you run the DAW)
A DAW program lets you load the individual mono audio tracks that make up the surround program and send them to each appropriate speaker. This will be no different than loading stereo pairs of tracks into an audio editor other than more channels. There will be 6 channels for 5.1 surround and 4 channels for 4.0 quadraphonic. Note the first extension in the file name: L for Left front, C for Center, R for Right front, Ls for Left surround (rear), Rs for Right surround (rear) and Lf for Low frequency effects (subwoofer).
See your software manual but it will basically go like this:
You will need a 5.1 output in the DAW that is assigned to your audio interface. Take note of the channel assignments so you know which output is which on the interface. Add a 5.1 (or 4.0) audio track and assign it to the 5.1 output. Name the audio track "5.1 media" and the output master "5.1 main out".
*If using 5 full range speakers and subwoofer skip to step 3B*
*Bass management setup for 5 small satellite speakers and subwoofer*
If you have small satellite speakers you need to do what is called bass management. This is the process of routing the low bass frequencies from the 5 main channels to the subwoofer along with the Lf channel. Your subwoofer will not only be reproducing the Lf channel but also the low bass from the 5 main channels as well. You need to set this up on the DAW mixer. To do this you will need an additional 5.1 bus (with 5.0 and Lf subpaths available) and a mono bus. Add a 5.0 aux (named "main tops") and 2 mono aux tracks (named "Lf track" & "bass manage") and assign the outputs of all 3 to the 5.1 main output. Assign the 5.0 subpath (5.1 bus) to "main tops" input. Add an aux send to the mono bus on this track and send it to "bass manage". Set the input of "Lf track" to the Lf subpath of the 5.1 bus. Insert a high pass eq on "main tops" and a low pass eq on "bass manage". Set an identical sharp rolloff for both with the same frequency (depending on your speaker system this could be anywhere from 80 to 200Hz but is usually around 100 - 130Hz). Reassign the 5.1 audio track you 1st made to the 5.1 bus (not the 5.1 main out). Set all levels (media, main tops, the aux send, Lf & bass manage) to unity (0db).
You can now save this as a template to use for every 5.1 album. Save each 5.1 album as it's own session for easy recall.
Step 3B: Load tracks into DAW session
Load the surround tracks to the "5.1 media" track. See your DAW manual but usually if the extensions have the expected R,C,L,Ls,Rs,Lf you can just drag the group of tracks from a finder window to the DAW track edit window.
Step 4: Play the music
Pros: Best sound quality for the price (by a very wide margin). Fewer format restrictions. Ability to manage and backup your music collection.
Cons: Some software setup and a little learning curve required for surround sound.
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PLAYER OPTION 3 - Proprietary computer audio interface
Compatibility:
There are a few proprietary systems available for the computer. This type of system does NOT use standard audio protocol on the computer (ie. Core Audio). These systems consist of a PCI card and proprietary audio interface and software media player.
Required Equipment:
Proprietary audio interface
Required software:
included with interface
Equipment example:
Soundblaster products.
Instructions:
Step 1: Mount the disk image
MAC: Double click the .iso file to mount it to the desktop.
WINDOWS: You will need to install an app to mount a disk image. WinCDEmu is a free open source app for this. Right click (control click) on the disc image file and select 'Select drive letter & mount' from the menu.
Step 2: Play the music
Your media player will respond as though you just loaded a DVDA disc.
Pros: Easy to use with a media player style app for multichannel surround sound.
Cons: Does not use standard audio protocol on the computer. Not upgradable for future formats or better digital converters. Grossly overpriced for the quality of analog outputs typically found.
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A note about high resolution audio and consumer stereo equipment.
On a quality playback system, high resolution audio (eg. 24 bit, 96KHz) will sound stunningly better than CD audio (16 bit, 44.1KHz). I have found this scenario is going on with inexpensive consumer gear: CD's actually have a smaller dynamic (loudness) range than vinyl records (best case on high end gear). MP3's are even smaller by a magnitude. Consumer electronics eventually took advantage of this as these formats became popular. Since there were no longer big dynamics to reproduce, the quality of the analog outputs in consumer electronics was lowered considerably to save costs. The analog output circuits on some inexpensive gear are now so bad that you can tell no difference between high resolution audio and CD or even mp3.
The good news is that while the home stereo industry was working on new and bigger ways to suck and get away with it, the home recording industry started making interesting products (like the interface mentioned above) aimed at musicians. This allows you to build an extremely high quality sound system on a reasonable budget and take complete control of your music collection.
A note about speakers.
It goes without saying that you need reasonably good speakers to take advantage of high resolution audio. If you're on a budget, you should again turn to the home recording industry. A pair of KRK RP6 powered monitors ($320) will sound better than most speakers found at the consumer electronics store. This is as cheap as you should go if you're being half way serious. The quality of your system will depend on first the speakers and amps and next, the audio interface. If you're just starting out, 6 of the KRK RP6's plus a subwoofer and the Firebox would cost about $1300. An Apogee interface and 6 Genelec's and a sub would be... much more.
DISCLAIMER:
Any products mentioned by name are for example purposes only. I do not work for any of these companies or officially endorse any of these products. The information here is accurate to the best of my ability. Recommendations are based on available products and formats circa 2010 and my personal opinions. Please do your own research.
* Any prices mentioned are found by aggressively working eBay - you can always pay more.
I should mention this...
There's a reason you don't see configurations of equipment and computer as I've suggested sold at your local consumer electronics store. The record label "powers that be" absolutely panic at the sight of a computer. So the industry currently goes out of it's way to make things difficult. Rather than combat piracy however, this ends up preventing the delivery of these new and exciting audio formats to the consumer. I find the current "popular" options offered completely unreasonable for price vs performance.
Other formats:
Look for DTS HD Master Audio. This is lossless and would give the ability to have easily downloadable stereo files for surround tracks (as in 1 file per song). It is not currently being implemented in this way.
Blu Ray audio supports 8 channel (up to 7.1 surround) lossless. This format is just beginning to be available for the computer but progress is slow because its creator is against such development.