• 09-03-2007, 10:18 AM
    ForeverAutumn
    What's the difference between Dolby and DTS?
    Hubby and I were watching/listening to a Ronnie James Dio DVD this morning (now that the sub is working :) )and in the settings section we could choose between Dolby Digital 5.1 and DTS. We listened to both and we agreed that the DTS sound was superior. But we aren't tech savvy enough to know why they are different. Can anyone explain this to us in layman's term?
  • 09-03-2007, 10:27 AM
    kexodusc
    Quote:

    Originally Posted by ForeverAutumn
    Hubby and I were watching/listening to a Ronnie James Dio DVD this morning (now that the sub is working :) )and in the settings section we could choose between Dolby Digital 5.1 and DTS. We listened to both and we agreed that the DTS sound was superior. But we aren't tech savvy enough to know why they are different. Can anyone explain this to us in layman's term?

    Compression is the biggest difference. Dolby compresses the audio track about 3.5 times more than DTS when encoding the audio information digitally. Or put differently, DTS compresses (and loses) less of the original sound. Some of the information is deemed "unimportant" and is lost in both formats when compressed - DTS remains closer to the original waveform of the soundtrack. Just like a low mp3 bitrate basically, You may have noticed how 192k sounds better than 128k (etc). Same principle.

    I think Dolby actually has a smarter algorithm for compression, in that it does more with much less, but it still comes up short most of the time. If you can, always select DTS.
  • 09-03-2007, 02:24 PM
    ForeverAutumn
    That makes perfect sense. Thanks Kex!
  • 09-03-2007, 07:35 PM
    PeruvianSkies
    Quote:

    Originally Posted by ForeverAutumn
    That makes perfect sense. Thanks Kex!


    It's too bad that there aren't more DTS titles out there, if you notice my thread I started...

    http://forums.audioreview.com/home-theater-video/calling-dts-where-you-24044.html
  • 09-03-2007, 07:51 PM
    musicman1999
    I think the problem is that most people don't know the difference and don't care.The average
    guy puts the disc in and presses play,a lot of people don't even have surround,pump it to the tv and thats it.
    I pick DTS when available but if its not there i am still going to buy the disc.I find that DTS has more detail and a better sense of air and soundstage but is also a little louder than DD.
    Of course with Bluray with uncompressed pcm things have gone to a new level.

    bill
  • 09-03-2007, 08:35 PM
    PeruvianSkies
    Quote:

    Originally Posted by musicman1999
    I think the problem is that most people don't know the difference and don't care.The average
    guy puts the disc in and presses play,a lot of people don't even have surround,pump it to the tv and thats it.
    I pick DTS when available but if its not there i am still going to buy the disc.I find that DTS has more detail and a better sense of air and soundstage but is also a little louder than DD.
    Of course with Bluray with uncompressed pcm things have gone to a new level.

    bill

    and that is because most DVD's default to DD 5.1, which is the real crime here...if all DVD's came with both audio options than the main menu should be setup in such a way that you decide which audio format, similar to the DVD's that have both widescreen and fullscreen menu options that pop up. If more people actually experienced DTS there wouldn't be any need for DD 5.1 because it's never as good as the DTS offerings. I'd take PCM over DD anyday!
  • 09-03-2007, 09:19 PM
    musicman1999
    But most people still would not know the difference even if they had to choose.A large number of people that have surround have only a $300 htib and that is all they will ever need,on those systems DD and DTS sound pretty much alike,that is awful to my ears anyway.
    I think,unfortunately, that DTS tracks will appear less and less due to lack of demand and the cost of having more than one 5.1 track.
    PCM is better than DD and DTS play a good concert DVD such as David Gilmour live,which has an outstanding DD track but the PCM kills it.The new Santana Hymns for Peace has all three and again PCM kills the other 2.

    bill
  • 09-03-2007, 09:40 PM
    PeruvianSkies
    Quote:

    Originally Posted by musicman1999
    But most people still would not know the difference even if they had to choose.A large number of people that have surround have only a $300 htib and that is all they will ever need,on those systems DD and DTS sound pretty much alike,that is awful to my ears anyway.
    I think,unfortunately, that DTS tracks will appear less and less due to lack of demand and the cost of having more than one 5.1 track.
    PCM is better than DD and DTS play a good concert DVD such as David Gilmour live,which has an outstanding DD track but the PCM kills it.The new Santana Hymns for Peace has all three and again PCM kills the other 2.

    bill

    2 things:

    1. Even on the cheap-o HTiB systems...I have still heard a difference that was justifiable enough to still pick DTS.

    2. One of the best PCM Audio tracks that I have heard is on the Cranberries DVD set of their music videos, which is one my highest recommended DVD's to own. The video for LINGER and the fantastic PCM is worth dropping a few bucks on it hands down!
  • 09-04-2007, 05:04 AM
    ForeverAutumn
    You know I have to ask...

    What is PCM?
  • 09-04-2007, 05:41 AM
    Feanor
    Pulse-code modulation
    Quote:

    Originally Posted by ForeverAutumn
    You know I have to ask...

    What is PCM?

    The basic digital encode strategy used by CD, DAT, DVD, DVD-A, etc. CD measures the sound to 16 bits precision at a frequency of 44.1kHz; DVD-A is 24 bits @ 96kHz or 192kHz which is a lot higher resolution.

    Read all about it here ...
    http://en.wikipedia.org/wiki/PCM

    I case you're worried about it, SACD employs quite different encoding technique called 'DSD', "Direct Stream Digital".
  • 09-04-2007, 08:39 AM
    hydroman
    Good info here! Thanks!
  • 09-05-2007, 06:13 PM
    Woochifer
    FA -

    The short of it might be that the DTS track was playing ~4 db louder than the DD track. But, there are other differences at work ...

    The similarity between Dolby Digital and DTS is that they are both compressed "lossy" formats. Conceptually, this is similar to how MP3 or AAC compress the data from a CD to ~1/12 of the original file size. PCM is a "lossless" format that's used for CD audio and the vast majority of professional digital recording. It's inherently less efficient, because all sounds consume the same amount of data, no matter how little of that data the audio signal will actually use. But, it represents the full uncompressed data. "Lossy" formats will discard data that's in the less audible ranges.

    The difference as others have pointed out is that DTS uses a higher data rate than DD. DTS has a standard data rate of 1.5k, and a more commonly used 768k half-bitrate version. By comparison, Dolby Digital has standard data rates of 448k and 384k for DVD, as well as a higher bitrate of 640k that was previously used with Laserdiscs and currently used with Blu-ray discs. 384k DD is also the standard 5.1 audio format for HDTV.

    For reference, audio CDs use a data rate of 1.5k for only two channels. DD and DTS are both cramming 5.1 (or in the case of DTS ES,6.1) channels into a considerably smaller bitstream. Two-channel MP3 files are typically encoded at a datarate of 128k to 192k.

    As far as comparisons between the two formats, I think the two biggest strikes against DD in direct comparisons are 1) high frequency channel joining and 2) dialog normalization.

    The high frequency channel joining is Dolby's technique of having the channels "share" high frequency information in order to conserve data space for other more audible sounds in lower frequencies. With 448k DD, sounds above 15 kHz are shared by all channels, which is not in the primary range of most music sounds. But, with 384k DD, the sounds above 10 kHz are shared by all channels, and here the channel joining is more audible and tends to make the surround imaging sound "fatter" and less distinct.

    The other feature of Dolby Digital that often puts it at a disadvantage in A/B comparisons is dialog normalization. This is a feature that purportedly standardizes the dialog level between different Dolby Digital sources. (see diagram below) The default value for Dolby Digital encoders is -4 db, and this is probably the most common value for DVD soundtracks. Since DTS does not use dialog normalization, it will almost always play back louder than the DD track (with a 4 db difference most common).

    http://www.hometheaterhifi.com/volum...tion-fig-2.gif

    http://www.hometheaterhifi.com/volum...tion-fig-3.gif

    http://www.hometheaterhifi.com/volum...on-6-2000.html

    Another factor to consider is that early on, all of the DTS encoding was done by DTS with their engineers. Often, the DTS encodes used higher resolution masters that were remixed, while the DD track would be transferred from the theatrical print master with no remixing or other reengineering. A good example of this is the Signature Selection DVD of Gladiator, where the DTS track clearly blows away the DD track. But, because the DTS track was first remixed and transferred using a higher resolution master, it was not exactly a fair comparison.

    I agree that DTS tracks will offer up at least subtlely better audio quality than DD most of the time. But, if you're doing level matched comparisons with sources known to have been transferred under comparable conditions (the Director's Cut series for Lethal Weapon was done this way), the differences between DD and DTS are not as huge as often touted.
  • 09-06-2007, 01:27 AM
    pixelthis
    Quote:

    Originally Posted by Woochifer
    FA -

    The short of it might be that the DTS track was playing ~4 db louder than the DD track. But, there are other differences at work ...

    The similarity between Dolby Digital and DTS is that they are both compressed "lossy" formats. Conceptually, this is similar to how MP3 or AAC compress the data from a CD to ~1/12 of the original file size. PCM is a "lossless" format that's used for CD audio and the vast majority of professional digital recording. It's inherently less efficient, because all sounds consume the same amount of data, no matter how little of that data the audio signal will actually use. But, it represents the full uncompressed data. "Lossy" formats will discard data that's in the less audible ranges.

    The difference as others have pointed out is that DTS uses a higher data rate than DD. DTS has a standard data rate of 1.5k, and a more commonly used 768k half-bitrate version. By comparison, Dolby Digital has standard data rates of 448k and 384k for DVD, as well as a higher bitrate of 640k that was previously used with Laserdiscs and currently used with Blu-ray discs. 384k DD is also the standard 5.1 audio format for HDTV.

    For reference, audio CDs use a data rate of 1.5k for only two channels. DD and DTS are both cramming 5.1 (or in the case of DTS ES,6.1) channels into a considerably smaller bitstream. Two-channel MP3 files are typically encoded at a datarate of 128k to 192k.

    As far as comparisons between the two formats, I think the two biggest strikes against DD in direct comparisons are 1) high frequency channel joining and 2) dialog normalization.

    The high frequency channel joining is Dolby's technique of having the channels "share" high frequency information in order to conserve data space for other more audible sounds in lower frequencies. With 448k DD, sounds above 15 kHz are shared by all channels, which is not in the primary range of most music sounds. But, with 384k DD, the sounds above 10 kHz are shared by all channels, and here the channel joining is more audible and tends to make the surround imaging sound "fatter" and less distinct.

    The other feature of Dolby Digital that often puts it at a disadvantage in A/B comparisons is dialog normalization. This is a feature that purportedly standardizes the dialog level between different Dolby Digital sources. (see diagram below) The default value for Dolby Digital encoders is -4 db, and this is probably the most common value for DVD soundtracks. Since DTS does not use dialog normalization, it will almost always play back louder than the DD track (with a 4 db difference most common).

    http://www.hometheaterhifi.com/volum...tion-fig-2.gif

    http://www.hometheaterhifi.com/volum...tion-fig-3.gif

    http://www.hometheaterhifi.com/volum...on-6-2000.html

    Another factor to consider is that early on, all of the DTS encoding was done by DTS with their engineers. Often, the DTS encodes used higher resolution masters that were remixed, while the DD track would be transferred from the theatrical print master with no remixing or other reengineering. A good example of this is the Signature Selection DVD of Gladiator, where the DTS track clearly blows away the DD track. But, because the DTS track was first remixed and transferred using a higher resolution master, it was not exactly a fair comparison.

    I agree that DTS tracks will offer up at least subtlely better audio quality than DD most of the time. But, if you're doing level matched comparisons with sources known to have been transferred under comparable conditions (the Director's Cut series for Lethal Weapon was done this way), the differences between DD and DTS are not as huge as often touted.

    And the main reason for this is that the one great advantage of DTS (a bit rate as high a 1.5 megabytes a second) isn't used!
    In order to save space they cut most DTS soundtracks to around 768 kbs, still better than most DD but not by as much, meaning that DTS has evolved into a marketing gimmick.
    For an example of what a DTS soundtrack can actually be listen to twelve monkeys
    (the movie, not peruvians family reunion) or Dances with wolves.
    BOTH HAVE EXELENT DTS soundtracks
  • 09-07-2007, 04:28 PM
    Woochifer
    Quote:

    Originally Posted by pixelthis
    And the main reason for this is that the one great advantage of DTS (a bit rate as high a 1.5 megabytes a second) isn't used!
    In order to save space they cut most DTS soundtracks to around 768 kbs, still better than most DD but not by as much, meaning that DTS has evolved into a marketing gimmick.
    For an example of what a DTS soundtrack can actually be listen to twelve monkeys
    (the movie, not peruvians family reunion) or Dances with wolves.
    BOTH HAVE EXELENT DTS soundtracks

    Well, I wouldn't call DTS a marketing gimmick because of the differences that I flagged in my post. Any format that doesn't use dialog normalization and doesn't do high frequency channel joining is already an improvement over DD.

    Granted, the differences between DD and DTS are misunderstood and exaggerated much of the time, but that does not mean that they don't exist. If the differences are real and verifiable (if the blind and level-matched listening tests cited by DTS as evidence of the format's transparency to the master source are to be trusted), then I wouldn't go referring to something as a marketing gimmick. Save that label for the overpriced cables and other dubious tweaks out there.

    And even at half bitrate, DTS is still a higher resolution format than DD. And without the half bitrate version, DTS would never have found its way onto more than a handful of DVD releases, and DTS would never have evolved into the universally supported format (on the hardware side) that it is today. If DTS had stuck only with the full 1.5k bitrate version, the format would have likely disappeared from the market altogether by now.
  • 09-07-2007, 09:34 PM
    PeruvianSkies
    Quote:

    Originally Posted by pixelthis
    And the main reason for this is that the one great advantage of DTS (a bit rate as high a 1.5 megabytes a second) isn't used!
    In order to save space they cut most DTS soundtracks to around 768 kbs, still better than most DD but not by as much, meaning that DTS has evolved into a marketing gimmick.
    For an example of what a DTS soundtrack can actually be listen to twelve monkeys
    (the movie, not peruvians family reunion) or Dances with wolves.
    BOTH HAVE EXELENT DTS soundtracks

    How about you take a listen to a full-bit rate DTS DVD and then tell me what kind of gimmick it is....
  • 09-08-2007, 12:35 AM
    pixelthis
    Quote:

    Originally Posted by Woochifer
    Well, I wouldn't call DTS a marketing gimmick because of the differences that I flagged in my post. Any format that doesn't use dialog normalization and doesn't do high frequency channel joining is already an improvement over DD.

    Granted, the differences between DD and DTS are misunderstood and exaggerated much of the time, but that does not mean that they don't exist. If the differences are real and verifiable (if the blind and level-matched listening tests cited by DTS as evidence of the format's transparency to the master source are to be trusted), then I wouldn't go referring to something as a marketing gimmick. Save that label for the overpriced cables and other dubious tweaks out there.

    And even at half bitrate, DTS is still a higher resolution format than DD. And without the half bitrate version, DTS would never have found its way onto more than a handful of DVD releases, and DTS would never have evolved into the universally supported format (on the hardware side) that it is today. If DTS had stuck only with the full 1.5k bitrate version, the format would have likely disappeared from the market altogether by now.

    True enough, and thanks for the knowledgeable post, BTW.
    I have spent so much time lately focusing on resolutions and such I completly forgot about dial normalization, in spite of the fact that it pops up on my receiver whenever
    its present.
    AND Peruvian, I have a DTS disc of Diana Krall, plays through the Toslink just like
    any other digital format.
    And yes it does sound quite amazing:21:

    And I am afraid that you misunderstand my statement about "marketing gimmick",
    that is the way DTS is being treated, and this great format deserves better than to be watered down. Take off the alternate soundtrack of some drugged out empty headed
    actress and increase the bitrate is what I am saying.
    One of my major gripes, and I think most would agree, is I buy movies to watch movies,
    get rid of some of these "special" features and give us some more quality hozabout?
    I really dont care about how a movie is made very much, when I buy a car I dont watch a video on how ITS made:thumbsup:
  • 09-08-2007, 04:27 AM
    kexodusc
    Quote:

    Originally Posted by pixelthis
    One of my major gripes, and I think most would agree, is I buy movies to watch movies,
    get rid of some of these "special" features and give us some more quality hozabout?

    Hear! Hear!
  • 09-08-2007, 07:23 AM
    L.J.
    Quote:

    Originally Posted by pixelthis
    One of my major gripes, and I think most would agree, is I buy movies to watch movies,
    get rid of some of these "special" features and give us some more quality hozabout?
    I really dont care about how a movie is made very much, when I buy a car I dont watch a video on how ITS made:thumbsup:

    :thumbsup:
  • 09-08-2007, 07:33 AM
    musicman1999
    Quote:

    Originally Posted by pixelthis
    One of my major gripes, and I think most would agree, is I buy movies to watch movies,
    get rid of some of these "special" features and give us some more quality hozabout?
    I really dont care about how a movie is made very much, when I buy a car I dont watch a video on how ITS made:thumbsup:

    Ditto

    bill
  • 09-16-2007, 09:53 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by Woochifer
    FA -

    The short of it might be that the DTS track was playing ~4 db louder than the DD track. But, there are other differences at work ...

    The similarity between Dolby Digital and DTS is that they are both compressed "lossy" formats. Conceptually, this is similar to how MP3 or AAC compress the data from a CD to ~1/12 of the original file size. PCM is a "lossless" format that's used for CD audio and the vast majority of professional digital recording. It's inherently less efficient, because all sounds consume the same amount of data, no matter how little of that data the audio signal will actually use. But, it represents the full uncompressed data. "Lossy" formats will discard data that's in the less audible ranges.

    The difference as others have pointed out is that DTS uses a higher data rate than DD. DTS has a standard data rate of 1.5k, and a more commonly used 768k half-bitrate version. By comparison, Dolby Digital has standard data rates of 448k and 384k for DVD, as well as a higher bitrate of 640k that was previously used with Laserdiscs and currently used with Blu-ray discs. 384k DD is also the standard 5.1 audio format for HDTV.

    For reference, audio CDs use a data rate of 1.5k for only two channels. DD and DTS are both cramming 5.1 (or in the case of DTS ES,6.1) channels into a considerably smaller bitstream. Two-channel MP3 files are typically encoded at a datarate of 128k to 192k.

    As far as comparisons between the two formats, I think the two biggest strikes against DD in direct comparisons are 1) high frequency channel joining and 2) dialog normalization.

    The high frequency channel joining is Dolby's technique of having the channels "share" high frequency information in order to conserve data space for other more audible sounds in lower frequencies. With 448k DD, sounds above 15 kHz are shared by all channels, which is not in the primary range of most music sounds. But, with 384k DD, the sounds above 10 kHz are shared by all channels, and here the channel joining is more audible and tends to make the surround imaging sound "fatter" and less distinct.

    The other feature of Dolby Digital that often puts it at a disadvantage in A/B comparisons is dialog normalization. This is a feature that purportedly standardizes the dialog level between different Dolby Digital sources. (see diagram below) The default value for Dolby Digital encoders is -4 db, and this is probably the most common value for DVD soundtracks. Since DTS does not use dialog normalization, it will almost always play back louder than the DD track (with a 4 db difference most common).

    http://www.hometheaterhifi.com/volum...tion-fig-2.gif

    http://www.hometheaterhifi.com/volum...tion-fig-3.gif

    http://www.hometheaterhifi.com/volum...on-6-2000.html

    Another factor to consider is that early on, all of the DTS encoding was done by DTS with their engineers. Often, the DTS encodes used higher resolution masters that were remixed, while the DD track would be transferred from the theatrical print master with no remixing or other reengineering. A good example of this is the Signature Selection DVD of Gladiator, where the DTS track clearly blows away the DD track. But, because the DTS track was first remixed and transferred using a higher resolution master, it was not exactly a fair comparison.

    I agree that DTS tracks will offer up at least subtlely better audio quality than DD most of the time. But, if you're doing level matched comparisons with sources known to have been transferred under comparable conditions (the Director's Cut series for Lethal Weapon was done this way), the differences between DD and DTS are not as huge as often touted.

    Boy,
    I wish I was as smart as you are my friend!

    I just wanted to add a bit to this great post. Until we have gotten to HDM on disc, there has not ever been a huge increase in audio resolution for film. They have always come in baby steps, and Dts is several baby steps up from DD.

    One of the most important things to consider is the goal of each of the encoders. Dolby's encoding goals are to reduce as much data as possible while maintaining good audio sound. Dts's goal is to process as much of the original PCM data as possible within its bit budget.

    Dolby achillies heel is not just dialog norm and channel joining. The worst offender in the Dolby process is global bit sharing. This is a process that moves bits from one channel to the next as the demands increases in that channel. The problem lies in the fact that with this kind of routine, you can often "starve" one channel to feed another, thereby reducing and often degrading sound quality in other channels.

    Another problem with DD is when all channels are pushed to the hilt, all of Dolby digital's channels become starved resulting in a hard midrange, and a ear shattering treble. When combined with the agressive data reduction technique, it makes this codec sound ragged at high sound levels with all channels engaged.

    Even Dolby had to agree that Dts at 1.5mbps is a well designed codec, and said as much in their sorry white paper that evaluates Dts. The great thing about this codec is the fact it can operate in a lossy mode, and in a lossless mode as well. Dts as the channel demands go down will go into a lossless mode, preserving all of the data intact without any data reducing techniques. Its reliance on perceptual encoding also decreases with the higher bitrate(Dolby's never does, and relies heavily on perceptual encoding). All of this allows Dts to preserve almost all the soundfield information(Dolby cannot), its Global bit allocation allows it to maintain channel seperation all the way past 19khz at 1.5mbps, and 15khz with 754kbps, which is why its percieved channel seperation is much better than Dolby's. Another advantage in Dts's favor is the phase between its LFE and bass in the main channels. Dts has just a 76 degree lead in the LFE at 80hz versus the main channels bass. This is why it has a tighter bass response . Dolby on the other hand has a LAG of about 225 degrees at 80, and increases gradually to its brickwall limit of 120hz. This often gives Dolby Digital a boomy quality to its bass because its is approximately 7 milliseconds behind in the LFE versus the main channels. In other words the bass smears which gives it a boomy, non distinct character.

    Another, and last great quality of Dts is its relevance as a core codec on both Bluray and HD DVD. Dts at 1.5mbps is the foundation to Dts HD MA. It was also used as a trancoding codec for HD DVD on Dolby trueHD decoding for the digital outputs. Dolby Digital at 448kbps has been relegated to second tier, if found at all. Dolby digital plus is just basic DD with extenstion data added, but the core process is the same. As Roger Dressler commented on at AVS, the real benefit of DD+ lies in lower bitrate processing, not higher bitrate processing. So DD+ will only sound marginally better beyond the core 640kbps bitrate. That is not the case for Dts.

    In the end both codecs sound very good for the amount of processing done at encoding. I think DD is a more efficient codec(which comes at a price in sonics), and Dts is very good at preserving all of the original data(which unfortunately takes up more space on disc). Performance wise, it is all Dts.

    Wooch, I have participated in Dts's double blind testing when I was at Paramount. It is indeed is as transparent as they say it is, which is why I am, and always have been a big fan of the Dts codec.

    By the way, hello everyone! Its been a long time since I last visited, and it is darn good to see the old regulars around still.
  • 09-16-2007, 11:08 AM
    L.J.
    Quote:

    Originally Posted by Sir Terrence the Terrible
    By the way, hello everyone! Its been a long time since I last visited, and it is darn good to see the old regulars around still.

    What's hangin' Sir T? It's good to hear from ya.
  • 09-16-2007, 11:40 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by L.J.
    What's hangin' Sir T? It's good to hear from ya.

    It's all good. So I see you went blu(as in bluray). Good choice, you should visit bluray.com every once in a while. Good info, good crowd, and lotsa interesting individuals. The insiders thread is excellent. Great information regarding the BDA, Sony, Disney(whom I represent) , replicators, BD-java, and chip manufacturers are well represented there. Its a good place to learn of future plans and releases of the studio's.
  • 09-17-2007, 05:14 AM
    GMichael
    Quote:

    Originally Posted by Sir Terrence the Terrible
    Boy,
    I wish I was as smart as you are my friend!

    I just wanted to add a bit to this great post. Until we have gotten to HDM on disc, there has not ever been a huge increase in audio resolution for film. They have always come in baby steps, and Dts is several baby steps up from DD.

    One of the most important things to consider is the goal of each of the encoders. Dolby's encoding goals are to reduce as much data as possible while maintaining good audio sound. Dts's goal is to process as much of the original PCM data as possible within its bit budget.

    Dolby achillies heel is not just dialog norm and channel joining. The worst offender in the Dolby process is global bit sharing. This is a process that moves bits from one channel to the next as the demands increases in that channel. The problem lies in the fact that with this kind of routine, you can often "starve" one channel to feed another, thereby reducing and often degrading sound quality in other channels.

    Another problem with DD is when all channels are pushed to the hilt, all of Dolby digital's channels become starved resulting in a hard midrange, and a ear shattering treble. When combined with the agressive data reduction technique, it makes this codec sound ragged at high sound levels with all channels engaged.

    Even Dolby had to agree that Dts at 1.5mbps is a well designed codec, and said as much in their sorry white paper that evaluates Dts. The great thing about this codec is the fact it can operate in a lossy mode, and in a lossless mode as well. Dts as the channel demands go down will go into a lossless mode, preserving all of the data intact without any data reducing techniques. Its reliance on perceptual encoding also decreases with the higher bitrate(Dolby's never does, and relies heavily on perceptual encoding). All of this allows Dts to preserve almost all the soundfield information(Dolby cannot), its Global bit allocation allows it to maintain channel seperation all the way past 19khz at 1.5mbps, and 15khz with 754kbps, which is why its percieved channel seperation is much better than Dolby's. Another advantage in Dts's favor is the phase between its LFE and bass in the main channels. Dts has just a 76 degree lead in the LFE at 80hz versus the main channels bass. This is why it has a tighter bass response . Dolby on the other hand has a LAG of about 225 degrees at 80, and increases gradually to its brickwall limit of 120hz. This often gives Dolby Digital a boomy quality to its bass because its is approximately 7 milliseconds behind in the LFE versus the main channels. In other words the bass smears which gives it a boomy, non distinct character.

    Another, and last great quality of Dts is its relevance as a core codec on both Bluray and HD DVD. Dts at 1.5mbps is the foundation to Dts HD MA. It was also used as a trancoding codec for HD DVD on Dolby trueHD decoding for the digital outputs. Dolby Digital at 448kbps has been relegated to second tier, if found at all. Dolby digital plus is just basic DD with extenstion data added, but the core process is the same. As Roger Dressler commented on at AVS, the real benefit of DD+ lies in lower bitrate processing, not higher bitrate processing. So DD+ will only sound marginally better beyond the core 640kbps bitrate. That is not the case for Dts.

    In the end both codecs sound very good for the amount of processing done at encoding. I think DD is a more efficient codec(which comes at a price in sonics), and Dts is very good at preserving all of the original data(which unfortunately takes up more space on disc). Performance wise, it is all Dts.

    Wooch, I have participated in Dts's double blind testing when I was at Paramount. It is indeed is as transparent as they say it is, which is why I am, and always have been a big fan of the Dts codec.

    By the way, hello everyone! Its been a long time since I last visited, and it is darn good to see the old regulars around still.

    Sir TTT? Is that really you? sniff sniff....

    I've missed you so much. Will you be sticking around for a little while? Can I get you some coffee or tea? How 'bout a muffin?
  • 09-17-2007, 06:14 AM
    Rich-n-Texas
  • 09-17-2007, 09:40 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by GMichael
    Sir TTT? Is that really you? sniff sniff....

    I've missed you so much. Will you be sticking around for a little while? Can I get you some coffee or tea? How 'bout a muffin?

    G,
    As much as my time will allow, I am back. I am helping out at Bluray.com right now, but I miss this place alot. My drum corps duties have kinda died down now that we are off season, and I have a little more time to hang out.

    I see you have been holding the place together.