Results 1 to 14 of 14
  1. #1
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826

    Dolby improves the sound of Bluray...sort of

    On Friday evening I had the opportunity to visit Dolby Labs to hear their newest technology Dolby Atmos, and Dolby TrueHD 96k. This is my second time hearing Dolby Atmos 13.1 for the professional theaters, so I was much more interested in Dolby TrueHD 96k.

    Just a background on TrueHD 96k, what Dolby does is upsample the 48khz sample rate of Bluray soundtracks to 96khz during encoding. The reason it is done this way, is because using a native 96khz sample rate for encoding takes up a lot of disc space which could effect video quality. By upsampling during encoding, not much additional space is taken up on the disc, which means nothing is taken from the bit rate of the video. By upsampling to 96khz, the anti aliasing filters have more gentle roll off the falls at 48khz, and eliminates the brickwall filters at 24khz. Dolby has liscensed Meridians Digital Audio new "Apodizing" filter which reduces an effect call pre-ringing which is supposed to give the audio more clarity. Pre-ringing causes digital audio to sound hard and harsh, and this filter reduces and even eliminates that harshness and hardness - making the audio sound more clear and natural. At least that are the claims.

    Dolby's company theaters are the best in the business, second only to Disney's and Sony screening and home theater rooms. The system is top notch, and extremely well calibrated, so I was really looking forward to this.

    Some clips were loaded on a computer, and these clips include 'The Lost Bladesmen', 'The Dark Knight', 'Kung Fu Panda', 'Flowers of War'. I was also given a Bluray disc of the San Francisco Orchestra at 100, a disc that commemorates the Orchestra's 100 year anniversary.

    In previous demonstrations, the Dolby guys told the listeners what to listen for, and there were visual cues when the upsampling filter was on and off. I asked if they would not do this, as I know the power of suggestion, and how one can be manipulated into hearing something they might not otherwise notice,
    With that, the lights went down, and the demo began.

    Was Dolby demo a success? Well sort of. All of the clips sound really good, and I mean really good. However, the difference between the upsampled sound, and the standard sample clips was so subtle I could barely detect the difference. Sometimes I could not hear any difference at all! The upsampling process did not harm, but I am not sure it did that much good either. Consider me a skeptic on this one. Perhaps in a smaller room where we are closer to the speakers, I will hear a difference. I am willing to give this technology another chance under different conditions.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  2. #2
    Forum Regular Woochifer's Avatar
    Join Date
    Dec 2001
    Location
    SF Bay Area
    Posts
    6,883
    Count me among the skeptics on this one. Sounds like a nice refinement, but hardly anything that will make or break the sound quality. I'm all for higher res audio, and bringing the data streams as close as possible to the master source. But, upsampling a 48 kHz signal to 96 kHz is not the same thing as the real thing.

    I understand the need to conserve disc space, especially with video content taking priority, but doesn't DTS HD Master Audio already encode the audio at 96/24 resolution?
    Wooch's Home Theater 2.0 (Pics)
    Panasonic VIERA TH-C50FD18 50" 1080p
    Paradigm Reference Studio 40, CC, and 20 v.2
    Adire Audio Rava (EQ: Behringer Feedback Destroyer DSP1124)
    Yamaha RX-A1030
    Dual CS5000 (Ortofon OM30 Super)
    Sony UBP-X800
    Sony Playstation 3 (MediaLink OS X Server)
    Sony ES SCD-C2000ES
    JVC HR-S3912U
    Directv HR44 and WVB
    Logitech Harmony 700
    iPhone 5s/iPad 3
    Linksys WES610



    The Neverending DVD/BD Collection

    Subwoofer Setup and Parametric EQ Results *Dead Link*

  3. #3
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Thanks for the update, Sir T. But I'm a bit confused.

    I'm wondering though if Dolby TrueHD is sometimes recorded at a native 96 kpbs?

    According to Wikipedia, (here), Blu-ray supports Dolby TrueHD (lossless) at up to 24/96 for 8 channels or 24/192 for 5 channels. But is are these the non-upsampled rates? And if our players report 24/96 is there any way to know if this is native or upsampled?

  4. #4
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826
    Quote Originally Posted by Woochifer View Post
    Count me among the skeptics on this one. Sounds like a nice refinement, but hardly anything that will make or break the sound quality. I'm all for higher res audio, and bringing the data streams as close as possible to the master source. But, upsampling a 48 kHz signal to 96 kHz is not the same thing as the real thing.

    I understand the need to conserve disc space, especially with video content taking priority, but doesn't DTS HD Master Audio already encode the audio at 96/24 resolution?
    All Bluray soundtracks are sampled at 48khz. Here is what I suspect. Dolby TrueHD is basically disappearing off the Bluray format in favor of Dts HD Master audio. This is a chance for Dolby to reverse this trend by market differentiation - or to leave the impression that somehow Dolby TrueHD is a better codec than Dts's using this process. They make the claim that this process of upsampling will make TrueHD sound better than the master file itself via the Apodizing filter inserted in the encoding process during upsampling. My experience suggests the process is much too subtle to make a difference to most folks. Using this analogy, I was hoping for the grunge to be entirely scrapped away from the window, and what I saw was something every so slightly less grungy one would not notice.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  5. #5
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826
    Quote Originally Posted by Feanor View Post
    Thanks for the update, Sir T. But I'm a bit confused.

    I'm wondering though if Dolby TrueHD is sometimes recorded at a native 96 kpbs?

    According to Wikipedia, (here), Blu-ray supports Dolby TrueHD (lossless) at up to 24/96 for 8 channels or 24/192 for 5 channels. But is are these the non-upsampled rates? And if our players report 24/96 is there any way to know if this is native or upsampled?
    Feanor, you are confusing the data rate with the sample rate. The sample rates you list are native sample rates, not upsampled rates. Those rates are established during production, and the process Dolby has come up with is done post production, and during encoding.

    The upsampling process regardless of whether it is done on the disc, or within the player introduces something called pre-ringing or some other artifacting. The Apodizing filter eliminates the pre-ringing, but I am not sure there is enough pre-ringing occurring in the production of soundtracks to make a huge difference - hence why the effect I heard was so subtle it could be unnoticeable.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  6. #6
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by Sir Terrence the Terrible View Post
    Feanor, you are confusing the data rate with the sample rate. The sample rates you list are native sample rates, not upsampled rates. Those rates are established during production, and the process Dolby has come up with is done post production, and during encoding. ...
    So ... by the time they get to the disc native and upsampled 96 look the same.

    Quote Originally Posted by Sir Terrence the Terrible View Post
    ...
    The upsampling process regardless of whether it is done on the disc, or within the player introduces something called pre-ringing or some other artifacting. The Apodizing filter eliminates the pre-ringing, but I am not sure there is enough pre-ringing occurring in the production of soundtracks to make a huge difference - hence why the effect I heard was so subtle it could be unnoticeable.
    I'm heard of the pre-ringing issue which, in the simplest terms, is a response in the upsampled bitstream that precedes the actual transient the bitstream is supposed to be representing. I don't pretend to understand why this happens. People proposed that this signal-before-the-signal is audible and disagreeable.

    I've also heard about "apodizing" filtering that reduces or eliminates pre-ringing, but I assure you I don't fully understand this either.

  7. #7
    Shostakovich fan Feanor's Avatar
    Join Date
    Jun 2002
    Location
    London, Ontario
    Posts
    8,127
    Quote Originally Posted by Sir Terrence the Terrible View Post
    All Bluray soundtracks are sampled at 48khz. ...
    Really? Is this just the practice or is it theoretical limitation?

  8. #8
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826
    Quote Originally Posted by Feanor View Post
    So ... by the time they get to the disc native and upsampled 96 look the same.
    Actually a 96khz native sample rate can potentially have high frequency information up to 48khz before it hits the brickwall filter. 48khz upsampled to 96khz will have no information above 24khz, but the filter has been moved from 24khz to 48khz. So upsampling is not adding information, it is just moving the brickwall filter up an octave. If done correctly, there will be added air, and a sense of smoothness to the audio.


    I'm heard of the pre-ringing issue which, in the simplest terms, is a response in the upsampled bitstream that precedes the actual transient the bitstream is supposed to be representing. I don't pretend to understand why this happens. People proposed that this signal-before-the-signal is audible and disagreeable.

    I've also heard about "apodizing" filtering that reduces or eliminates pre-ringing, but I assure you I don't fully understand this either.
    With the high ambient levels of most homes, I seriously doubt you can hear the pre-ring filter directly. But you can hear its effects pretty clearly as a hardening and coarsening of the sound. To me it sounds like what you hear with Dolby Digital when it is bit challenged.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  9. #9
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826
    Quote Originally Posted by Feanor View Post
    Really? Is this just the practice or is it theoretical limitation?
    Actually the Bluray format supports 8 channels of 24/192khz audio. However the post production community workflows are limited to 48khz because of the amount of resources any higher sample rate takes up. For instance, If I have 24 channels of 48khz audio, I can only have 12 channels of 96khz audio because it takes twice as much data and resources to work with it.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  10. #10
    Music Junkie E-Stat's Avatar
    Join Date
    Dec 2003
    Posts
    5,462
    Quote Originally Posted by Sir Terrence the Terrible View Post
    Just a background on TrueHD 96k, what Dolby does is upsample the 48khz sample rate of Bluray soundtracks to 96khz during encoding.
    Does this allow for using the existing Dolby True HD codec found in processors today? Or, will this require a new one?

  11. #11
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826
    Quote Originally Posted by E-Stat View Post
    Does this allow for using the existing Dolby True HD codec found in processors today? Or, will this require a new one?
    This is a encoding process(and the brains of both formats codecs is in the encoder) so it will not require any changes or new decoder.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  12. #12
    Music Junkie E-Stat's Avatar
    Join Date
    Dec 2003
    Posts
    5,462
    Quote Originally Posted by Sir Terrence the Terrible View Post
    This is a encoding process(and the brains of both formats codecs is in the encoder) so it will not require any changes or new decoder.
    Cool, thanks.

  13. #13
    Suspended
    Join Date
    Oct 2005
    Posts
    928
    Quote Originally Posted by Sir Terrence the Terrible View Post
    Dolby's company theaters are the best in the business, second only to Disney's and Sony screening and home theater rooms. The system is top notch, and extremely well calibrated, so I was really looking forward to this.
    What hardware is Sony running in their screening and HT rooms. We disassembled our three A/V authoring suites here in Indiana and moved a lot of the good hardware to California and New York. We sent many Genelec powered monitors and subs, Tannoy and Dunlavy SCIV speakers. A lot of Music Fidelity and Sonic Frontiers processors, expanders, D/A converters, ... I'm just curious what they run in the screening rooms for playback.

  14. #14
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
    Join Date
    Jul 2002
    Posts
    6,826
    Quote Originally Posted by bfalls View Post
    What hardware is Sony running in their screening and HT rooms. We disassembled our three A/V authoring suites here in Indiana and moved a lot of the good hardware to California and New York. We sent many Genelec powered monitors and subs, Tannoy and Dunlavy SCIV speakers. A lot of Music Fidelity and Sonic Frontiers processors, expanders, D/A converters, ... I'm just curious what they run in the screening rooms for playback.
    I think mostly all of the studios(with the exception of Disney) use Genelec's in their HT rooms, and JBL speakers in their screening rooms. We(Disney) use Revel in our HT rooms, and a custom design (by the same guy that built the system in my sig) for our screening rooms.

    I would imagine all of that equipment you sent to California is probably heading to your gaming division in Redwood City. From what I understand, audio wise, that is where the action is.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •