DD + (HD-DVD) on older gear?

Discussion in 'AV Pre-Amp/Processors & Power Amps' started by badbob, Dec 23, 2006.

  1. badbob

    badbob
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    Is it possible to use a new HD-DVD player with older Dolby Digital/DTS processors, such as Lexicon MC-1 and DC-2? If so how is the bitstream handled when using non DD + capable equipment? Will the DVD player downsample on the fly to Dolby Digital, or do HD-DVD titles also include standard bitrate DD audio?

    Also what bitrates do standard Dolby Digital support, I know DTS is 1.4mb/sec and Toy Story is 384/kb sec, usually others are 480/kb sec, but is a higher bitrate possible, if so could HD DVD contain these, as might as well benefit from highest bitrate support on standard DD.
     
  2. Nic Rhodes

    Nic Rhodes
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    The HD DVD player encode the new formats (DD+, True HD) to full bit rate DTS (1.4mb) which can be decoded by 'older' processors.
     
  3. sinizterguy

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    Dont you mean decoded?
     
  4. jackal

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    Nic, is it not the case that an optical or coax digital connection can only pass a maximum bitrate of 640Kbps?
     
  5. Nic Rhodes

    Nic Rhodes
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    640 limit is for DD only. However many DD chip set struggle with this (see Pulse threads). They have issues with 640 due to technical problems, hence most DD is 440 or 380. DTS has always been capable of 1.4mbs rate hence the awesome sound of DTS laserdiscs (and a few full bit rate DVDs).
     
  6. Nic Rhodes

    Nic Rhodes
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    Typo. fixed, christmas cheer.:D
     
  7. ripclaw

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    I stand to be corrected, but you can also use the analog-outputs from an HD-DVD player and connect this to a receiver that has a 5.1 / 7.1 multichannel input.
     
  8. Mr_Sukebe

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    Yep, you certainly can, which extends the options. So you can:
    1. Take a DTS output using say Coax digital output from a BD/HD-DVD player to your existing unit.
    2. Use an analogue output from a HD-DVD player. HD-DVD players also support the new DD/DTS-HD/MA codecs, meaning that they're lossless.
    3. Use an analogue output from a BD player. BD players (not including the PS3) support LPCM, which is non-compressed, lossless 5.1 channel audio.

    Which would be best, will depend upon how good the existing kit is. I believe that max rate DTS uses a 1.5:1 compression ratio, so probably won't be massively different to a lossless version. Through something like a Lexicon or Meridian processor, I'd guess the improvements in DAC/analogue output stages would more than make up for the data loss.
     
  9. crobo

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    I am no expert on this but I just played my first couple of HD-DVDs through my Meridian 561 using the coax input. The display does show DTS coming through. I thought the sound was phenomenal - is this simply because it is high bitrate DTS? Anyone else have ideas about how much the signal is being compressed? I'm very interested in this point because I'm toying with the idea of a different processor with 5.1 analogue inputs for TrueHD. I won't worry so much if what I'm hearing is DTS of almost the same quality.
    Cheers
     
  10. musicman1999

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    The new DD/DTS codecs,while lossless are still compressed.The uncompressed LPCm should be best,so if your processor has 5.1 analog inputs that is the way to go.

    bill
     
  11. jackal

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    Lossless is lossless.

    DolbyTrueHD/DTS HD Master are simply more space efficient than uncompressed LPCM. Also the lossless packeting of DolbyTrueHD / DTS HD Master Audio have an inbuilt resistance to audio jitter which Blu Ray LPCM does not.

    In reality there should be little difference between the them.

    Both are output at 96Khz 24 bit which should be identical to the studio master.
     
  12. musicman1999

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    Compressed is still compressed.Do you hear a difference between DD and DTS,the difference is in the compression.Uncompressed pcm will give better than cd quality sound from every speaker.

    bill
     
  13. Nic Rhodes

    Nic Rhodes
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    TrueHD and MA are bit for bit idential to PCM but just use less space on the disc.
     
  14. Mr_Sukebe

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    As I understand it, DD is compressed at a 12:1 ratio, DTS is variable, between 1.5:1 and 15:1. From what I've read, the output will be using the max DTS bandwidth, which is therefore a 1.5:1 ratio, so only throwing away a third of the data.

    With regard to LPCM vs HD-DTS et al. All of these are LOSSLESS, regardless of whether or not they're compressed, meaning that they're NOT like MP3s and haven't had "supposedly unimportant" data thrown in the bin.
    As already stated, the key differences are that LPCM is not compressed, thus taking up a whole lot more space on the disk.

    As I understand it, HDMI doesn't offer clock timing locks between kit, meaning that LPCM not being as resilient to jitter is probably irrelevant (even more so if you're using the analogue outputs).
     

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