I can hear TrueHD on a very old B&K Pre-Pro-perhaps?

Discussion in 'Playback Devices' started by Nelson Au, Nov 3, 2007.

  1. Nelson Au

    Nelson Au Executive Producer

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    I thought this might be the better place to post this observation about TrueHD audio from an HD-DVD decoded on a 10 year old Pre-Pro. This is new to me, so perhaps this is old hat to many of you.

    I just bought the Toshiba HD-A35. It's the first HD-DVD player for me and the first new player in 7 years. It's hooked up to a Plioneer Plasma so I am getting 1080i imagery and it's beautiful!

    I only have 3 HD-DVD's, The Bourne Identity, 2001 and 300. I just got a Toslink optical cable for the audio and my observation so far have been amazing audio from Bourne and 2001.

    After a making a few attempts, I finally got audio into the Pre-Pro via bitstream. PCM wasn't being accepted by the processor. What surprised me is that the Warner DVD of 2001 defaults to TrueHD audio. When I first got this stuff, my understanding is that my 10 year old B&K Processor could only take the audio that is downconvert to DTS. What is happening is the Dolby Digital Plus is being read and decoded as AC-3 by my processor and it sounded great in Bourne. But 2001 was a real treat. The processor actually appears to be accepting the TrueHD audio! And I tried the DTS setting in my processor, no sound, so it appears to be getting Dolby Digital.

    As an unscientific test, I used an SPL meter to check the sequence when the teams walks into the excavation site near the Clavius crater to see the Monolith. I set the player to output in Dolby Digital Plus. The music there was pretty terrific, but when I set the player to TrueHD, the SPL levels jumped 5 to 8 decibels. It sounded louder. Did I hear a difference? Maybe, maybe not. But I liked it better in TrueHD. Though I realize this is not really TrueHD I'm hearing.

    Since Bourne is only Dolby Digital Plus, it sounded great too, but was lower in volume. I am really curious now to get Top Gun or another disc that is TrueHD audio to compare. I am not crazy about seeing 300, but I suppose I'll check it out.

    Anyone have similar experiences with other hardware decoding the audio? Maybe this is not so amazing? I am just surprised that it appears TrueHD is decoding, although a likely a crippled or detuned version. I didn't expect this![​IMG]
     
  2. Shane Martin

    Shane Martin Producer

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    You arent' getting true HD. True HD can only be passed via HDMI or analog. If you use optical then the player is converting it to DTS.
     
  3. Nelson Au

    Nelson Au Executive Producer

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    Yes, I ain't getting TrueHD, but it was fun for a while to think I could have some kind. [​IMG]

    What I don't understand is the DTS part of the equation. If the player is downconverting to DTS, why my processor sees it as Dolby Digital.

    Doesn't matter I guess. For now I am happy to be getting some great sounding audio from the player and this old processor.
     
  4. brap

    brap Stunt Coordinator

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    I'm hooked up the same way using optical, but it's displaying DTS. Yours displaying as Dolby Digital is strange for an A2. Even though it is down converted, TrueHD will sound better that DD+ because the best results depend on the source. Encode a CD to MP3 and then re-encode a MP3 to an MP3. The mp3 from CD source will sound way better.
    When it comes to volume, higher on a track is not better. You can easily turn it up. A big boom will have less effect if the track is always maxed out loud because there will be no room in the volume for it to go. Clarity and nice bass is what matters.
     
  5. Nelson Au

    Nelson Au Executive Producer

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    brap- I have an A35, your post sounded like you thought I had an A2. Perhaps there's something new going on with the output of the A35, now it has Dolby Digital downmixes?
     
  6. brap

    brap Stunt Coordinator

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    Oops. my bad. Everything but the A2 still makes sense though. From everything I have read on the A35, it is supposed to only output DTS 1.5Mbps when using the new formats through optical.
     
  7. Jack Gilvey

    Jack Gilvey Producer

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    Sounds like the A35 is downconverting to legacy DD. The A2 downconverts to DTS, the idea being that the higher maximum bitrate of the DTS spec would better preserve quality, but many older DTS receivers had trouble with the high bitrate.
     

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