what's better, dd/dts decoders in dvd player or receiver??

Discussion in 'Archived Threads 2001-2004' started by Ben Hanrahan, Feb 14, 2002.

  1. Ben Hanrahan

    Ben Hanrahan Stunt Coordinator

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    I would like to sparc this debate because I feel strongly about it and I don't think many of you even consider it. The fact is that newer dvd players with built in decoders will sound much better hooked up with the analogue outputs hooked up to the 6 channel ins of your receiver rather than hooked up with an optical cable. If you use an optical cable, your doing 2 digital to analogue conversions which adds significant jitter to your audio signal, furthermore the dac's in the new Panasonic players are more than likely better than what's in your receiver. I witnessed this first hand at a local stereo store where we were switching on the fly between the dvd's dac and the receivers dac, much warmer sound coming from the dvd player's dac, more of a harsh upper frequency range coming from the receivers dac. Anybody agree? Disagree?

    Ben
     
  2. John Tompkins

    John Tompkins Supporting Actor

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    Quote:
    "If you use an optical cable, your doing 2 digital to analogue conversions which adds significant jitter "
    Ben, If you are using the optical out of your dvd player, wouldnt you just be doing one d/a conversion since its sent digitally to the receiver and then the receiever does the d/a conversion..I think
    Also I had the sony 555es sacd player with VERY good dacs for REDBOOK playback. I SLIGHTLY preferred the denon 4802 dacs in an a/b test..It could be the fact that the 4802 aligns all eight of its 24 bit dacs on to two channels, 4 dacs per channel in PURE DIRECT mode
    SACD was a totally different beast[​IMG]
     
  3. Philip Hamm

    Philip Hamm Lead Actor

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    As a general rule, it's better to have the processing in the receiver, where functions like bass management and time alignment are generally more configurable. Also, many people like DSP modes like EX and such that create a center matrixed rear or two using digital signal processing. However, assuming that we are listening to a 5.1 source with a conventional 5.1 system you have a very good point, particularly for SACD and DVD-A machines that have very high quality 5.1 digital processing and top notch analog outputs. In those cases it would be wise to compare the sound of both the receiver's 5.1 processing and the player's 5.1 processing and see what sounds better.

    In my system the DD and DTS decoding is noticably better in my pre/pro than in my high quality DVD-A player. However, I know that because I did not assume that the receiver would sound better and did some listening both ways and switched back and forth.

    BTW, John is right, there is no additional D/A step involved in the digital connection, it's just that the D/A is done by a different processor.
     
  4. Ben Hanrahan

    Ben Hanrahan Stunt Coordinator

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    I hope someone else can chime in here, isn't the digital data (1's and 0's) sent in an analogue format somehow??? I admit that I am not sure in this case, but I would like to straighten this out once and for all. How is jitter introduced in dvd players then?? I doubt that jitter has anything to do with your receiver.

    Ben
     
  5. Philip Hamm

    Philip Hamm Lead Actor

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    Jitter has nothing to do with DD and DTS sound, only older PCM formats.

    The digital connection, whether optical or coaxial, is digital. The 0s and 1s are transferred atraight from the disc to the receiver or pre/pro where the digital to analog conversion occurs.
     
  6. Paul Clarke

    Paul Clarke Supporting Actor

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    A lot also depends on the receiver. If older in technology, the preferred method would then be to use the analog from the DVD player, especially if DVD-Audio capable. I tried this on an older JVC receiver I still have around (884BK) and the 70BK DVD player DAC is far superior as you might expect even on two channel analog. There is a noticeable volume drop with digital input (haven't measured it in db yet) to boot.
    My H/K 510 though is a whole other story. [​IMG]
     
  7. Michael Reuben

    Michael Reuben Studio Mogul

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  8. Dzung Pham

    Dzung Pham Second Unit

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    I'm not sure if it is a fact that jitter does not effect DD or DTS. Check out a couple of threads on this controversy here and here. In particular, take a look at the posts by Thager in the first thread. He's a Dolby Labs engineer and says that jitter (in theory) can effect DD or DTS.
    As for Ben's question, I think the sound quality will depend on the quality of the player vs. the receiver. But the flexibility of the receiver in terms of bass management, time alignment, and other processing usually wins out.
     
  9. WesleyHester

    WesleyHester Stunt Coordinator

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    I like BOTH the DVD player and the receiver to have Dolby Digital/DTS decoders just as a backup.

    That "backup" finally paid off big time when I got the Onkyo TX-DS797 receiver and it was discovered that the Dolby Digital tracks on Jurassic Park III; Atlantis: The Lost Empire and Pearl Harbor had audio drop out due the incompatibility between new flags produced by new Dolby authoring software and the new decoders in the Onkyo and other brand receviers.

    I only had to switch to Multichannel Input on the receiver (already set the DVD player's reference setting) and I had the Dolby Digital track WITHOUT drop outs. The DVD player's "older" decoder had no problem with the new encoding flags.

    I personally feel, especially with newer DVD players AND receivers, the sound quality with 5.1 analog can be quite good despite the extra D/A, A/D conversions. Peforming a quick A/B comparison between the two repeatedly, I almost could not tell the difference. They sound slightly different from one another but don't get me wrong: NO one sounded BETTER than the other, just ever so slightly different.

    Since the DVD player has a DTS decoder too, I tried it and got about the same results.

    Will everyone NEED this? No. Is it good just to have the option available, the added flexibility and worth the extra price? I think so.
     
  10. Philip Hamm

    Philip Hamm Lead Actor

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    Wesley,

    Well said and welcome to the forum. However, if you're using the 5.1 direct ins, then there should be no additional A/D and D/A involved. Just a nice clean signal.
     
  11. JeromeS

    JeromeS Stunt Coordinator

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    I've have both analog and digital coax from my Panasonic RP-91 to my Yamaha HTR-5250 and one thing I've notice is there is a slight difference in the decoding between the reciever and the dvd player. For example on M*A*S*H Season One, the dvd player will play most of the dialogue from the center whereas my reciever will have some sound from the L/R speakers also. I can only attribute it to the fact that the reciever is older.
     
  12. Philip Hamm

    Philip Hamm Lead Actor

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    Jerome,

    It sounds like you're getting a DD1.0 signal there. Through the 5.1 ins the only audio will come from the center channel. Through the digital connector it appears that your receiver is either decoding it as stereo DPL sednding lower freqs through the mains or apply some other kind of processing that sends the info to the mains.
     

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