Confused with sample rates..help please!

Discussion in 'AV Receivers' started by BrettisMckinney, Jun 23, 2006.

  1. BrettisMckinney

    BrettisMckinney Second Unit

    Joined:
    Aug 25, 2002
    Messages:
    281
    Likes Received:
    0
    Trophy Points:
    0
    Ive been playing with HT for ages and though it might be an incredibly stupid question its something I havnt had to have any experience with. Basically what Im wondering is if you want to use 96kz for 2 channel audio, can that only be achievable over analogue? I ask this as I am using a DD sound card in my PC that you can select the output format..I can choose between 48kz or 96kz and the card is connected through a Digital Coax cable. When i select 96kz i dont get any sound though.

    Ive just put an audio cd into my dvd player running through the same amp and instead of using optical ive used 2 RCA's. In the dvd setup i selected 96kz and now it plays. Do I make any sense??
     
  2. JeremyErwin

    JeremyErwin Producer

    Joined:
    Feb 11, 2001
    Messages:
    3,218
    Likes Received:
    2
    Trophy Points:
    0
    Your receiver may not support 96 KHz PCM. Sampling rate is only applicable to a digital signal.
     
  3. BrettisMckinney

    BrettisMckinney Second Unit

    Joined:
    Aug 25, 2002
    Messages:
    281
    Likes Received:
    0
    Trophy Points:
    0
    Hmm ok..so its dependent on my reciever as to if it can recieve 96kz? But if i select 96kz on my DVD player it will play through reciever using analogue connections. Where as my PC wont using Digital Coax. What sample rate is DD 5.1 then? Or is the sample rate only for 2 channel?
     
  4. Steve Berger

    Steve Berger Supporting Actor

    Joined:
    Sep 8, 2001
    Messages:
    973
    Likes Received:
    3
    Trophy Points:
    110
    The setting on the DVD player is for passthrough of the digital bitstream to the receiver. A receiver might be able to do DD but not DTS on this stream or neither, or both; this depends on the receiver.

    There are legal constraints on inputs and outputs as well. These will be applied to standalone DVD players, receivers, CD players, MD player/recorders, DAT players/recorders but probably not PCs. On my Sony equipment, audio from an encrypted DVD (or a copyrighted CD) cannot be output at 96Hhz due to copyright restrictions. On my Receiver, only the DVD digital inputs will accept 96Khz; the CD, MD, and TV inputs are restricted to 48Khz max.

    In my case all of my equipment matches up and it all works OK because they all handle copyright limitations in the same manner. If you have mixed brands (or model years) you could see problems due to different interpretations of copyright restrictions. My only limit is to set the PC to 48Khz since it is using the "TV" input on my receiver since my HDTV tuner is in the PC.
     
  5. BrettisMckinney

    BrettisMckinney Second Unit

    Joined:
    Aug 25, 2002
    Messages:
    281
    Likes Received:
    0
    Trophy Points:
    0
    Wow..thats interesting. I dont see a reason why there would be restraints on sample rates..but I do believe it. In my case it seems the 2 channel DVD input on my reciever accepts 96kz but not the Digital Coaxial DVD input. That seems a bit strange to me. Unless it has something to do with the soundcard drivers
     
  6. Terry St

    Terry St Second Unit

    Joined:
    Jun 21, 2002
    Messages:
    393
    Likes Received:
    0
    Trophy Points:
    0

    If you select 96 kHz on your DVD player and hook it up via analogue connections then what is happening is that your DVD player is up-sampling to 96kHz in the digital realm and then performing the DAC (digital to analogue conversion) itself, and an analogue signal is what's going to your receiver. Pretty much any receiver ever made can handle analogue input. It doesn't matter what sample rate that signal was if the DVD player does the DAC step. All the receiver has to do is amplify the signal to drive your speakers. Now, if you have a PC hooked up using a S/PDIF coax cable and select 96kHz as the sampling rate, a 96kHz digital signal is being passed to your receiver and the job of converting that signal to analogue is left to the receiver. If your receiver can't handle 96kHz signals then it won't be able to play it. This is probably why your receiver can handle the signal from the DVD player and not from your computer.

    To answer your original question, yes it is possible to pass a 96kHz signal to your receiver over digital coax, but your receiver must support it. The difference in sound will be very subtle, if even perceptable. You're better off just passing the native sample rate of the media you're using. (i.e. 44.1 kHz for CD's and 48 kHz for DVD's)
     
  7. BrettisMckinney

    BrettisMckinney Second Unit

    Joined:
    Aug 25, 2002
    Messages:
    281
    Likes Received:
    0
    Trophy Points:
    0
    Perfect. You've answered my question perfectly. Thank you. I didnt think my receiver was 96kz capable so that would definately explain it. Thanks for taking the time to write that out for me..really appreciate it!
     

Share This Page