Current surround formats on receivers/preamps

Discussion in 'Audio Visual' started by Tony, Sep 18, 2002.

  1. cerberos

    cerberos Member

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    its just that nyquist has to assume a few things, like what the wave shape is.

    its one of those rules that is very useful to a professional who knows the field, but it can be badly mis used by laymen
     
  2. critter

    critter Member

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    from DSP first a multimedia approach

    "A continuous-time signal x(t) with frequencies no higher that fmax can be reconstructed exacltly from its samples x[n]=x(nTs), if the samples are take at a rate fs=1/Ts that is greater that 2fmax."

    this is assuming that the input is composed of sinusoidal singals limited to the set of frequencies in the range 0<f<fmax. and since any waveform can be made up from sinusoids (using fourier series) i don't see any problem.
     
  3. cerberos

    cerberos Member

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    other than the problem of needing infinite frequency to get anything other than a sin wave out of sin waves, so then the required frequency of sampling is infinite, and not all music is made purely of sin waves, look at some of the distortion pedals in use.
     
  4. critter

    critter Member

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  5. cerberos

    cerberos Member

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    no you can't its bloody useful, you just have to know its limitations
     
  6. CailYoung

    CailYoung Member

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    Surely SAE would have told you that the 192kHz figure means the sampling rate of the digital audio, not the upper limit of the frequency response?! DVD Audio formats usually have around 192,000 samples per second which they shorten to 'Hz'. CDs have 44,100 samples per second, as a comparison. So yes, DVDs will be closer to the original sound wave as both the sampling rate is higher and the values are quantized less (20-bit means there is more accuracy to each sample than the 16-bit of most CDs).

    Cail
     
  7. critter

    critter Member

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    Its more than bloody usefull

    quote:"To close this chapter, consider that the FFT is to Digital Signal Processing what the transistor is to electronics. It is a foundation of the technology; everyone in the field knows its characteristics and how to use it. However, only a small number of specialists really understand the details of the internal workings."


    Do a google search and you will find this free book on the net:
    The scientist and Engineer's Guide to Digital Signal Processing.
     
  8. Azzjw

    Azzjw Member

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    Surround Formats!

    Ok, this thread is about surround formats so here goes.

    MPEG 5.1

    Dolby Digital
    Dolby Digital EX
    Dolby Prologic
    Dolby Prologic 2
    DVD Audio

    DTS
    DTS ES Discreet
    DTS ES matrix
    DTS Neo
    DTS Audio

    SRS Circle Surround
    SRS Circle Surround 2

    Sony Dynamic Digital Sound
     
    Last edited: Feb 6, 2003
  9. kanepham

    kanepham Member

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    I think I fulfil that condition :(, it really is annoying, I am extremely sensitive to especially high pitched sounds.
     
  10. cerberos

    cerberos Member

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    <grumble gbrumble grumble?
    bloody dice with not 17kHz+
     
  11. Chronos

    Chronos Member

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    I'd like to add that unlike Dolby Digital formats, DTS is uncompressed. i.e. lossless.

    :)
     
  12. Audiobuzz

    Audiobuzz Member

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    No DTS is still a compressed format as the bit rate is much less than the raw sample bit rate, and although it is closer to lossless than DD, it is still technically lossy.

    Bed-time reading:

    General surround formats info

    DTS white paper

    AB
     
    Last edited: Jul 24, 2003
  13. cerberos

    cerberos Member

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    btw i had a lecturer claim that 5.1 audio is a 7 dimension signal, some people are so stupid
     
  14. sefu88

    sefu88 Member

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    what they need is a sound format called DTS ORIGINAL NO BULLSHIT COMPRESSION OR MODIFICATIONS MADE. Thus sound recored exactly the same as the studio(ovoiusly depending on the equipment in use will change the sound in your living room).

    Also get that blueray shit already :p so we can have those phat music files on a DVD. mmmm 10gig allocated just for sound.
     
  15. Audiobuzz

    Audiobuzz Member

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    It's called PCM :p
     
  16. cerberos

    cerberos Member

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    god damn that'd sound bloody average. i mean how much time is the average joe exspected to take in mixing the song so it sounds right?
     
  17. sefu88

    sefu88 Member

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    Im not sure what you mean.

    But what i was trying to say have a sound format with no compression. a non-lossy format.

    Or does compression have to exisist for a sound to be digitalised and what i want not possible??
     
  18. CailYoung

    CailYoung Member

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    Compression is not necessary, audiophiles who have problems with digital audio in general are complaining about 'quantization', in which the audio waveform is matched as closely as possible to a list of possible values - they say this introduces changes that are unacceptable.

    Uncompressed multi-channel audio at high resolution (i.e. 24/96 or even higher) takes up gobs of data. Lossless compression is an option - ZIP, SIT, RAR, etc are all lossless compression, which means that every single bit that goes in comes out again. However the difficulty comes in being able to decompress lossless data fast enough for realtime audio playback. FLAC manages, I believe, it just has to be implemented in hardware.

    Cail
     
  19. Shintaro

    Shintaro Member

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    Don't we already have a lossless compression method in the form of MLP (DVD-A) ????
     
    Last edited: Nov 15, 2003
  20. archie

    archie Member

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    bit of a n00b question and from my little understanding it can't really be compared but i'll ask anyway...

    which is better?

    LPCM 2.0 1536Kbps
    or
    DD 5.1 448Kbps

    to me on my mediocre 4.1 pc setup the LPCM sounds richer and fuller.

    cheers
     

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