Dismiss Notice
Attention AVForums app / Tapatalk users
Sadly GDPR means that, from 25th, we can no longer offer access to AVForums via the branded app or Tapatalk.
Click here for more information.

"Hi-Bit" on Pioneer AX5i and AX5ai

Discussion in 'AV Receivers & Amplifiers' started by MJeeves, Dec 23, 2004.

Tags:
  1. MJeeves

    MJeeves
    Well-known Member

    Joined:
    Feb 15, 2001
    Messages:
    4,054
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Crayford
    Ratings:
    +224
    Hi,

    I have a Pioneer AX5Ai and wondered what the "HI-BIT" function is for. It says that it increases dynamic range for SACD, DVD-Audio and DVD-Video discs, yet the default position is "OFF". Can anyone tell me in a bit more detail what it does and should I be using it for optimum sound quality?

    Thanks, Martin.
     
  2. Kier

    Kier
    Active Member

    Joined:
    Nov 21, 2004
    Messages:
    133
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Reading, UK
    Ratings:
    +3
    Simplistically speaking, the hi-bit function does some post-processing on the sound source in order to make it sound a bit better.

    Of course it can't create detail that isn't present in the original recording, but what it can do is smooth off some of the harsh edges present in lower bitrate sources.

    As a simple illustration, let's take the example of CD audio and DVD audio.

    CD audio samples at 44KHz, which means that it samples the audio 44,000 times every second. On the other hand, DVD audio can sample at a much higher 92KHz.

    Now let's think about representing a sound waveform digitally. The original waveform (before recording) would have been a perfect curve, but to represent that curve digitally, it has to be broken into 'steps'. With the lower bitrate CD audio, these steps are relatively large, resulting in relatively large jumps between audio samples. DVD audio on the other hand has a higher sampling frequency, so the steps are smaller, resulting in a more accurate representation of the original waveform.

    Put simply, the hi-bit function attempts to smooth off the steps using interpolation, with the result that the sound (usually) more closely represents the original waveform.

    For the most part it results in a better sound.
     
  3. MJeeves

    MJeeves
    Well-known Member

    Joined:
    Feb 15, 2001
    Messages:
    4,054
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Crayford
    Ratings:
    +224
    Thanks. So you suggest keeping "HI-BIT" on for movie soundtracks and SACD's then?

    Thanks again. M. :thumbsup:
     
  4. Phill1978

    Phill1978
    Active Member

    Joined:
    Oct 15, 2004
    Messages:
    2,045
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    48
    Ratings:
    +84
    wouldnt have thought SACD`s would benefit ??
     
  5. MJeeves

    MJeeves
    Well-known Member

    Joined:
    Feb 15, 2001
    Messages:
    4,054
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Crayford
    Ratings:
    +224
    Thanks. So you suggest keeping "HI-BIT" ON for movie soundtracks then?

    Thanks again. M.
    __________________
    M.J.
     
  6. Kier

    Kier
    Active Member

    Joined:
    Nov 21, 2004
    Messages:
    133
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Reading, UK
    Ratings:
    +3
    Hi-Bit on for everything except DVD-Audio, SACD and DTS 96/24 :) (for which the amp will automatically switch it off anyway)
     
  7. Kier

    Kier
    Active Member

    Joined:
    Nov 21, 2004
    Messages:
    133
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Reading, UK
    Ratings:
    +3
    Oh, and turn on MIDNIGHT mode too - makes a big difference to the perceived richness of the sound below -20dB volume (at which point it switches off automatically anyway)
     
  8. MJeeves

    MJeeves
    Well-known Member

    Joined:
    Feb 15, 2001
    Messages:
    4,054
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Crayford
    Ratings:
    +224
    Huh???? :confused:
     
  9. Kier

    Kier
    Active Member

    Joined:
    Nov 21, 2004
    Messages:
    133
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Reading, UK
    Ratings:
    +3
    Midnight mode is designed to compensate for low volume levels, which (on a THX amp) is anything below ear-shattering.

    Try listening to something at -30dB with and without midnight mode... you'll soon see what I mean.
     
  10. MJeeves

    MJeeves
    Well-known Member

    Joined:
    Feb 15, 2001
    Messages:
    4,054
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Crayford
    Ratings:
    +224
    I normally have mine at about -15db but with MIDNIGHT MODE OFF. Will MIDNIGHT MODE ON at -15db be too loud? What settings do you have on your amp?

    Thanks for all your help :thumbsup:
     
  11. Kier

    Kier
    Active Member

    Joined:
    Nov 21, 2004
    Messages:
    133
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Reading, UK
    Ratings:
    +3
    Midnight mode only functions below -20dB - above that it has no effect upon the sound. I have it turned on all the time because I use my amp for regular TV and background music as well as in-your-face movies etc.
     

Share This Page

Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice