Use dithering when editing commercial CDs?

Discussion in 'Digital Audio' started by Sir Cecil, Mar 7, 2009.

  1. Sir Cecil macrumors 6502a

    Mar 31, 2008
    When editing standard red book music CDs via my MBP and an editing program like Peak or Jam 6 – adding crossfades, editing out sections and possibly adjusting the level of some tracks so a compilation from various CDs has consistent sound levels – should dither be added?

    I have read conflicting info. I have Peak and that offers a dozen or more dithering options, confusing me completely. The manual is not helpful on this.

    As I understand it, dithering is to be applied when say, coming down from 24bit to 16 bit. So I assume on a 16 bit CD, dithering has already been applied. But then I read that dithering should be applied to any file after crossfading/editing it. Then... I read that dithering an already-dithered recording will result in loss of sound quality. Erk! I'm lost on this.

    Any answers appreciated.
  2. zimv20 macrumors 601


    Jul 18, 2002
    it's probably the case that the software is dithering automatically when you're doing cross-fades.

    imho, if you're not changing bit-depth, i wouldn't bother adding a dither stage yourself.
  3. Sir Cecil thread starter macrumors 6502a

    Mar 31, 2008
    Jam 6 has a checkbox that applies dither, if selected. Their "Help" section says it helps prevent distortion during crossfades/level changes. But I haven't heard any difference in CDRs made with or without the dither box checked. Nevertheless, I want to be sure I'm doing the right thing to ensure optimal results.

    Peak just gives a load of dither options that need to be applied manually.

    Still unsure.
  4. zosoaudo007 macrumors member

    Dec 27, 2007
    You don't need to dither when crossfading and all that stuff.

    Dithering is the absolute last step in bouncing your audio out.

    Dithering is only needed when you are going from a higher bit rate to a lower bit rate. So to save a 24 bit file as 16 bit, you should dither.

    Izotope has a great guide on this topic. They give you a pdf, some audio files, and all sorts of analogies and diagrams that help.

    The audio files are very effective. The levels are incredibly low so you can hear how the dithering has affected the audio. I recommend closing all your apps except your file player and using a nice pair of headphones in a quiet area.

    Download the dithering guide, and the dithering sound files.
  5. Sir Cecil thread starter macrumors 6502a

    Mar 31, 2008

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