Is 128kbps enough in iTunes?

Discussion in 'Mac Apps and Mac App Store' started by daneoni, Sep 15, 2006.

  1. daneoni macrumors G4


    Mar 24, 2006
    I was just talking to a friend who suggest i encode my MP3 tracks with 198kbps instead of 128. I thought this was good when dealing with MP3 formats but for AAC 128 is enough right? or is 192 better in any scenario. What are you guys using?. Also is the standard itunes encoder sufficive or should i use LAME?
  2. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    It all depends on your ears, and the song. Most of my songs sound fine to me at 128, although there are a few which I believe sound awful. I always rip at 128 to begin with, then re-rip any tracks I'm not happy with.
  3. Cordless_Drill macrumors regular


    Jul 6, 2004
    Montgomery, Ala., USA
    I prefer AAC at 128. If you have to encode in mp3, at least to me, I think 192 is a better option. It's a larger file but I think the sound quality is worth the extra space.
  4. jive macrumors 6502a

    Apr 14, 2006
    I use AAC at 320Kbps. I can tell the difference when I play a song that's of a lesser quality...

    192 is good though. Go for that.
  5. j26 macrumors 65832


    Mar 30, 2005
    My entire collection is 128 AAC and it's fine. I haven't encountered a song yet that I've thought needs to be re-ripped.
  6. daneoni thread starter macrumors G4


    Mar 24, 2006
    Thanx for all the replies, decided to re-encode me entire library with 192kbps and VBR to see the difference...if any. I hope the almighty G4 can take it :eek: . Maybe i should have waited till i jumped on the intel wagon before doing this oh well..
  7. LethalWolfe macrumors G3


    Jan 11, 2002
    Los Angeles
    If you've already encoded your songs at a bit rate that you find acceptable what does it matter what your friend says? You're the one that's going to be listening to the tracks, not him.

    Unless you think ripping at a higher bit rate sounds better and it's enough of an improvement to warrant the time/effort to re-rip everything then I don't see the point.

  8. daneoni thread starter macrumors G4


    Mar 24, 2006
    Is it really acceptable, its more like i got used to what i have now. I still yearn for CD quality music as much as possible (Lossless/AIFF is impractical). I sampled the tracks on his player and they sounded pretty amazing. I'm hoping i can get close to that as much as possible.
  9. bankshot macrumors 65816


    Jan 23, 2003
    Southern California
    I really encourage you to do a double-blind listening test on a variety of songs that you know well. A lot of people fool themselves into thinking they can hear a difference in quality, simply because they know a file was encoded with a particular bitrate. It's a psychological thing. If you know a file was compressed, your brain is more likely to tell you it heard more artifacts even when it didn't.

    A good double-blind test might surprise you -- I know it surprised me when I did it. To set this up properly, follow these steps:

    • Rip a song to a lossless format like AIFF.
    • Convert it to AAC/MP3/whatever using the bitrate you want to test.
    • Convert the lossy file (AAC/MP3) back to AIFF. Now you should have two AIFF files: one that's straight from the original CD, and one that has been converted to AAC/MP3 and back.
    • Have a friend rename the two AIFF files to "A" and "B". The choice of which file becomes "A" and which becomes "B" should be completely random. Alternatively, if you're technically inclined, you could write a little script to do this for you (just make sure it saves what it did somewhere that you can check later).
    • Have the friend/script randomly pick one of the two files ("A" or "B") and make a copy of it called "C".
    • Now listen to all three files carefully and write down whether you think each one was the original or the converted version. An easy way to do this if you have QuickTime Pro is to set preferences to play audio from only the active window, and use the "Play all movies" menu choice to start them all at once. Then click back and forth on the different player windows to move back and forth between A, B, and C.
    • Check to see how you did, and keep a tally of how many were right and how many were wrong.
    • Repeat the process several more times. Try it multiple times with the same song, and try it with other songs too. Did you do better than random guessing (50% right)?
    • If you did better than random guessing, try the whole thing at a higher bitrate.

    This can be very time consuming, but I found it very enlightening and worthwhile. I ultimately settled on 160kbps AAC for my library. I thought I'd go higher, but oftentimes when I thought I heard a compression artifact, it turned out that the same artifact was present in the original source.

    Ultimately it's a personal decision, but how can you know you've made the right decision unless you've ruled out external influences (namely, knowing the compression level of a file beforehand and therefore tainting your perception of it)?
  10. daneoni thread starter macrumors G4


    Mar 24, 2006
  11. steelfist macrumors 6502a

    Aug 10, 2005
    it's annoying that people don't pick the middle ground: 160 kbps. it's very good for most people.
  12. spicyapple macrumors 68000


    Jul 20, 2006
    AAC is more efficient than MP3, so I would say 128Kbps AAC is roughly 192Kbps - 256Kbps of MP3. iTunes AAC encoder is very high quality, one of the best. :)
  13. daneoni thread starter macrumors G4


    Mar 24, 2006
    Carried out the expt suggested by bank above and the difference was very marginal but existed. So i compromised and went with 160kbps instead its ok and doesnt take up extra space than necessary

Share This Page