iTunes 3 Sound Check = messed up MP3s

zozo
Posted:
in Mac Software edited January 2014
Havent seen this elsewhere but I aside from the EXTREMELY annoying 'feature' of reorganizing your entire library, I found that the sound check 'feature' messed up a LOT of my MP3s. Some high and low bass's got fubar and sounded distorted after normalizing.



Luckily I had merely copied my MP3s from my External HD onto my iBook so I could just recopy them and not have iTunes "Sound Check".

Comments

  • Reply 1 of 13
    Turning off the Sound Check doesn't allow the MP3s to play normally again?
  • Reply 2 of 13
    zozo Posts: 3,115member
    nope. I was playing a track from a soundtrack that had some pretty low bass that had been "Sound Checked" and it sounded horrible. I took the backed-up the track from my external HD to my desktop and then JUST played that. No more messed up audio.
  • Reply 3 of 13
    [quote]Originally posted by ZO:

    <strong>Havent seen this elsewhere but I aside from the EXTREMELY annoying 'feature' of reorganizing your entire library, I found that the sound check 'feature' messed up a LOT of my MP3s. Some high and low bass's got fubar and sounded distorted after normalizing.



    Luckily I had merely copied my MP3s from my External HD onto my iBook so I could just recopy them and not have iTunes "Sound Check".</strong><hr></blockquote>



    oh no! i just did that! aaaaaahhhhhhhh shiiiiiiiiiiiiiit. im screwed. so should i not take off the sound check?
  • Reply 4 of 13
    alcimedesalcimedes Posts: 5,486member
    there are two sound checks though aren't there?



    there's a sound check you can run from you iTunes app, as well as a sound check option on your actual iPod.



    what happens if you have sound check turned on on the iPod, but not in iTunes?



    -alcimedes
  • Reply 5 of 13
    ensoniqensoniq Posts: 128member
    Just for clarification...Apple's Sound Check feature does NOT modify your original MP3 files in ANY WAY.



    I repeat:



    The MP3 data does not get changed.



    The treble and bass are not modified.



    Nothing permanent is done to the files.




    All Sound Check does is scan your files to determine an "average" volume level. It does this so that as you listen, you don't need to turn up the volume to almost max for a very soft MP3 recording, only to have the next song blow out your speakers/headphones.



    The Sound Check settings are stored in the external iTunes Library database file. Therefore, it IS true that even if you turn off Sound Check to prevent it from calculating volume on new songs, the database will still in be in place for songs already calculated.



    The way around this for those who don't like the Sound Check adjustments is to turn off the feature in preferences, delete your library, and then re-import the songs. (You don't have to re-rip them, you just re-add them to the library.)



    Hopefully this information will help some other people in the future who decide that Sound Check isn't right for them.



    -- Ensoniq
  • Reply 6 of 13
    Actually, Ensoniq, you are only half right.



    If the MP3 files in question have ID3 tags earlier than version 2.4, the sound check data is stored in iTunes' library file. However, if the MP3 file has ID3 tags of version 2.4, the Ratings and Sound Check adjustments get stored in the file itself because of the extra fields in the 2.4 tag spec.



    I just tested this myself with two MP3s. The one with ID3 v2.4 was modified by iTunes.



    Hopefully the next version of MP3Rage will allow us to modify or remove those tags. Meanwhile, you should be able to remove these tags in iTunes by selecting the MP3s and choosing "Convert ID3 tags" from the Advanced menu and then change them to 2.3.



    [ 08-19-2002: Message edited by: Brad ]</p>
  • Reply 7 of 13
    I have yet to test this theory but since

    A) Sound check doesn't affect the original mp3 except to (perhaps) store the average volume in an ID3 tag and

    B) the sound processing takes place when the song is played (iPod didn't soundcheck till after a firmware update)



    I presume that whatever happened here is not related to soundcheck and there is no need to rerip your CD's or fiddle with the ID3 tags. Just unchecking sound check returns my AIFFs to their original volume. Why would it do anything else?
  • Reply 8 of 13
    zozo Posts: 3,115member
    all i know is that after I let iTunes sound check a few gigs of MP3s, some with a lot of bass or rhythm got crackled and played like $hit.



    I even quit iTunes and restarted the song, same thing. I then, again to say it, recopied the same 'pre sound checked' mp3 to my HD and played it without having it analyzed or anything and played it in iTunes 3 (after having unchecked "Sound Check" in prefs) and the song played perfectly. This happened with a few other MP3s.



    Nothing else could have happened to the files seeing that I had had Jaguar installed only since about 12 hours.



    Nonetheless, MOST songs were fine... no real deifference actually. Kinda made me feel the Sound Check was totally useless.
  • Reply 9 of 13
    ZO:



    Have you tried what I suggested? About converting the ID3 tags to a earlier version like 2.3?
  • Reply 10 of 13
    eugeneeugene Posts: 8,254member
    iTunes claims the encoded mp3s it makes use ID3 v2.2 tags for me, heh.
  • Reply 11 of 13
    zozo Posts: 3,115member
    Starfleet... ahem... I mean Brad



    I erased all the old (Sound Checked) MP3s and recopied them from my external drive, so I dont have the old ones anymore... sorry.



    ZO
  • Reply 12 of 13
    Just out of curiousity, have you listened to these 'screwed' MP3s on any system other than your own? Copy them to another machine or a portable MP3 player and see if they are still affected.



    For what it's worth, Sound Check has had no ill effect on any of my MP3s (so far).



    And yes, in order for an iPod to take advantage of the Sound Check feature they have to have the info imbedded in the ID3 tag. I'm considering re-ripping all my CDs using iTunes3, 'cause Sound Check is definately something you'd want on an iPod.
  • Reply 13 of 13
    blizaineblizaine Posts: 239member
    guys,



    I got worried for a second because I turned on Sound Check a few days ago... Well, if you play an mp3 and while it is playing check or uncheck "Sound Check" and hit "Ok" you will hear the volume change.



    no need to go editing ID3 tags....
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