Sound Check issues
Hi, I'm a new member, greetings to all...
I love my 3G iPod 30GB. I use it with firmware version 2.0.1, Mac iTunes 4.0.1, OS X 10.2.8.
My problem is Sound Check. It generally works OK to even out songs' volumes, but some songs are quite noticeably softer than they should be, and they come up to proper volume only when I turn Sound Check off (!) on the iPod.
I can't find much information on how Sound Check works. I know it analyzes song files and stores something in the iTunes music database to change their playback level as needed. This is done, I gather, independently of the volume settings made in iTunes Info.
Other than that, I'm in the dark. I need more information before even trying to guess why Sound Check messes up on certain songs. Exactly what is Sound Check doing, and why would it not work all the time?
[880 byte] By [
epstewart] at [2007-11-9 14:42:09]
# 1 Re: Sound Check issues
there is an answer to this if you use a mac (don't know if it works on a pc) over at the apple forums a nice bloke has written a script for itunes that solved all my volume problems.
my music collection is pretty varied and includes a lot of old cds, these cds are much quieter than new cds, however when i adjusted the volume of the mp3 in itunes so that they were all the same, i found that the ipod exagerrated any volume changes that i'd made (either up or down) by quite a bit (by a factor of 8 or something apparantly)
this nice bloke i mentioned earlier has written a script to sort this. all you do is adjust the mp3 volume in itunes so that they all have the same sound level, copy them over to the ipod then run the script. The script adjusts any changes you've made to 16% of the change and puts the word 'done' in the comments box so that it doesn't alter it again the next time you run the script. The result is songs all the same volume.
if you would like the script head over to
http://discussions.info.apple.com/W...9hXU.2@.f02116d
and ask for it. I can't give it to you as the creator wants to keep it on the apple forum so that apple can see how many people want the script and hopefully take notice and fix the bug.
# 2 Re: Sound Check issues
Dave,
Actually, I don't think the script you mention solves my problem, which is with Sound Check's automatic level adjustment, not with how the iPod handles manually adjusted volume levels.
If I wanted to go through my collection song by song and change the volume of each song by hand, I could. But isn't that exactly what Sound Check is supposed to make unnecessary?
From prowling around in search of answers relating to the Sound Check problem, I was already aware of the separate problem in which the iPod exaggerates manual music volume adjustments by (someone somewhere said) a factor of six times the actual adjustment.
Of course, it may be that the same exaggeration applies to Sound Check adjustments, too. It depends on exactly how Sound Check does its thing. I do know that on some of my tracks Sound Check seems to lower the volume a huge and inappropriate amount, such that when I turn off Sound Check on the iPod while the song is playing, the volume for that song jumps back up to a reasonable level. It may also be that iPod, in honoring Sound Check, boosts the volume of certain other song files way too much, but I haven't really checked that aspect of the situation as thoroughly.
Can't somebody post a reply going into a bit of technical detail on the way Sound Check actually works? Then maybe a solution to the specific problem of incorrect Sound Check-controlled volumes would emerge.
I know from my investigations in Apple's own forums and elsewhere that other people have reported similar problems with Sound Check, so I'm not the only one that has them. But the only solutions anyone has suggested have all involved abandoning Sound Check and going to one or another alternative approach, each of which has severe drawbacks, in my humble opinion.
For example, one thing I have tried is Manfred Lippert's iVolume plugin to iTunes. It's quite effective at equalizing volumes -- except that it won't equalize volumes on protected AAC music files downloaded from the iTunes Music Store! To me, that ruins the whole thing!
Mani, as he is known, has told me in e-mail that he is "working on a workaround that looks promising. So hopefully iVolume will support protected AAC songs in some future version." I have my fingers crossed -- but wouldn't it be nice if Apple just corrected the specific Sound Check problem and/or whatever other problems keep Sound Check from really working in iTunes and on iPods?
We definitely need something that will automatically and properly equalize volumes on all types of tracks iTunes and iPod can play.
# 3 Re: Sound Check issues
i gave up on the whole sound check thing and just use the script. i used a 3rd part programme to adjust the mp3 volumes of the tracks i had already ripped and now i adjust by hand each album/song added since. then copy to the ipod and run the script. had no problems since.
# 4 Re: Sound Check issues
Dave,
What was the third-party program you used to adjust the mp3 files' volumes?
You know, the more I think about this, the more I wonder if the iPod's problem of exaggerating song file volume adjustments by a 6X factor or whatever isn't causing the perceived Sound Check problem. Maybe this is what happens: Say a song is a smidgen too high in volume, so Sound Check in iTunes internally "sets" its playback volume just a little lower to compensate. Then the iPod magnifies that minor downward tweak into a major drop in volume by multiplying it by six. Result: instead of the song playing back at the correct volume, the volume comes out way too low on the iPod. The same thing would apply in the opposite direction to make songs that are supposed to have a small upward adjustment way too loud instead on the iPod.
So maybe the 6X multiplier on iPod works the same way with Sound Check adjustments as with manual ones -- except that you can't use a script to cut the Sound Check adjustments to a factor of 16%, the way you can with a manual adjustment.
At any rate, why doesn't Apple just fix the iPod bug? It isn't as if no one has reported it.
# 5 Re: Sound Check issues
i used mp3 rage which takes a long time (had to let it run all night). you select an mp3 for the target volume then it goes through each one in the library and adjusts it accordingly to the target track. you can get it from macupdate.com
# 6 Re: Sound Check issues
Dave,
Yes, MP3 Rage works pretty well to normalize volumes on song files. I've tried it. But, again, it doesn't work with AAC files downloaded from iTunes Music Store. Also, as you say, it takes forever to go through a whole music library. And even then, you still have to use the script you mentioned, plus manually adjust the volumes on any new songs in the library (or use MP3 Rage again).
So I don't consider that the answer to the problem. At best, it's a cumbersome workaround. The more I think about it, the more I believe a fix by Apple to the problem of the iPod magnifying song files' volume adjustments is the sine qua non here.
# 7 Re: Sound Check issues
I'm the original poster in this thread. I think I've managed to confirm experimentally that the main problem with Sound Check when used with an iPod is really the known problem of having the iPod magnify volume level adjustments by a factor of 6 times the "proper" adjustment. That is, this bug in the iPod affects manually made volume changes in song files and also volume changes made by Sound Check.
I took a song file that plays back way, way too loud on the iPod when Sound Check is on and compared its volume to a couple of "normal" files on the iPod and also in iTunes on my Mac. On the Mac, with Sound Check on all the songs played at roughly the same volume. On the iPod with Sound Check on, as I say, this one song played back much, much louder than the other two.
When I turned Sound Check off on the Mac, the song in question played back at somewhat lower volume than the other two, meaning that Sound Check was trying to turn it up a smidgen. The result was fine in iTunes, but the iPod turned it up inordinately much.
So I'd say Sound Check may not be perfect, but it works reasonably well except when the bug in the iPod exaggerates its effect.
But there's something I don't get at all: when I turn Sound Check off on the iPod, the song in question does not have a volume level lower than the other two songs, as it does in iTunes on the Mac with Sound Check off! It's volume is "correct" with respect to the other two songs. Go figure.
UPDATE:
I'm revising this message because I've discovered an X-factor I didn't know about: that song file I mentioned, the one that plays back way, way too loud on the iPod when Sound Check is on, had its volume adjustment set higher than the "middle" or "none" setting in iTunes Get Info:Options. It's from an album-on-cassette that I digitized and compressed into MP3 format outside of iTunes. Each song on the album has a different volume adjustment in iTunes, courtesy (I think) of MP3 Rage from back when I was using it.
(Specifically, it's Billy Joel's "52nd Street" from the classic album of the same name.)
So I manually set the volume adjustment on the song back to "none" in iTunes. I turned Sound Check off in iTunes and the song played back too soft. I turned Sound Check back on and it played back at the right volume. I updated the iPod with my changes and played the song back with S.C. off (too soft) and with S.C. on (just right).
So what I said earlier about S.C. in the iPod exaggerating volume adjustments made by S.C. in iTunes is probably wrong. I'm going to go through my iTunes library and remove manual volume adjustments and see what happens.
SECOND UPDATE:
I removed all manual volume adjustments in iTunes and wound up with (enabling Sound Check both in iTunes and on the iPod) a music library whose volumes are pretty darn consistent from one song to another, both in iTunes and on the iPod.
The only exception I've found so far is an old Frank Sinatra song, "Nancy (With the Laughing Face)," that seems to play back too loud in both situations, so I lowered its volume manually in iTunes. It now plays back with the "right" volume both in iTunes and on the iPod. (Technically, this song probably plays back with the same volume as the other songs, but it sounds too loud because Sinatra's voice is too far "forward" in the mix by today's standards, and there is very little bass or dynamic range.)
I must admit that I'm surprised that the manual adjustment that "works" for this song in iTunes also works on the iPod. That would seem to contradict the assumption that my iPod's current software version (2.1) magnifies manual volume adjustments made in iTunes by a gross factor of 6X.
While I was experimenting, I noticed the interesting fact that iTunes, when Sound Check is enabled, shows the number of ? decibels of volume adjustment Sound Check is making for each music file in the Get Info: Summary panel in the Volume: item. This item does not appear when Sound Check is disabled, however. It will re-appear if Sound Check is re-enabled. (You have to close the Get Info window in order to change the status of Sound Check in iTunes Preferences, however.)
# 8 Re: Sound Check issues
Originally posted by dave_b9000
i used mp3 rage which takes a long time (had to let it run all night). you select an mp3 for the target volume then it goes through each one in the library and adjusts it accordingly to the target track. you can get it from macupdate.com
yes, i agree a fix by apple is the answer ( i have filled in the feedback form requesting such a fix) but in the meantime it's what i need to do in order to listen to my music without rushing to the remote to change the volume every song.
# 9 Re: Sound Check issues
might be of interest
http://www.macupdate.com/info.php/id/12687
it includes the option to adjust the volume for the ipod (meaning you wouldn't need to use the script however it would change the volume of the itunes songs before transfer rather than the ipod ones after transfer)
# 10 Re: Sound Check issues
Dave,
iVolume 1.2 by Mani Lippert is a good piece of software -- but unfortunately it does not yet work with protected AAC (Apple Audio Codec) files downloaded from the iTunes Music Store. It just works with MP3s and unprotected AAC files like you might create yourself in iTunes.
Eric
