I notice that my levels are different when playing back on my iPOD. My dowloaded MP3's from my computer are louder than my cds that I have converted to iTunes which are softer. So when I try to shuffle all the songs I have to adjust my voulume at times. Is there a way to be able to have all at the same volume?

Scroll through the "settings" list on your ipod and choose sound check. It is supposed to regulate the volume so yo don't have this problem. On the computer side you could download mp3 gain and adjust the volume of all your mp3's then load them up on to your iPod.

I think that in order for Sound Check to work properly on the iPod, the option must be enabled both on the iPod and in iTunes.

Is it important to choose the same format to import music to the iPOD whether it is mp3's in my computer file or music from cd's? Does it matter as far as volume? What seems to be the best format I have read on the forums is use either AAC 192 or mp3 196..does that mean to keep this setting for whatever I import into the itunes software?

Quote: Originally posted by AndyH
I think that in order for Sound Check to work properly on the iPod, the option must be enabled both on the iPod and in iTunes.

This is right.. I don't think format makes a difference at all.. Go into iTunes prefs, and enable soundcheck, then do it on the iPod too. The above post is right, it won't work on the iPod unless it's turned on in itunes.

Quote: The above post is right, it won't work on the iPod unless it's turned on in itunes.

Yes, it does. The Sound Check info is added to your music files when you import them to iTunes. It is done automatically and there is no option to disable the application of these values to your files.
If you then want to use Soundcheck to level the volume of your files on the PC, just enable it in iTunes.
If you want to use it on your iPod, then enable it there.

All that the enable options do in iTunes or on the iPod is tell either iTunes or the iPod to start reading the Soundcheck info which has been applied during importing and level the volumes. One can work even if the other is switched off.

Quote: Originally posted by aquatika
Yes, it does. The Sound Check info is added to your music files when you import them to iTunes. It is done automatically and there is no option to disable the application of these values to your files.
If you then want to use Soundcheck to level the volume of your files on the PC, just enable it in iTunes.
If you want to use it on your iPod, then enable it there.

All that the enable options do in iTunes or on the iPod is tell either iTunes or the iPod to start reading the Soundcheck info which has been applied during importing and level the volumes. One can work even if the other is switched off.

In my experience, this is not correct. Apple even states:

Quote: When Sound Check is on, iTunes scans the songs in your library and computes characteristics of their playback volume. As new songs are added, iTunes computes this information in the background.

From this iTunes support document:
http://docs.info.apple.com/article.html?artnum=61655

As a test, I just turned on the option in iTunes on my work PC (with a small iTunes Library). iTunes now says "Determine Song Volume" and it's going through my entire library. So this leads me to believe that if you never turn the option on in iTunes, SoundCheck will not work properly on the iPod.

Yes, Andy is essentially correct, and that's been my experience as well. If you're watching you'll actually see iTunes go through the "Determine Song Volume" phase during import of new tracks as well, but only when Sound Check is on.

However, turning Sound Check OFF in iTunes does not clear this information from existing tracks. iTunes simply won't add the info to any new tracks that you import until you turn the option back on.

So this does mean that if you've ever had Sound Check on in iTunes, you will be able to use the Sound Check on your iPod, for those songs at least.

You can actually see this effect by opening up the files with an MP3 tag editor -- you'll see the info that Sound Check writes in the iTunes_Norm ID3 tag.

You could also get mp3Gain or use euPod, as it can run mp3Gain on every file on your iPod. euPod is a great little app and can be found in the Windows download section here on iPodlounge.

Quote: Yes, Andy is essentially correct, and that's been my experience as well. If you're watching you'll actually see iTunes go through the "Determine Song Volume" phase during import of new tracks as well, but only when Sound Check is on.

Well I just imported a CD track with the SoundCheck box unchecked (disabled) and the iTUNNORM tag was still added to the imported file.

AndyH, your quote actually could be construed as backing my claim up as well.

Quote: When Sound Check is on, iTunes scans the songs in your library and computes characteristics of their playback volume.

ie When enabled iTunes scans the songs already in your library looking for the Soundcheck info and applies it.

Quote: As new songs are added, iTunes computes this information in the background.

ie Automatically

Not getting into an argument or anything but I never have Soundcheck enabled on iTunes and the volume info still gets added to the files imported from a CD. I can see it in Foobar's tag editor.

Quote: Originally posted by aquatika
Well I just imported a CD track with the SoundCheck box unchecked (disabled) and the iTUNNORM tag was still added to the imported file.

....

Not getting into an argument or anything but I never have Soundcheck enabled on iTunes and the volume info still gets added to the files imported from a CD. I can see it in Foobar's tag editor.

Now that I look at it, it appears you're correct... Having only started using iTunes about a month ago, I've had a hard time keeping track of which CDs were imported with iTunes and which were imported with other applications. Once I checked the "Encoded With" tag, it became much more obvious.

One thing that is definitely true is that unless Sound Check is turned on, iTunes will not add iTunes_Norm information to files imported/added to the library from sources other than CD (ie, existing files dragged into the library). However, it appears that you're correct that this is added when importing from CD.

I just confirmed this with some testing. It's a fairly easy experiment, actually:

1. Turn OFF Sound Check.
2. Import a CD into iTunes
3. Import some new MP3 files (not previously checked by iTunes)
4. Turn ON Sound Check.

You will see that iTunes will process the MP3 files that you've added, but won't touch the ones that came from CD.

Quote: One thing that is definitely true is that unless Sound Check is turned on, iTunes will not add iTunes_Norm information to files imported/added to the library from sources other than CD (ie, existing files dragged into the library)

Agreed, although I just tried importing some non-iTunes MP3's into iTunes with the Soundcheck feature turned on. As you say it went through the little Determine Volume routine but at the end of it after I checked these imported files tags in Foobar the iTUNNORM fields still had not been added and turning Soundcheck on and off during the playback of these files made no difference to volume whatsoever.

Interesting, so far I've found that

1. CD's imported (MP3 or AAC) get the Soundcheck info attached
2. Non-CD imported MP3's get the "Determine volume" scan (if Soundcheck on) but then no Soundcheck info gets added.
3. Non-CD Imported MP3's if converted to AAC in iTunes get the Soundcheck info added (with Soundcheck on or off). Same vice-versa AAC to MP3.
4. Non-CD imported (iTunes) AAC's get the "Determine volume" scan (if Soundcheck on) and Soundcheck info is added if not already present.

Sorry to be anal but I had to satisfy my own curiosity, looks like we were all right and wrong at the same time. It seems to depend on what your using and how you use it.
Going by that though, it seems that if you use EAC and LAME (as I do) you cannot apply Soundcheck to the files (and thus use it on the iPod) unless you convert them to AAC in iTunes. Can anyone confirm this ??

Edit: Okay, as far as I can see unless iTunes is used to import a CD to either AAC or MP3 then Soundcheck info will not be applied.
It works when importing AAC files created on another PC by iTunes, (but they should have the Soundcheck info there already).
MP3's created by other software (like EAC and LAME), when imported to iTunes, do not get the Soundcheck info added.
This might explain a lot of the "Soundcheck is rubbish, it doesn't work on my iPod" threads that appear here.

See below for further info.

Another update.

After more playing around, it seems iTunes does add Soundcheck info to MP3's ripped with third party software (like EAC and LAME).
It just doesn't add the info to the tags like it does when importing a CD directly with iTunes. The info must be added to iTunes/ iPod database file instead.
This means that if you clear any scanned files from iTunes library (for whatever reason) they will have to be re-scanned when you re-import them. Much like Playcounts and Ratings can be lost.

For this to work, import any MP3's ripped independently of iTunes and then enable the Soundcheck feature. Edit/ Preferences/ Audio and select Soundcheck (this can be done before or after importing as iTunes will scan any new files as soon as Soundcheck is enabled).
This will scan your imported MP3 files (as AndyH and jhollington mentioned earlier) and apply the volume adjustment.

Once this is done, it can be enabled on both the iPod and in iTunes whenever it is required. After the initial scan, it is not necessary to leave either the iPod or iTunes with Soundcheck enabled. It can be used as and when.

Just remember to enable it again in iTunes if importing new MP3's so that they can be scanned also.

OK... I'm new to the iPod and iTunes...

I've been ripping MP3 from my CD collection for a long while though and still happen to be using LAME. My database of MP3s was added to iTunes and then synced to my new iPod just this week.

In preparing for a party (happy birthday to me!), I created a playlist and noticed the huge volume shifts from CD to CD as the playlist was shuffling. Of course, I decided to play with "Sound Check". I went into iTunes, enabled it, and watched it scan all of my precious MP3s. I also noted that the time/date stamps on the files we're all updated.

Hmmm... you keep mentioning some sort of ID3 tag (ITUNENORM, I think). Is this all iTunes has done? Just added this iPod/iTunes specific parameter to each of the scanned MP3s?

I guess what I'm asking is... Is the original MP3 data untouched? Will this file appear exactly the same to any player other than iTunes/iPod with Sound Check enabled?

Does anybody care to give me some technical details about how "Sound Check" is supposed to work (i.e. Mechanism/Results)?

Cheers, Mike

In my experience,

If you rip with external software (like EAC and LAME) and then import the music files into iTunes and scan them for Soundcheck, no tag gets added to your files.
That only happens if the CD's were ripped with iTunes itself. In your case the Soundcheck info is added to the iTunes/ iPod database file.

Soundcheck does not physically alter your original files in any way and if you were to "Clear" all your scanned music from iTunes the Soundcheck info would be gone and you would have to re-scan them if you decided to re-import them in the future.

The files, if used with another player, will be quite normal.

I don't know much about the tech side of it, but it seems to be an attempt by Apple to apply the replaygain standard here although it is not as good as MP3Gain or Foobar's replaygain scanner and it's results can still cause varied volumes in some instances.