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Topic: iPod Normalization |
b0b
From:
Cloverdale, CA, USA
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Posted 22 Jun 2008 8:22 am |
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I now have a wide variety of music on my iPod (over 3500 songs). The volume levels vary quite a bit from classical to jazz to rock to country and then to (loudest) music mixed for radio. I know that I can change the volume level on individual songs in iTunes, but that's real trial-and-error, one-by-one stuff.
Is there any way to tell the iPod to normalize volume levels? I mean, I love the Beatles, but after a Sibelius violin concerto they sound really loud.
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-πππ- (admin) - Robert P. Lee - Recordings - Breathe - D6th - Video |
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Mitch Drumm
From:
Frostbite Falls, hard by Veronica Lake
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Posted 22 Jun 2008 9:50 am
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Bob:
I use mp3gain, available as a free download.
Get it here:
http://mp3gain.sourceforge.net/
It works ONLY with mp3s.
I have been using it for several years with no complaints at all. I play back directly from Itunes on my PC, but I don't see why it wouldn't work for your purposes as well.
As I recall, it doesn't modify the recording per se, but introduces something in the file that adjusts the playback.
Track gain modifies all songs so they sound equally loud, disregarding the dynamics of an album.
Album gain modifies all songs to bring them nearer to set dB, keeping the dynamics of an album.
I use "track gain" rather than "album gain" because I listen to random tracks one after another--a Presley song followed by an Emmons song. If you generally listen to one album followed by another album, you might want to fiddle with "album gain". It may not make much or any difference which you use.
You start it up, navigate to a given folder, and "analyze" the songs in the folder, which takes roughly 5 seconds per song. Then you hit the "gain" button, and the results of the analysis are transferred to each song individually. That takes a split second per song. Very slick.
The default target "normal volume" of 89.0 db works fine for me. I use defaults throughout the program.
Here is a blurb I saved a few years ago on the subject in general, comparing mp3gain to other programs:
There seems to be too little information being put forward here. How about a recap and summary to clear things up?
ReplayGain is basically a method for determining the perceived volume of a song. That's really all it is, in and of itself, it doesn't change anything. You scan the song data, do some math, and get a number.
To make songs sound the same, you have to make all your songs have the same number. To do this, you apply gain. So if a song has a RG number of 83 dB and you want to make everything sound at 89 dB, you would apply a 6 dB gain to the song as you play it. In theory, applying gain can be done losslessly. In practice, we don't deal with an infinite range of values, and so there will always be rounding error. The rounding error is basically unnoticable, but it's important to remember of it's existance because it does add up over time, if you keep applying gain and changing a file's actual audio data over and over again.
MP3Gain will get the RG value from an MP3 track and apply a gain that's reasonably close to bringing the song to a standard. MP3Gain is limited by the fact that it can only adjust the gain in 1.5 dB increments, but it's a winner in that it can do so totally reversibly. Changing the gain using MP3Gain over and over again does not cause any degradation or additive rounding error. This is because it's not modifying the actual audio data, but modifying gain values in the MPEG stream itself. Changing the gain does change the stream, so in that sense it does change the audio in the file, but it doesn't change the actual substance of the audio, and so it's reversible and/or non-lossy. Since the stream is actually changed, all audio players will support it, and since it has tags, some players will support it more exactly.
WAVGain is a program that will scan for the RG value and apply a gain to the actual audio data in the WAV. It does this in a way that's similar to "normalizing". Figure out what gain you want to apply, convert this to a multiplier, multiply every sample in the WAV by that value. This *does* produce rounding error, and so it is technically lossy. Do it once, you probably won't hear it. The errors will be on the order of one bit, and that's way below anybody's hearing capability. Do it over and over again, eventually you will hear it, as the errors add up and tend to flatten the waveform. Advantage of adjusting gain with WAVGain is that it is exact. It's not limited to the 1.5dB steps that MP3Gain is. Disadvantage is the rounding error problem. For burning a bunch of songs to CD and levelling them, then decompressing/copying to WAV, WAVGaining, and burning them is not a particularly bad idea. Just delete the modified WAV's after you're done.
Other ReplayGain methods are usually lossless in their entirety. The normal method is to add a tag to the file that specifies the desired gain and/or the track's RG value. With this information, a player that's capable of reading it (foobar, others) can apply gain on playback directly. This is the best way to do it, because it doesn't mess with the audio data, there's no additive error, and it's as exact as the resolution of your sound card is. But it does require player support and proper metadata tagging standards. As such, a lot of players do not yet support it.
Which to use:
-If you're burning to CD: Decompress the stuff to WAV and WAVGain it, then burn the WAVs and delete them from the hard drive.
-If you're putting stuff on an MP3 portable player: MP3Gain the lot. Use Track or Album Gain as you see fit.
-If you're ripping from CD: Rip and compress with no modifications like WAVGain. You ideally want to compress the original source as clean as possible, to remove possible rounding error later. MP3Gain the resulting compressed file if you feel the need to do so.
-Not using MP3: Use players that can scan for RG, store it in tags, and apply it properly. |
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b0b
From:
Cloverdale, CA, USA
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Posted 22 Jun 2008 12:11 pm
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That sounds like a very useful utility, Mitch. I'm using AAC instead of MP3, and I'm on a Mac, but it looks like there's might be a version that I could use. I guess a backup of the directories would be a good idea before starting something like this.
I was sort of hoping that there was an easy iPod trick for normalization. Guess not. 
_________________
-πππ- (admin) - Robert P. Lee - Recordings - Breathe - D6th - Video |
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Randy Phelps
From:
California, USA
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Posted 22 Jun 2008 12:56 pm
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whoa! you need go no farther than the preferences in itunes.
under playback choose 'soundcheck' it will set all your songs to the same volume. it will take a bit if your library is large. |
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b0b
From:
Cloverdale, CA, USA
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Posted 22 Jun 2008 4:46 pm
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That sounds like the right thing, Randy, but when I tried it, it only looped through 54 items. It included all of my Podcasts, but didn't bother with any of the tunes I've imported from CDs (which is the bulk of the collection).
How does it decide which songs to "soundcheck"?
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-πππ- (admin) - Robert P. Lee - Recordings - Breathe - D6th - Video |
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b0b
From:
Cloverdale, CA, USA
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Posted 22 Jun 2008 4:56 pm
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| Ah! I found it in settings menu of the iPod itself, a "Sound Check" switch. I never knew what that did before. I'll let you know how it turns out after I've done some more listening. |
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Randy Phelps
From:
California, USA
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Posted 22 Jun 2008 9:26 pm
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| bueno. |
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David Wright
From:
Pilot Point ,Tx USA.
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Posted 26 Jun 2008 5:29 am
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| Does the I~Phone have it to?? |
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Greg Simmons
From:
where the buffalo (used to) roam AND the Mojave
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Posted 27 Jun 2008 12:25 pm
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David - yes, on the iPhone, turn Sound Check on or off under Settings->iPod
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<i>Γ―ΒΏΒ½Head full of this kaleidoscope of brain-freight, Heart full of something simple and slowΓ―ΒΏΒ½</i>
-Mark Heard
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