Page 1 of 1

MP3Gain

PostPosted:Sat Mar 28, 2009 4:55 pm
by SineSwiper
Just discovered this little program. I was actually looking for a normalizer, as I was really tired of the volume level of my older albums (which was originally recorded on analog gear) being lower than the more recent (15 years or newer) albums. But, I was expecting to have to run through a lossy normalization, since it would have to unencode it and reencode it.

Not with MP3Gain. It actually modifies the global gain setting on all MP3 frames to achieve the same effect without touching the MP3 data itself. Also, unlike most normalizers, it doesn't just take the highest peak in the song and normalizes it to the top. (I do that already when I rip any CDs, and obviously, it doesn't work all the time.) It will use a more complex formula to figure out how loud it sounds to the human ear.

And it works. My analog albums seem just as loud as my digital ones. (I had to raise the default level +7dB, but that was simple to do.)

I've since added the program (which originally works for Linux) to my music sort script on my file server. (Yes, I have a music sort script, and yes, it is pretty awesome. Next thing I'm going to do to it is make it handle those horrid filenames with underscores in them.)

PostPosted:Sat Mar 28, 2009 6:56 pm
by Kupek
You're probably losing dynamic range by doing this.

PostPosted:Sat Mar 28, 2009 10:05 pm
by SineSwiper
Depends on how the player processes it. You can still take a 16-bit soundform and process it on a 24-bit template with increased range. So, the pre-gain waveform is still on the MP3, but it gets put into a 24-bit waveform post-gain. Of course, I think I'm talking more about clipping than dynamic range.

Really, what's the difference between an analog recording that I have to turn up 7dB in the car versus an analog recording that I increase the gain to 7dB? Besides, I'll test it out for a while. If it ends up being a problem, all of the MP3s have their own undo dataset, so I can undo all of my changse.

PostPosted:Sun Mar 29, 2009 3:11 am
by Kupek
SineSwiper wrote:Really, what's the difference between an analog recording that I have to turn up 7dB in the car versus an analog recording that I increase the gain to 7dB?
Because in order to raise the volume of the song itself, the "lows" are brought higher. But the highs are as high as they can go, so there's less difference between the "high" and "low" parts of the song - less dynamic range. This is the "loudness war" that I thought was brought up here: http://www.turnmeup.org/

We had a thread a bit ago about Metallica doing this in their latest album: viewtopic.php?t=13248

It sounds to me like you're basically remastering songs to increase the loudness, which decreases the dynamic range.

PostPosted:Sun Mar 29, 2009 10:02 am
by SineSwiper
Kupek wrote:Because in order to raise the volume of the song itself, the "lows" are brought higher. But the highs are as high as they can go, so there's less difference between the "high" and "low" parts of the song - less dynamic range. This is the "loudness war" that I thought was brought up here: http://www.turnmeup.org/
You're still not answering my question quite right. The waveforms are the same, whether I modify the MP3 via MP3Gain or not. MP3Gain is not normalizing the waveform in the traditional sense. It's making changes in the MP3 frame headers to tell the player to play that frame louder. So, again, it would be like me turning up the volume on an analog album.

Besides, on its default settings it would actually bring DOWN the volume on most modern albums to the analog range. Even with the +7dB setting I have it (which was based on an average sampling of various modern albums), it still brings down the volume on some albums by a few dB. Also, keep in mind that MP3Gain will do its gain adjustments based on album, if you want, so that quieter songs don't get boosted overly high.