I want to peak limit MP3's.

I'm not sure if this is the same as nomalizing. I have used MP3Gain to adjust the volume to the "maximum no clipping" level. The problem is that there is always one or two transients that throw this off, causing the whole file to be reduced in volume by just one transient. This usually reduces the whole track by 1.5 or 3db, just due to one errant transient.

I want to either squash the transients, or ignore them and be able to set the other 99% of the track volume to the maximum without clipping. I don't think a compressor is quite right for this job, but maybe it is.

I hope I explained that correctly.

The end result I want is to get the maximum volume I can out of my portables.

Any ideas? Any software to do this? I just downloaded mp3trim which has a nomalising feature, but I haven't tried it out yet.

You could use an MP3 trimmer/joiner to cut out the offending part, and try scanning the file. You could observe how much mp3gain changes the volume, and apply that change manually on the original file.

edit: You might not need a joiner. Split/trim to three parts:

• 1. good
• 2. bad
• 3. good

You could scan 1 and 3 together in album mode.

I want to batch job this on about 5,000 files. I might just end up nomalizing them. I still would have the originals in FLAC.

Normalizing won't help. It will just bring the largest peak to 0dBfs (or user defined level). You need a compressor/limiter. Many people like L2 from Waves. just be very careful, to much and you've become a victim of the loudness race. Obviously this would not be a lossless procedure.

The better solution would be to process during playback. You could try using the adaptX plugin wrapper to use directX plugs like L2 with winamp or a winamp plugin compatible program. http://www.hydrogenaudio.org/forums/index....33&hl=multiband
is supposed to be pretty good too.

I hear there is are some dynamics processors available for fb2k.

As for the batch, easy enough with diskwriter or using the batch converter in soundforge.

Perhaps it is technically possible to adjust those problem frames. I'm no expert, but IIRC each frame contains a global_gain field. Mp3gain changes this equally in the whole file. Perhaps someone could write a program to perform dynamics compression by adjusting the global_gain values. It would be kindof a rough approximation due to the 1.5 dB steps though.

I was thinking it would be nice if I could tell MP3Gain to just ignore 1% of the transients. Or maybe even less, like .1%.

i kinda wish portable manufacturers would incorporate this feature on their own - i believe that portables are the prime reason for the loudness race crap in the first place (mini-hifi units in my opinion aren't the cause as they can handle a dynamic album almost as well as an expensive setup with more headroom - a squashed album will do one of these units more damage than a dynamic one at a higher volume).

i've experimented with complete mad flattening of some of my songs in as nice a sounding way as possible - i can get replaygains up to -11db even on classical music (this is just for fun... but it might help one day when i'm listening to a portable on public transport). of course, this is a bit much for 5000 songs, as you'd need to tweak the settings for each song...

generic question - do portables like iRiver, Karma, etc have enough CPU to apply a peak limit in realtime? possibly even a multiband compression? the loudness maximizing process i go through is rough on my p3 733, but one need not go that far.