[sclug] [Fwd: Make my mp3s louder]

John Stumbles john at stumbles.org.uk
Tue Apr 22 21:06:09 UTC 2008

Neil Haughton wrote:

> The trouble is that a number of the CDs are noticably quieter than I
> would like. I'm talking average level here, so it's not a dynamic
> compression issue. My recently purchased remastered Roxy music albums
> are a case in point.

Dunno if this helps:

The Problem
Not all CDs sound equally loud. The perceived loudness of mp3s is even 
more variable. Whilst different musical moods require that some tracks 
should sound louder than others, the loudness of a given CD has more to 
do with the year of issue or the whim of the producer than the intended 
emotional effect. If we add to this chaos the inconsistent quality of 
mp3 encoding, it's no wonder that a random play through your music 
collection can have you leaping for the volume control every other track.

The solution
There is a remarkably simple solution to this annoyance, and that is to 
store the required replay gain for each track within the track. This 
concept is called "MetaData" data about data. It's already possible to 
store the title, artist, and CD track number within an mp3 file using 
the ID3 standard. The later ID3v2 standard also incorporates the ability 
to store a track relative volume adjustment, which can be used to "fix" 
quiet or loud sounding mp3s.
However, there is no consistent standard by which to define the 
appropriate replay gain which mp3 encoders and players agree on, and no 
automatic way to set the volume adjustment for each track until now.
The Replay Gain proposal sets out a simple way of calculating and 
representing the ideal replay gain for every track and album. Read on to 
find out more, or see what's new.


See also man:lame
  Compute ReplayGain fast but slightly inaccurately.
  See also: --replaygain-accurate, --noreplaygain
  Compute ReplayGain more accurately and find the peak sample.

John Stumbles

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