Lame is possibly the most advanced and highest quality mp3 encoder there
is, continually developed, dMC always ships with the latest version. When
converting to Mp3 (Lame) the following option page is shown:

The
green bar represents the Bitrate bar, this is the quality of the
resulting mp3 file, higher bit rates files
are of a higher quality than lower bit rate files.
Optimum Settings
To quickly set lame to its
best - set both Channels and Frequency to [as source] and click Advanced
Options, under Presets select one of the Alt presets such as
ALT Preset Standard. It is the ALT presets that give the highest quality
for file size, there are a variety to choose from to alter the final
size and quality. It should be noted, most Alt presets use VBR
(see below), your mp3 player (if an older portable) might not like VBR
encoded files.
All the Settings
Frequency - number of samples per second to be
encoded, [as source] will set the final frequency to the source
frequency (44.1KHz for Audio CDs).
Channels
- Stereo - two channels of sound, enables instruments to appear
separated from one another.
- Mono a recording with only a single channel of information. A
question that is often asked Why is my 128kbps encoded
Mono file, not half the size as a 128kbps encoded Stereo file? The
answer is simple, to keep the Kbps rate constant, the mono file is
encoded at twice the quality rate as the stereo file (Kbps measurement
is for the whole recording regardless of the number of channels, so Per
Channel Kbps = Kbps / Number of Channels).
- Joint Stereo - Luckily for compression of Mp3's sound on the
left channel is very similar to sound on the right channel, Joint Stereo
takes advantage of this similarity to use the savings on the 2nd channel
to give higher quality compression.
- [as source] set the channels to
that of the source (2 for Audio CDs), if 2 channels then Joint
Stereo is used.
Advanced Options
On the Advanced page lurk options to tweak with the
innards of your mp3 files, there is:
Encoding - Mp3 files fall into these distinct categories:
Constant Bit Rate (CBR), a constant bit rate is
used throughout the encoding process.
Variable Bit Rate (VBR). Mp3 files are made up from 100's of
small audio chunks, called frames. Whilst encoding a VBR file, the
encoder decides which bit rate to use for each frame. Bit rates can drop
down to lower value when it is warranted (if there is not much sound
going on), and switch up to a higher bit rate when required. VBR files
are great when a compromise between file size, and quality has to be
made. VBR Options
- a Minimum
Bit Rate and a Maximum Bit Rate are specified by clicking
the left and right mouse buttons on the green bit scale. Next to
'Variable Bit Rate' is Quality 'Low ---- High' this controls the quality factor
for VBR.
Average Bit Rate a little like VBR except with
VBR the end file size is not known (could be small, could be big), ABR
is VBR with known end file size, it works by regulating how variable the
compression is, so at the end of the compressing the average is exactly
the value specified.
Preset Quality there exist nice people out there who
have done all the work in determining settings for various qualities, be
aware though many of these presets over-ride certain other settings, so
don't be surprised if you cannot alter say frequency after setting a
preset.
Set Bits
Copy write marks the mp3 file as containing
copywrite material.
Original marks the mp3 file as an original file (not a copy).
Private - the mp3 is private.
Write CRC Checksums will add a little checksum code
to each frame of your Mp3 file, so the decoder can tell if it has become
corrupted.
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