LAME MP3 Recommended encoder settings

This section describes the Hydrogenaudio recommended settings to be used with LAME for highest quality MP3 encoding. These settings require LAME 3.98 or later (the latest stable version is recommended).

 

Quick start (short answer)

Best quality: "archiving"

-b 320. This is the strongest setting for MP3, with the lowest risk of artifacts. With the exception of a few situations, quality is rarely better than the highest VBR profiles described below. However, 'archiving' music using a lossy format like MP3 is never recommended – no matter how transparent the resulting files might sound. The alternative is to use Lossless formats like WavPack, FLAC etc. that allow true archiving, bit for bit like on the original CD.

High quality: HiFi, home or quiet listening

-V0 (~245 kbps), -V1 (~225 kbps), -V2 (~190 kbps) or -V3 (~175 kbps) are recommended. These settings will normally produce transparent encoding (transparent = most people can't distinguish the MP3 from the original in an ABX blind test). Audible differences between these presets exist, but are rare.

Portable: background noise and low bitrate requirement, small sizes

-V4 (~165 kbps), -V5 (~130 kbps) or -V6 (~115 kbps) are recommended. -V6 produces an "acceptable" quality, while -V4 should be close to perceptual transparency.

Very low bitrate, small sizes: eg. for voice, radio, mono encoding etc.

For very low bitrates, up to 100kbps, ABR is most often the best solution. Use --abr (e.g. --abr 80).
--preset voice is only available in the command line front-end, and is there for compatibility. It is currently mapped to --abr 56 -mm, so that means that the recommendation would be to encode in mono, and use ABR.

Detailed explanation (long answer)

VBR (variable bitrate) settings

VBR: variable bitrate mode. Use variable bitrate modes when the goal is to achieve a fixed level of quality using the lowest possible bitrate.
VBR is best used to target a specific quality level, instead of a specific bitrate. The final file size of a VBR encode is less predictable than with ABR, but the quality is usually better.
Unlike other MP3 encoders which do VBR encoding based on predictions of output quality, LAME's default VBR method tests the actual output quality to ensure the desired quality level is always achieved.
Usage: -V(number) where number is 0-9, 0 being highest quality, 9 being the lowest.
Example: -V2
Note: The switch --vbr-new, which enabled a superior VBR mode in LAME 3.97 and some previous versions, is no longer needed with LAME 3.98 as it is now the default VBR mode. However, if you're still using LAME 3.97 or older, you have to add --vbr-new to your commandline to use that mode.

Source: wiki.hydrogenaudio.org