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This article is from the MPEG FAQ, by Frank Gadegast phade@cs.tu-berlin.de with numerous contributions by others.

43 Wait a second! I understand that Layer-3 has been an important asset to the MPEG-1 standard, to address the high-quality low bitrate applications. With the advent of the "low sample rate extension (LSF)" in MPEG-2, is it still necessary to rely on Layer-3 to achieve a high-quality sound at low bitrates? (MPEG Audio Layer-3 Applications)

Yes, for sure! Please, don't mix up MPEG-1 and MPEG-2 LSF. MPEG-2
LSF is useful only for applications with limited bandwidth (11.25 kHz, at
best). For applications with full bandwidth, MPEG-1 Layer-3 at 64 or 56
kbps per channel achieves the best sound quality of all ISO codecs.
For applications with limited bandwidth, MPEG-2 LSF Layer-3 provides
an excellent sound quality at 56 kbps for monophonic speech signals and
still a good sound quality at only 64 kbps total bitrate for stereo music
signals (with around 10 kHz bandwidth). The latest MPEG ISO listening
test (in September 94 at NTT Japan, doc. MPEG 94/437) proved the
superior performance of Layer-3 in MPEG-1 and MPEG-2 LSF.

 

Continue to:

• prev: 42 Why does the performance increase with the number of the Layer? Why does the standard define a family of audio codecs instead of one single powerful algorithm? (MPEG Audio Layer-3 Applications)
• Index
• next: 44 Tell me more about sound quality. How do you assess that? (MPEG Audio Layer-3 Applications)

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