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A Case For Lossy Music Formats

Are downloaded lossy files viable for loudspeaker and system evaluation?

By Michael Fay January 8, 2019

Case For Lossy Formats, Sidebar 1

Per the Library of Congress Sustainability of Digital Formats website

MP3 is the common name for MPEG Layer III audio encoding, and is defined in two ISO/IEC specification families (MPEG-1: 11172-3 and MPEG-2: 13818-3).

MP3 compression employs perceptual coding, an approach based on psychoacoustic models that permit the codec to discard or reduce the precision of audio components that are less audible to human hearing. The three classes of audio compression associated with MPEG-1 and -2 specifications are known as Layers I, II, and III; MP3 is shorthand for Layer III. Each higher level designation increases the trade-off between increased syntax and coding complexity, and improved coding efficiency.

An MP3 file created with a bitrate of 128 kbit/s is about 1/11 the size of an uncompressed Linear Pulse Code Modulated (LPCM) file at compact disk levels of quality (44.1 kHz, 16 bits deep). An MP3 file can also be recorded at higher or lower bitrates, with higher or lower resulting quality.


Case For Lossy Formats, Sidebar 2

Reference Track Sampler
Night Winds – Randy Dorman and Rick Harper
Calling Elvis — Mark Knopfler and Dire Straits
Some People — LeAnn Rimes
Can’t Find the Words – Kim Richey
Pop Culture – Thomas Dolby
I Will Remember — Toto
Poquito Mas – Infected Mushroom
Capricorn — 30 Seconds To Mars

You can find the full list of my favorite tracks here — look for the MF SysTune link.

I keep most of these tracks handy on various storage media and on one small, portable device. I have a tiny thumb drive on my key ring and a number of compilation CDs, but my favorite is a FiiO X1, high-resolution, lossless music player. This device is compatible with the lossless and lossy file types listed below, and unlike phones, tablets and most computers that use headphone outputs, it has a dedicated line-level output with excellent specs.

FiiO File Formats Supported
Lossless
APE (Fast): 192 kHz / 24 bit
APE (Normal): 96 kHz / 24 bit
APE (High): 96 kHz / 24 bit
FLAC: 192 kHz / 24 bit
WAV: 192 kHz / 32 bit
AIFF: 192 kHz / 32 bit
AIF:192 kHz / 24 bit
WMA Lossless: 48 kHz / 24 bit (to be supported by future update)
Apple Lossless: 192 kHz / 24 bit

Lossy Compression
MP3, AAC, WMA, OGG

FiiO Output Specs
THD + N ≤ 0.003% (1 kHz)
Frequency Response 5 Hz to 60 kHz
Crosstalk ≥101 dB (10 kOhms / 1 kHz)
Signal to Noise Ratio (SNR) ≥ 115 dBA
Dynamic Range ≥ 107 dB
Line Output Level 1.7 Vrms (10 kOhms / 1 kHz)


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About Michael

Michael Fay
Michael Fay

 
Michael Fay is owner/principal at GraceNote Design Studio, an audio, video and acoustic design consultancy; a sustaining member and graduate of multiple SynAudCon workshops; a member of AVIXA and the Acoustical Society of America; an SDVoE Design Partner; former Integration Division general manager and senior design consultant with Sound Image; and former editor of Recording Engineer/Producer magazine.
https://www.gracenoteds.com/

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