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Audio Comparison With Audacity and Quicktime Compression Codecs

For this audio comparison, I created 12 mono files from the 44,100Hz 16-bit mono benchmark file I created. It is part of a composition I wrote in 2004 -- with several instruments in high range during this 30 second bridge (between the verses). The audio consists of a woodwind secion, brass, electric guitar and percussion. I was particularly interested in how the instrumentation would degrade as the audio was compressed more, especially the trumpets.

   (16-Bit Mono @ 44100 Hz)          (flute/oboe, trumpets)
trumpets
There is a significant loss when the file size dropped below 100 KB. There is even a noticeable loss with the 215.47 KB Quicktime file. There is an unwanted flattening of audio dynamics with the higher compressions, to the point where one can no longer tell that there are trumpets involved -- or exactly what the instrumentation is. The mono file was taken from the Stereo file that I recorded. The entire composition was 25MB -- and compression would reduce this file size significantly.



Comparison of Different CODEC Audio Compressions
File File Size (KB) Compression Usage
Audacity U-Law 44100 Hz 1290.24 U-Law I would not use this file. It is too large.
Audacity A-Law 44100 Hz 1290.24 A-Law I would not use this file. It is too large.
Audacity IMA ADPCM 44100 Hz 646 IMA ADPCM I would not use this file. It is too large.
Audacity MPEG3 44100 Hz 470.20 MP3 This file is usable.
Quicktime MACE 3.1 44100 Hz 430.95 MACE 3.1 This file is usable.
Audacity MP4 44100 Hz 277.98 MP4 This file is usable.
Quicktime MACE 6.1 44100 Hz 215.47 MACE 6.1 I would not use this file. The quality isn't high enough.
Quicktime QDesign 24 44100 Hz 87.86 QDesign 24 I would not use this file. The quality isn't high enough.
Quicktime QDesign 20 44100 Hz 73.17 QDesign 20 I would not use this file. The quality isn't high enough.
Quicktime QDesign 16 44100 Hz 58.30 QDesign 16 I would not use this file. The quality isn't high enough.
Quicktime QDesign 12 44100 Hz 43.52 QDesign 12 I would not use this file. The quality isn't high enough.
Quicktime QDesign 10 44100 Hz 36.58 QDesign 10 I would not use this file. The quality isn't high enough.
It would be nice to use the stereo file, but its file size is too large (5.4 MB). I would choose one of these three compressions: MP3, MACE 3.1 or MP4, and would favor the use of the MP4 file due to its low file size. Even the MP3 file is OK. The question one should ask is: What file size should one limit the audio to? I think a range of 500 - 250 KB is OK. This would mean that the download times would be 1-2 seconds. For embeded files, this is significant -- as they will load when the website opens.