- Apple Lossless - a lossless encoder meaning that no information is lost in the encoding process.
- iTunes Plus - a lossy encoder which encodes to AAC format, with VBR
- iTunes MP3 - a lossy encoder which encodes to MP3 format, with support for VBR
- Lame - an open source MP3 encoder which has a high reputation and supports VBR
Music
The music I am using for this test is Dire Straits - Brothers in Arms on CD. The reason I chose this CD is because of its high production quality and large dynamic range. Recent trends in music production have led to increasing levels of mix volume being applied to albums which leaves less room for subtleties in the music.
Lastly I am no music expert, and do not claim to have an especially good ear so the best advice I can give when choosing what encoders to use when comitting your CD's to a digital format is to test yourself and see what level of quality you are prepared to sacrifice over the amount of space you are willing to concede. Another important consideration is the range of devices you wish to play your music on - MP3 supports the broadest range as it is now a universal format, but because of it's age it is not the most competitive technologically speaking.
Encoder Settings
I turned Error Correction OFF for this test as it imports CD's a lot more quickly.
Apple Lossless encoder has no settings to speak of as its goal is to provide maximum compression with no loss of quality.
For iTunes Plus I used the defaults - 256kbps VBR as per the screenshot below:
For the Lame MP3 encoder, I used the 'Standard' preset which provides a good balance between quality and size.
File Size Comparison
The table below shows the size of the entire album after compression.
| Encoder | Size |
| Apple Lossless | 265MB |
| iTunes Plus | 102MB |
| iTunes MP3 | 89.5MB |
| Lame MP3 | 74.6MB |
Apple Lossless predictably is much larger than the other formats, but this comparison is not about size - rather it is about the tradeoff of size versus quality.
Listening Test
For my first listening test I had full knowledge of which encoder had encoded the audio I was listening to. The device I used for the test is an iPhone 3GS with the standard white apple headphones that came with it - not high end audiophile hardware by any means but good quality nonetheless and a fairly typical setup.
Here are the results (marks out of 30):
Apple Lossless | iTunes Plus | iTunes MP3 | Lame MP3 | |
| Track 1 - So Far Away | 10 | 9 | 7 | 8 |
Track 2 - Money For Nothing | 10 | 9 | 9 | 9 |
Track 4 - Your Latest Trick | 10 | 9 | 7 | 7 |
Total | 30 | 27 | 23 | 24 |
Apple Lossless gets full marks and delivered the full sound of the CD as you would expect. With careful listening I could distinguish points where all the other formats didn't quite deliver on the sound but I was being quite picky and overall all the formats gave great quality playback.
Blind Listening Test
For the blind listening test I got my son to create a playlist for each song, containing each of the different encoded formats in a random order - I used the same iPhone 3GS and standard white apple headphones for the test. Since I had no knowledge of which format I was listening to in the test, this could not bias my judgement in any way, however from my previous listening test I knew what the original sounded like so I had a reference point. The first song in the playlist I marked as 5 points, then marked subsequent songs relative to the first, then repeated the test again and remarked adding up the results for each song.
Here are the results. There is no maximum mark here so you need to look at these results relative to each other:
For the blind listening test I got my son to create a playlist for each song, containing each of the different encoded formats in a random order - I used the same iPhone 3GS and standard white apple headphones for the test. Since I had no knowledge of which format I was listening to in the test, this could not bias my judgement in any way, however from my previous listening test I knew what the original sounded like so I had a reference point. The first song in the playlist I marked as 5 points, then marked subsequent songs relative to the first, then repeated the test again and remarked adding up the results for each song.
Here are the results. There is no maximum mark here so you need to look at these results relative to each other:
iTunes Plus | iTunes MP3 | Lame MP3 | |
Track 1 - So Far Away | 9 | 10 | 8 |
Track 2 - Money For Nothing | 11 | 10 | 7 |
Track 4 - Your Latest Trick | 12 | 9 | 10 |
Total | 32 | 29 | 25 |
This was a difficult test because all the formats had good quality, but the results correspond to the bit rate fairly well.
Conclusion
Apple Lossless has a very high disk space requirement but doesn't necessarily justify it compared to the next best format - iTunes Plus. I would only recommend using Apple Lossless if you want to have maximum quality and have the option to convert to any other format in the future without losing quality or going through the hassle of re-ripping all your CD's again.
iTunes Plus looks to be the best format if you are happy to go the Apple route as very few other players support AAC.
iTunes MP3 puts in a respectable performance as does Lame MP3 considering it had the smallest file size. The iTunes MP3 Encoder has had some bad press in the past but I don't think this is justified as long as you use the higher quality settings that I used.
Overall the differences between all the formats were fairly minor and only noticeable when listening in ideal conditions.
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