Wednesday, November 18, 2009

Is there really a benefit in lossless audio formats?

Lossless codecs are all the rage amongst those who aspire to be audiophiles.  Whether it is ripping CDs in a format like FLAC or WMA Lossless or listening the TrueHD track on Bluray movies, there are those who swear by it.   Most audio formats like MP3, AAC, and WMA are lossy formats.  They compress the audio by throwing away parts that humans theoretically cannot hear.  This is called “perceptual coding.”  Lossless codecs don’t throw away any information but instead compress more like Zip.  Lossless formats require a lot more space to store and a lot more bandwidth to transmit.  Are they worth it?  Can people really hear the difference?

TrustedReviews says no.  They go so far as to suggest than anything over 192kpbs MP3 is virtually impossible to differentiate.  “[A] few people in the last six months or so - people who take their audio gear seriously and have spent thousands of pounds on Hi-Fi equipment - have admitted privately to us that 256kbps MP3 is easily good enough for serious listening, and that they struggle to hear much difference over 192kbps MP3 in many situations.”  They conducted some A/B listening tests to see if ordinary people could perceive a difference.  The results did not support the extra expense and size of lossless formats.  In fact, most people couldn’t even differentiate between the 192kbps MP3s and a FLAC encoded version of the same songs.  The test wasn’t scientific, but there’s a pretty good chance it matches what those reading this blog will experience. 

Considering that most people listen to their music in noisy environments, on suboptimal speakers, or on tiny headphones from an MP3 player like the Zune, the chances they will ever be able to perceive the differences in audio are quickly diminishing. 

The short of it:  don’t waste the space ripping everything to lossless unless you plan to do a lot of transcoding in the future.  Don’t go out of your way to get a TrueHD movie setup.  AC3 is going to be just fine.

9 comments:

  1. So what's your point?
    Don't waste money on quality food, mac donald is good enough? :D

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  2. A more appropriate analogy would be, "Don't waste your money on organic food.  The regular stuff is good enough." See here: http://www.reuters.com/article/scienceNews/idUSTRE56S3ZJ20090729

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  3. I think when it comes to comparing high bitrate lossy streams with lossless you might have a point. I could believe a claim that not many people can distinguish between a FLAC and a 300+kbps MP3. I suspect that most people would be able to tell the difference when switching quickly between a FLAC and a 128kbps MP3, with slightly above average gear.
    I can definitly notice the difference switching from AC3 to PCM on BluRay
    Of course to appreciate the difference you really need to spend $300 on a gold plated Monster HDMI cable.. Just kidding.. Now THAT would be a better example of a waste of money.

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  4. The test is mostly for "pop" music; does that assertion still hold true for "classical" music?
    I would not be so sure.
    More generally speaking, different kind of music will require a different quality level.

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  5. @Roberto, there was some classical in this test.  One of the 4 songs I believe.

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  6. Archive in a lossless codec, play in another codec.

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  7. I so disagreem I can hear the difference between lossless and mp3, I use ape files all the times for my hifi, why do you think the high end audio exists?

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  8. Seriously, this is something i have always wondered about. Take youtube for instance, most of the audio is terrible. Even in HD!

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  9. I agree with Jay Jay opinion Youtube is a very good example if you are talking about audio lost.

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