Posted by
Hemos
on from the learn-more-about-it dept.
bullitB writes "For fans of the world wide patent conspiracy's latest audio format, the latest double blind AAC encoder comparison test results are in. If nothing else, this suggests much of the complaints regarding the iTunes Music Store's lossyness might be unfounded."
As a physicist, I'd just like to draw everyone's attention to the error bars on these charts. For the majority of the tests, it's possible to draw a horizontal line through the 95% confidence intervals of nearly all the points.
Hence, the conclusions declaring clear winners/losers in these cases are invalid. If 99% confidence intervals were used (which gives a better statistical test), I feel that no clear winners or losers would be drawn.
Be careful with these sort of studies - even though the author has used confidence intervals, he has failed to use them to infer the proper conclusions.
That said, it's awfully nice to see error bars on this sort of website. Simple data points give such a false sense of precision, I find...
Re:I'm not a doctor, but I play one on television
by
Golias
·
· Score: 5, Insightful
I used to think the same way as your friend, because in the 80s and early 90s there did not seem to be any chance that digital sources could sound as good as my favorite LPs.
Then I heard what good CD players can sound like, and realized that the harshness of CD audio had nothing to do with resolution, and everything to do with component makers cutting corners. Your friend might make the same discovery, if he goes to a good listening room with an open mind.
--
Information wants to be anthropomorphized.
Re:Audiophile opinion
by
Amiga+Lover
·
· Score: 5, Insightful
Oh there's definitely a difference in pure analogue vs cd quality vs lossy compression codecs. Just taking a compression ratio down to 96kbit will make most listeners wince when their favourite tracks are played
I think that's part of it for many people. We might not hear parts of the music just like we may not "see" parts of a video clip on the first run round, but after 3 years listening to Louis Armstrong direct from CD, hearing him on 128kbit MP3 can be harsh. Humans learn and learn well, and the repitition of that playing guarantees we'll hear things that we're not meant to! or rather, things that we don't need to in order to identify a particular artist and recording. But we don't just listen to something to identify it, we listen to enjoy. That's different.
Most of the time 128kbit is fine for me. 192kbit for the things I'm familiar with.
Re:iTMS music does NOT sound lossy
by
mhoward736
·
· Score: 5, Insightful
Bollocks! BUT...
If I listen to an MP3 or AAC file on my computer with its sound card and speakers (SB Audigy, Boston Accoustics) I can tell the difference between the same (160kbs) MP3 file and a (128k) AAC - the AAC sounds better. I can't tell the difference between the AAC and a WAV file however.
If I move up to my ($$$$) home stereo then I can easily tell the difference between the compressed and non-compressed versions of the same song. AAC still sounds better to me than MP3 however.
The difference here is money and environment, my office is a noisy place with all the computers etc running. My listening room is quiet and I spent a lot of time setting the stereo up so that its at its best.
I have not looked at OOG or any of the other formats so I can't comment on the relative merits of them.
Perspective
by
UnknowingFool
·
· Score: 5, Insightful
Not to quash anybody's personal opinion of AAC, there are a few things that we should note.
1) Most people can't tell the difference between formats that are similiar in performance.
2) Some people actually can tell the difference.
3) Some people are just posers who can't tell the difference but say they can.
4) Lastly, most people don't really care as long as it is convenient to use either format.
-- Well, there's spam egg sausage and spam, that's not got much spam in it.
Do you ask a car mechanic...
by
SnowDog74
·
· Score: 5, Insightful
For the chemical formula for internal combustion? No.
Likewise, I wouldn't go to the local audiophile shop to ask them about audio engineering-related issues.
After being accosted by about ten salespeople in ten minutes at a local audio store that sells everything from Sony ES, to Krell, Wadia, Sunfire and the like... I caught a sales rep in a bold-faced lie.
I was looking for a receiver without many bells and whistles, and he tried steering me towards Denon.
When I asked why Denon is "better", he replied, "Because they focus solely on making audio components unlike Sony."
I chuckled and asked him to explain to me the funadamental difference between the sample & hold buffers on a Sony DAC vs. a Denon DAC... Naturally, he had no clue what I was talking about.
The "double-blind" survey is somewhat misleading... but that being said, it's clearly not measuring which format is superlative... it's only measuring people's perceptions. And people were pretty much even on those various formats.
The study in question just shows that people cannot consistently tell the difference between AAC formats.
Now, I've read articles in audiophile magazines that insisted that SACD (Super Audio CD) was brilliant in comparison to CD. And every one of those articles was a load of crap.
Fundamentally, even the most "discriminating" audiophiles cannot tell the difference between 16-bit, 44.1kHz PCM (Pulse Code Modulation - e.g. AIFF, WAV, in the computer world) and the 1-bit, 2.7GHz DSD bitstream of SACD... nevermind the minute differences betweeen various AAC-enabled codecs.
Hell, I would challenge anyone to be able to tell the difference between 16-bit PCM and MPEG-4 AAC.
The AES (Audio Engineering Society) has stated that MPEG-4 AAC is perceptibly indistinguishable from uncompressed 16-bit, dual channel PCM (e.g. CD-DA spec audio).and I would wager any experienced audio engineer's pair of ears (my own included) against any consumer "audiophile" any day of the week.
My advice to the idle rich? Don't buy the $45,000 pair of speakers... instead buy yourself better hearing and some common sense.
My personal preference? MPEG-4 AAC. As a content creator intensely familiar with a variety of media standards including AES, NTSC, ISO, ITU-R/CCIR, etc. I believe MPEG-4 w/AAC (not Quicktime MPEG-4, mind you, but straight MPEG-4) is the superlative format for compressed audiovisual media.
However, for critical listening, only uncompressed audio is the way to go. The general rule of thumb is that higher bitrates are preferable over higher sampling frequencies. Frequency response roll-off is what you want to avoid. But in order to support the higher bitrates, you need a D/A Converter (DAC, Digital-to-Analog Converter) with an effective sample-hold buffer that can crunch the necessary data to make an accurate conversion of the digital source.
That being said, I'm going to begin digitally remastering my own compositions soon... and go straight from the 24-bit master to a 24-bit multichannel DVD-Audio format. Why? Even an audiophile deafened by the sound of their money burning a hole in their wallet can actually tell the difference between my 24-bit master recordings and the dithered 16-bit CD audio.
Slashdot Mirror
As a physicist, I'd just like to draw everyone's attention to the error bars on these charts. For the majority of the tests, it's possible to draw a horizontal line through the 95% confidence intervals of nearly all the points.
Hence, the conclusions declaring clear winners/losers in these cases are invalid. If 99% confidence intervals were used (which gives a better statistical test), I feel that no clear winners or losers would be drawn.
Be careful with these sort of studies - even though the author has used confidence intervals, he has failed to use them to infer the proper conclusions.
That said, it's awfully nice to see error bars on this sort of website. Simple data points give such a false sense of precision, I find...
Then I heard what good CD players can sound like, and realized that the harshness of CD audio had nothing to do with resolution, and everything to do with component makers cutting corners. Your friend might make the same discovery, if he goes to a good listening room with an open mind.
Information wants to be anthropomorphized.
Oh there's definitely a difference in pure analogue vs cd quality vs lossy compression codecs. Just taking a compression ratio down to 96kbit will make most listeners wince when their favourite tracks are played
I think that's part of it for many people. We might not hear parts of the music just like we may not "see" parts of a video clip on the first run round, but after 3 years listening to Louis Armstrong direct from CD, hearing him on 128kbit MP3 can be harsh. Humans learn and learn well, and the repitition of that playing guarantees we'll hear things that we're not meant to! or rather, things that we don't need to in order to identify a particular artist and recording. But we don't just listen to something to identify it, we listen to enjoy. That's different.
Most of the time 128kbit is fine for me. 192kbit for the things I'm familiar with.
Bollocks! BUT...
If I listen to an MP3 or AAC file on my computer with its sound card and speakers (SB Audigy, Boston Accoustics) I can tell the difference between the same (160kbs) MP3 file and a (128k) AAC - the AAC sounds better. I can't tell the difference between the AAC and a WAV file however.
If I move up to my ($$$$) home stereo then I can easily tell the difference between the compressed and non-compressed versions of the same song. AAC still sounds better to me than MP3 however.
The difference here is money and environment, my office is a noisy place with all the computers etc running. My listening room is quiet and I spent a lot of time setting the stereo up so that its at its best.
I have not looked at OOG or any of the other formats so I can't comment on the relative merits of them.
1) Most people can't tell the difference between formats that are similiar in performance.
2) Some people actually can tell the difference.
3) Some people are just posers who can't tell the difference but say they can.
4) Lastly, most people don't really care as long as it is convenient to use either format.
Well, there's spam egg sausage and spam, that's not got much spam in it.
For the chemical formula for internal combustion? No. Likewise, I wouldn't go to the local audiophile shop to ask them about audio engineering-related issues. After being accosted by about ten salespeople in ten minutes at a local audio store that sells everything from Sony ES, to Krell, Wadia, Sunfire and the like... I caught a sales rep in a bold-faced lie. I was looking for a receiver without many bells and whistles, and he tried steering me towards Denon. When I asked why Denon is "better", he replied, "Because they focus solely on making audio components unlike Sony." I chuckled and asked him to explain to me the funadamental difference between the sample & hold buffers on a Sony DAC vs. a Denon DAC... Naturally, he had no clue what I was talking about. The "double-blind" survey is somewhat misleading... but that being said, it's clearly not measuring which format is superlative... it's only measuring people's perceptions. And people were pretty much even on those various formats. The study in question just shows that people cannot consistently tell the difference between AAC formats. Now, I've read articles in audiophile magazines that insisted that SACD (Super Audio CD) was brilliant in comparison to CD. And every one of those articles was a load of crap. Fundamentally, even the most "discriminating" audiophiles cannot tell the difference between 16-bit, 44.1kHz PCM (Pulse Code Modulation - e.g. AIFF, WAV, in the computer world) and the 1-bit, 2.7GHz DSD bitstream of SACD... nevermind the minute differences betweeen various AAC-enabled codecs. Hell, I would challenge anyone to be able to tell the difference between 16-bit PCM and MPEG-4 AAC. The AES (Audio Engineering Society) has stated that MPEG-4 AAC is perceptibly indistinguishable from uncompressed 16-bit, dual channel PCM (e.g. CD-DA spec audio).and I would wager any experienced audio engineer's pair of ears (my own included) against any consumer "audiophile" any day of the week. My advice to the idle rich? Don't buy the $45,000 pair of speakers... instead buy yourself better hearing and some common sense. My personal preference? MPEG-4 AAC. As a content creator intensely familiar with a variety of media standards including AES, NTSC, ISO, ITU-R/CCIR, etc. I believe MPEG-4 w/AAC (not Quicktime MPEG-4, mind you, but straight MPEG-4) is the superlative format for compressed audiovisual media. However, for critical listening, only uncompressed audio is the way to go. The general rule of thumb is that higher bitrates are preferable over higher sampling frequencies. Frequency response roll-off is what you want to avoid. But in order to support the higher bitrates, you need a D/A Converter (DAC, Digital-to-Analog Converter) with an effective sample-hold buffer that can crunch the necessary data to make an accurate conversion of the digital source. That being said, I'm going to begin digitally remastering my own compositions soon... and go straight from the 24-bit master to a 24-bit multichannel DVD-Audio format. Why? Even an audiophile deafened by the sound of their money burning a hole in their wallet can actually tell the difference between my 24-bit master recordings and the dithered 16-bit CD audio.