AAC at 128 whether you want it or not?
I wanted to see how the different formats sounded compared to a store-bought CD. I chose Cold Play's God Put a Smile Upon Your Face. I had it from the CD at 192kbps MP3 and I downloaded it at 128kbps MP3, 128kbps AAC and 256kbps AAC from the Music Store to compare the four.
Before downloading the three, I set the importing preference to 128kbps MP3 and bought and downloaded the song. Then I changed the importing preference to 128kbps AAC and downloaded that. Then I set the importing preference to 256kbps AAC and downloaded that (or so I thought). After they were all downloaded, I checked the Get Info for all three of the downloads and they were all 128kbps AAC. So, unless I was doing something wrong, even if you selected MP3, you will get 128kbps AAC. And if you select AAC, the max bit rate is only 128kbps, no matter what you put in there. Maybe that higher bit rate capability is something not available yet, who knows.
The sound quality of the 128kbps AAC and the 192kbps MP3 are very, very close. On the 192kbps MP3, the highs are a bit crisper and clearer (such as cymbals and vocals) but this can be compensated for with tweaking the equalizer. It's a subjective comparison I know. Still, I'm more concerned with not being able to download a higher bitrate AAC or being able to download in MP3. Hopefully I just did something wrong in configuring the importing preferences. Anyone else have similar problems?
EDIT: {After looking at the Music Store site a bit more, I realized what the problem was. I'd been reading about the iPod and how it works with the different formats and bit rates and I made the mistake of thinking that the Music Store also downloaded music in those same formats/rates. So, this whole test was a misunderstanding on my part (that's what I get for trying to do all this with only 4 hours sleep). I can only notice the difference from 192kbps MP3 and 128 kbps AAV in a quiet room with a good set of headphones on so by and large, the AAV format is pretty good. It would be great if the format would work on home and car CD players though. I think what Apple is doing is great and I hope it catches on. This is a very good start.}
Before downloading the three, I set the importing preference to 128kbps MP3 and bought and downloaded the song. Then I changed the importing preference to 128kbps AAC and downloaded that. Then I set the importing preference to 256kbps AAC and downloaded that (or so I thought). After they were all downloaded, I checked the Get Info for all three of the downloads and they were all 128kbps AAC. So, unless I was doing something wrong, even if you selected MP3, you will get 128kbps AAC. And if you select AAC, the max bit rate is only 128kbps, no matter what you put in there. Maybe that higher bit rate capability is something not available yet, who knows.
The sound quality of the 128kbps AAC and the 192kbps MP3 are very, very close. On the 192kbps MP3, the highs are a bit crisper and clearer (such as cymbals and vocals) but this can be compensated for with tweaking the equalizer. It's a subjective comparison I know. Still, I'm more concerned with not being able to download a higher bitrate AAC or being able to download in MP3. Hopefully I just did something wrong in configuring the importing preferences. Anyone else have similar problems?
EDIT: {After looking at the Music Store site a bit more, I realized what the problem was. I'd been reading about the iPod and how it works with the different formats and bit rates and I made the mistake of thinking that the Music Store also downloaded music in those same formats/rates. So, this whole test was a misunderstanding on my part (that's what I get for trying to do all this with only 4 hours sleep). I can only notice the difference from 192kbps MP3 and 128 kbps AAV in a quiet room with a good set of headphones on so by and large, the AAV format is pretty good. It would be great if the format would work on home and car CD players though. I think what Apple is doing is great and I hope it catches on. This is a very good start.}
Comments
It just means that I can play the songs on my computer or my iPod but not on the CD player in the car or in my stereo (without going to the Advanced tab and converting it to MP3 and having the sound quality drop even more).
Originally posted by Luca Rescigno
Well, one could assume that "importing" refers to any time you move music from an outside source to your iTunes library.
"w00t (or however it is spelled). Then I want to import it as AIFF."
The above senario is why it should be clear that you can´t choose the bit rate yourself. All people with the bandwidth would start downloading 600 mb+ CDs, making the load experienced by the Apple servers yesterday a quiet day.
Originally posted by EdinLA43
The sound quality of the 128kbps AAC and the 192kbps MP3 are very, very close. On the 192kbps MP3, the highs are a bit crisper and clearer (such as cymbals and vocals) but this can be compensated for with tweaking the equalizer. It's a subjective comparison I know.
Lol, that's impossible. All 3 files u downloaded are exactly the same!
Originally posted by eVo
Lol, that's impossible. All 3 files u downloaded are exactly the same!
(S)He got the 192kbps MP3 from the CD, not the Apple Music Store.
Cyan = source AIFF
128 kbps mp3, 100 kbps mp3pro, 128 kbps aac represent the other 3 plotted curves...
Can you identify which is which? The closer the curves match the Cyan line, the better the sound.
Originally posted by Eugene
The closer the curves match the Cyan line, the better the sound.
Please don't do that.
There is no corellation between the two.
Think about it for a second. Psycho-acoustic encoders reduce file-size by throwing away (and sometimes adding) noises that humans can't hear. How can you tell from looking at that graph which parts humans are sensitive to.
For you visual types: JPEG throws away more blue information than red, or green because that is the color humans are least sensitive to. Would a graph showing how much red, green and blue was removed from a JPEG tell you anything about picture quality without you actually looking at the image. (Remember that JPEG achieves great compression with no artifacts on natural 'photographic' images but does terrible on unnatural ones like screenshots)
thank you.
the real measure of how well a compressed format sounds is related to how the compression algorithms cut out those "unhearable" frequencies.
Originally posted by pesi
stupider...likeafox:
thank you.
the real measure of how well a compressed format sounds is related to how the compression algorithms cut out those "unhearable" frequencies.
You and stupider make it sound like one size fits all. Here's the problem. Once you lose the detail, you can't get it back in the case of JPEG, AAC and MP3. Don't try to pass my rant off as unfounded. If you can't hear the differences between a 192 kbps mp3 and ~1400 kbps CD-A, then good for you. Unfortunately, some of us can hear the difference. If you want smaller file sizes, stick with 128 kbps aac. More power and storage space to you, but that is not acceptable as the only option. You can alway reencode the already encoded material to get rid of that nasty extra bit you can't hear. It doesn't work the other way around.
Who cares that your output file would be even more lossy as a result? Te lossier the better! We couldn't hear the difference anyway!
Why should I pay CD prices for massibely sub-CD quality sound?
Originally posted by Eugene
You and stupider make it sound like one size fits all.
No we didn't.
We pointed out that using a spectrum analyzer to compare the quality of a psychoacoustic audio codec's perceptual model is dumb.
If you want to argue about that go ahead, the rest of your post has nothing to do with what I posted (but is mostly audiophile nonsense).
If you want to read up about audio compression try the forums at www.hydrogenaudio.org
Just don't post that graph or they will tear you a new arsehole.
Originally posted by stupider...likeafox
Think about it for a second. Psycho-acoustic encoders reduce file-size by throwing away (and sometimes adding) noises that humans can't hear. How can you tell from looking at that graph which parts humans are sensitive to.
A human doesn't have to hear the difference to know the waveform is different. How do you know what I'm incapable of hearing anyway? This is merely visual evidence of data-loss in addition to a listening test.
There's an acceptable threshold...128 kbps isn't it. It's better to compress too little rather than too much.
Were it otherwise, we'd all be running around with DAT players...
Originally posted by Eugene
How do you know what I'm incapable of hearing anyway?
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This is merely visual evidence of data-loss in addition to a listening test.
...
There's an acceptable threshold...128 kbps isn't it. It's better to compress too little rather than too much.
Your hearing may be great but your eyes need work because at no point in my post did I claim to know what you can hear, nor would it make any difference to my point if I did know.
However, large collections of statistics and many years of medical research tells me what people can hear.
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We don't need 'visual evidence of data-loss'. We know there is data loss. That is what psychoacoustic lossy(!) audio codecs are designed to do: lose data.
As for your claimed "listening test", I assume it was done double-blind to rule out the placebo effect that so often misleads audiophiles? Or did you just hear what you want to hear, and disregard the rest?
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Why the hell would Apple want to accept your subjective opinion when you claim to have hearing that is statistically exceptional?
Apple's done the research and the quality will be more than most people need or want.
If you claim to speak on behalf of the entire customer base then you'll have to do better than "128kbps AAC is rubbish"
Originally posted by stupider...likeafox
How can you tell from looking at that graph which parts humans are sensitive to.
Humans ears are sensitive to 20Hz-20kHz (roughly). We can still feel sound outside of this range (especially <20Hz) if it's loud enough, we just can't hear it.
Originally posted by Whisper
Humans ears are sensitive to 20Hz-20kHz (roughly). We can still feel sound outside of this range (especially <20Hz) if it's loud enough, we just can't hear it.
They're even discovering that sounds above 20kHz make a difference too, and that's why LPs sound better. The theory is that the sounds too high to be heard still bounce around the room long enough to fall within the range of human hearing.
Originally posted by tonton
Tell you what, Eugene:
Next time you come to Hong Kong and well have a little test. Three codecs (128 AAC, 192 MP3 and AIFF from original CD), 10 songs (chosen at random from your iTunes playlist), from your Mac to any sub-$10k stereo system available to you. At 8PM after a day of shopping, if you can get 3 out of three on 7 of the 10, I'll buy you a new 10GB iPod. If you lose you buy me one.
I'm in.
PRO NOBLEM.
Same goes for when you come to the UK.
(Have to add that as a 'perceptual' codec, AAC is damn good)