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Topic: At what bitrate is AAC *universally* transparent? (Read 25251 times) previous topic - next topic
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At what bitrate is AAC *universally* transparent?

Reply #25 –
Does anyone know a good killer sample for AAC?

I tried to ABX the "castanets" with AAC @ 192 kbs with my equipment and didn't succeed (9/16). With LAME at api I can even ABX the sample with 16/16!

At what bitrate is AAC *universally* transparent?

Reply #26 –
Quote
Do we also see things that are invisible?
[a href="index.php?act=findpost&pid=266506"][{POST_SNAPBACK}][/a]

Yes, it is usually called a hallucination.
Infrasonic Quartet + Sennheiser HD650 + Microlab Solo 2 mk3. 

At what bitrate is AAC *universally* transparent?

Reply #27 –
Still lacking hardware support and falling prices for storage seem to erode the AAC faction - AND then there also is all that DRM talk which makes people shy away... Recently, I purchased my first portable player and found out that actually the options you had for AAC playback have shrunk instead of become bigger. Add the fact that AAC's superiority over MP3 gets more impressive at lower bitrates but portables tend to feature 512+ MBs storage today, instead of the typical 128 MBs of the old days, and you run out of sane arguments for using AAC. It is a pity, the industry shot themselves in the foot. Even the sternest AAC fans, guruboolez and rjamorim have wandered off for those reasons.

Myself, I don't have logical reasons for sticking with AAC; I just trust Nero's 'extreme' preset more than LAME's 'extreme' preset and I consider lossless audio a bit of a waste of space.

Perhaps AAC support will catch up a bit when players for the successor of DVDs come out that should be able to play AAC, too. That should prompt in turn the market for AAC portables. But perhaps not, and in that case I'll just stick with transcoding AAC 'extreme' to MP3 'extreme' for use on Zen Touch player and indulge in my lunacy...

At what bitrate is AAC *universally* transparent?

Reply #28 –
Quote
I tried to ABX the "castanets" with AAC @ 192 kbs with my equipment and didn't succeed (9/16). With LAME at api I can even ABX the sample with 16/16!
[a href="index.php?act=findpost&pid=277926"][{POST_SNAPBACK}][/a]


I could abx it at aac 128kbps, but not 192kbps. It was a breeze with api 3.96.1. I also tried for fun with iTunes mp3 @ 192kbps, and that sounded almost as bad as the xing sample to my ears..


edit: quickly tried "fatboy" and that seemed to break the aac encoder pretty badly at 192kbps.

At what bitrate is AAC *universally* transparent?

Reply #29 –
I remember  the main goal of AAC was CD quality @96kbps (like mp3 @128kbps ). Maybe it´was a dream I had...in 10 years perhaps it´s true

At what bitrate is AAC *universally* transparent?

Reply #30 –
Quote
Quote
Do we also see things that are invisible?
[a href="index.php?act=findpost&pid=266506"][{POST_SNAPBACK}][/a]

Yes, it is usually called a hallucination.
[a href="index.php?act=findpost&pid=277934"][{POST_SNAPBACK}][/a]

A hallucination isn't invisible.... Your mixing up the terms here...
"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
        - Oceania Association of Autonomous Astronauts

At what bitrate is AAC *universally* transparent?

Reply #31 –
novocane, I remember hearing on one of the G4TechTV shows (The Screen Savers maybe?) that 96kbps near-CD quality really was the goal of MPEG-4 AAC.

The way I see it, at least AAC is a slight improvement (however slight) over MP3 at similar bitrates...unlike WMA which seems to be a step backward for everything except super low bitrates (<96kbps).  :-P

At what bitrate is AAC *universally* transparent?

Reply #32 –
Quote
I remember  the main goal of AAC was CD quality @96kbps (like mp3 @128kbps ). Maybe it´was a dream I had...in 10 years perhaps it´s true
[a href="index.php?act=findpost&pid=293590"][{POST_SNAPBACK}][/a]


I find it to be a marked difference between AAC @ 96kbps and 128kbps, at least with the QT encoder. It also says in the help file that they don't recommend using less than 128kbps for music. In other words, I don't think they aim for transparency at bitrates below 128kbps.
 

At what bitrate is AAC *universally* transparent?

Reply #33 –
Quote
A hallucination isn't invisible.... Your mixing up the terms here...
[a href="index.php?act=findpost&pid=293593"][{POST_SNAPBACK}][/a]

That was a joke, btw.
Infrasonic Quartet + Sennheiser HD650 + Microlab Solo 2 mk3. 

At what bitrate is AAC *universally* transparent?

Reply #34 –
With my speakers, I can tell the difference between 500kbps ogg and lossless. What's my point? Theres no such thing as real transparency, theres always someone that can tell the difference (eg: me). Universally transparent is an oxymoron. It's impossible. Besides, that's no what you want anyways. You want whats transparent to you. Do a listening test and decide for youself.

At what bitrate is AAC *universally* transparent?

Reply #35 –
Quote
With my speakers, I can tell the difference between 500kbps ogg and lossless. What's my point? Theres no such thing as real transparency, theres always someone that can tell the difference (eg: me). Universally transparent is an oxymoron. It's impossible. Besides, that's no what you want anyways. You want whats transparent to you. Do a listening test and decide for youself.
[a href="index.php?act=findpost&pid=293792"][{POST_SNAPBACK}][/a]


You're seriously able to ABX a 500kbps file from the source?    Whoa.


Quote
Does anyone know a good killer sample for AAC?

I tried to ABX the "castanets" with AAC @ 192 kbs with my equipment and didn't succeed (9/16). With LAME at api I can even ABX the sample with 16/16!
[a href="index.php?act=findpost&pid=277926"][{POST_SNAPBACK}][/a]


Good question; I agree that 192kbps is enough for castanets.  I thought long and hard about this and even tried a few.  I couldn't even ABX the infamous fatboy.wav "zipper" sound at 192kbps QT AAC-LC (although it had horrible artifacting at 128kbps).  Can anyone find or think of any other samples?  I'm really curious too.

At what bitrate is AAC *universally* transparent?

Reply #36 –
For some people (lossy) transparency is impossible. ABXing doesn't tell the whole story, because when you've compressed everything yourself you do know how it's been compressed, and for those perfectionists amongst us any lossy file will (seem to) sound worse, simply because they know it's lossy.

At what bitrate is AAC *universally* transparent?

Reply #37 –
Quote
For some people (lossy) transparency is impossible. ABXing doesn't tell the whole story, because when you've compressed everything yourself you do know how it's been compressed, and for those perfectionists amongst us any lossy file will (seem to) sound worse, simply because they know it's lossy.
[a href="index.php?act=findpost&pid=293884"][{POST_SNAPBACK}][/a]


Are you talking about a placebo effect?  If so, I'm not sure that's an objective statement about audio quality at all.

At what bitrate is AAC *universally* transparent?

Reply #38 –
Yes... I'm prejudice in my blind tests, lol.

At what bitrate is AAC *universally* transparent?

Reply #39 –
Quote
Are you talking about a placebo effect?  If so, I'm not sure that's an objective statement about audio quality at all.
[a href="index.php?act=findpost&pid=293915"][{POST_SNAPBACK}][/a]

The question wasn't when is it objectively transparent, it was when it's universally transparent. My point was that universal transparency isn't really relevant to an individual choosing how to archive files - he could ABX it personally, use an extreme preset or leave it lossless, but since it's impossible to be objective while listening outside of a blind test, psychological effects are going to play a part in the listening - I don't ever do lossy compression for that very reason - I've no idea how high I can ABX mp3/ogg/aac from the original (although some time when I have a nice PC audio set up I plan on doing some tests...) but when I'm listening normally it doesn't sound as good to me, so I only use lossless formats unless I'm sending stuff to other people to listen.

I think there have been tests done, and if there are I'm sure someone else could link you.