# 128 AAC vs 128 MP3



## bjurusik (Apr 28, 2003)

So I ripped a song twice, one at 128 AAC and one at 128 MP3 ... the MP3 was actually smaller.  I thought AAC was supposed to produce both smaller, and better sounding quality files at the same bit rate.  Or do they just mean that a 96 AAC sounds the same as a 128 MP3?


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## Koelling (Apr 28, 2003)

128 is 128 kbs. The song files are the same size (or should be). The quality is the difference. Apple actually went back to the original artists for music so the loss experienced in making a CD isn't noticable. I can't tell the difference but that's what it is, quality at the same bitrate.


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## toast (Apr 28, 2003)

In terms of quality, 128 AAC is similar to 160 MP3. Hence, you gain quality and space with AAC.


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## monktus (Apr 28, 2003)

128 mp3 isn't great (in fact sometimes it can be pretty awful) compared to 160. I ripped Point by Cornelius at 128 AAC and the file sizes were quite good (less than a meg a minute) and it sounds lovely. I'm very happy that they finally added aac support to the ipod. All Apple need to do now (apart from set up billing for music store outside the US!!!) is give old ipod users in the fly playlists. Oh and maybe tetris!


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## bjurusik (Apr 28, 2003)

Geez I feel dumb, lol some CS minor I am.  Another question, will any of you rip your CDs higher than 128 AAC?  Is it really worth taking up the extra space?  I guess if Apple uses 128 I will too.


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## mr. k (Apr 28, 2003)

on macrumors.com a week back there was an article comparing aac and mp3 - it said that listeners with tuned ears could not  tell the difference between an mp3 above 256kbps ( anything lower and they knew it wasnt a cd ) but for aac the different point was 128kbps...  seems great, i can cut my library almost in half  
and does anyone know if its possible to turn mp3 into aac?  would be easier to reburn everything.


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## Gnomo (Apr 28, 2003)

> _Originally posted by mr. K _
> *does anyone know if its possible to turn mp3 into aac?  would be easier to reburn everything. *


I'm sure you can, but the real question is: Would you really want to?

If you already lost data due to compressing a wav into an mp3, would you really want to possibly lose even more converting it into a aac?  or even if you don't lose any data, you will still have a aac that doesn't sound as great as it could.  Personally all the songs that I can I'm re-ripping.


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## binaryDigit (Apr 28, 2003)

> _Originally posted by Koelling _
> *128 is 128 kbs. The song files are the same size (or should be). The quality is the difference. Apple actually went back to the original artists for music so the loss experienced in making a CD isn't noticable. I can't tell the difference but that's what it is, quality at the same bitrate. *



No, 128kbs is the bit _rate_ and _not_ a measure of size.   The compression ratio is related, but not the same thing.  If you have a higher bit rate, you are storing more data per given time frame, which means that you have to compress more data for given time frame.   So a higher bitrate sample will take up more space than a lower one FOR ANY GIVEN COMPRESSION CODEC.  However, different codecs compress with different efficiencies AND quality.  Both mp3 and aac are lossy algorithms, you actually lose data compared to the original.  The "magic" is in the codecs ability to decide what to remove and to do it in such a way as to make it inaudible as possible.



> _Originally posted by mr. K _
> *and does anyone know if its possible to turn mp3 into aac? would be easier to reburn everything.
> *



Sure, if you want worse quality than the original mp3.  As stated above, MP3 is a lossy compression, you lose information in the compression process.  This information is lost, as in can't be restored.  The algorithm relies on the fact that you won't "miss" the data that it chucked.  What that means in your case is that you want to compress something where information has been lost with another program that will toss even more information.  At best you'll have something no better than the mp3, most likely you'll get something a bit worse.  So if the point of moving to aac is to have smaller files with better fidelity, you have to go back to your originals.



> _Originally posted by bjurusik _
> * Another question, will any of you rip your CDs higher than 128 AAC? Is it really worth taking up the extra space? I guess if Apple uses 128 I will too.
> *



That's entirely up to you.  Play with different settings and see what you like.  Could be that 128 is fine, could be that you actually notice a difference and want to go higher.  This is highly subjective.  One other thing to keep in mind is that different music is affected differently by the algorithms, so death metal might sound fine, while baroque might sound better at a higher rate (or vice versa).  Also depends on what and where you listen.  If it's with an ipod with bud plugs, then a loss of bass due to lower bitrates might not matter.  Then again a loss of high end due to lower bitrates might be more noticable if you have a pair of Stax hooked up to your iPod vs listening to it over you car stereo.  So use 128 as a starting point and play play play until you find what is right for you.


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## Dime5150 (Apr 28, 2003)

I think i might have found a drawback from AAC vs mp3.

I've ripped some cds to 128k AAC and I find that intermittent in songs it tends to kinda "get quiet" thats the best way I can describe it. Can anyone else hear it? Its noticeable when I have the speakers up loud. You can hear it kinda fade to the back. I'm not sure how to explain it.


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## dave17lax (Apr 29, 2003)

> _Originally posted by Dime5150 _
> *I think i might have found a drawback from AAC vs mp3.
> 
> I've ripped some cds to 128k AAC and I find that intermittent in songs it tends to kinda "get quiet" thats the best way I can describe it. Can anyone else hear it? Its noticeable when I have the speakers up loud. You can hear it kinda fade to the back. I'm not sure how to explain it. *



I know you said it's hard to explain, but could you try? Like is it being encoded at a lower volume or is it just suddenly getting the wind knocked out of it? I unfortunately don't have time to play with this stuff like I used to. My fault I guess for working at a bank instead of pursuing my major (art)


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## Dime5150 (Apr 29, 2003)

Well I can best describe it as the song losing its volume. Its very subtle. I'm still trying to figure it out. I don't know if its the AAC format (i found it on 160kpbs and 128 kbps rips in the format) or if its something else like my computer. I've used headphones and my studio speakers and does the same. 

It is not like its losing its total volume in the encoding. It still sounds the same but like in some moments in the song it will do a "dip" in volume. It is real quick. I'm thinking half a second or so and it comes back.

I guess I have a discerning ear. I could always here the hiss and fuzz even on subtle mp3s. But if you crank a good rock song you can hear this AAC stuff. Its like it loses its thunder for a half second or so. I'm not sure still if its AAC i'm still trying to figure it out.


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## mightyjlr (Apr 29, 2003)

> _Originally posted by Dime5150 _
> *I think i might have found a drawback from AAC vs mp3.
> 
> I've ripped some cds to 128k AAC and I find that intermittent in songs it tends to kinda "get quiet" thats the best way I can describe it. Can anyone else hear it? Its noticeable when I have the speakers up loud. You can hear it kinda fade to the back. I'm not sure how to explain it. *



I think I'm hearing the same thing you are.  On my Sennheiser 600's I hear what you are explaining.  Sort of like a fading or pulsing of volume in certain parts of the song.  The AAC format definately sounds better than MP3 however, so I don't really mind.  So far I've downloaded about 50 songs from the Apple music service and they are all really great quality.  I am very pleased.  I wasn't a big stealer of music, mostly because the quality was almost always fairly bad.  Now I can download the music I want at CD quality or better.  Awesome.


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## toast (Apr 29, 2003)

iTunes 4, Sennheiser HD 570.

AAC encoding messes with - blank parts in King Crimson, Brian Eno and KLF tunes. :angry:


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## cabbage (Apr 29, 2003)

bah!
mp3's suck and i'm sure AAC sucks ass too.

Shorten
http://research.umbc.edu/~hamilton/shnlinks.html

FLAC
http://flac.sourceforge.net/


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## Dime5150 (Apr 30, 2003)

I was talking earlier about how I found that in AAC the files lose volume at times. Well I think I might have narrowed it down. 

I think while doing other cpu intensive tasks is when it happenend. I'm wondering if the cpu is taxed more when playing AAC's and somehow i was doing to much while playing them.

This is only a theory. 

Oh and also. I downloaded my first song from apple music service and I can't hear this problem at all on the song.


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## Langley (Apr 30, 2003)

What is AAC?  explain.....and why is it better?


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## Jason (Apr 30, 2003)

this took all of 3 seconds to find

http://www.apple.com/mpeg4/aac/


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## Langley (Apr 30, 2003)

Jason

Thanks.....I guess I'm a little slow...Jez


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## fryke (Apr 30, 2003)

Summing up... The bitrate decides what size the file will be at the end, because 128 kbps means kilo-bits-per-second, so a 3 minute song will always be 2880 Kb. Advanced encoders actually do VBR (variable bit rate), so your mileage may vary depending on the song's 'encodability' (can the decoder switch to a lower bitrate at some parts...).

Whatever Apple or the MPEG group says: AAC is - like MPEG 1 Layer 3 (MP3) - a 'lossy' codec. They say it's better than MP3, so you're able to get about the same quality at 128 kbps that you get with a 160 kbps MP3. So you save some space. That's why the new iPods are advertised as being capable of holding more tracks.


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## OmegaMan (Apr 30, 2003)

I've never heard AAC myself, but is the extension still .mp3, or .aac?

Any good sites, I can d/l some free aac examples...and can play 'em through itunes?

Since Im in Canada, the itune store doesn't work yet, ofcourse...


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## Fahrvergnuugen (Apr 30, 2003)

> _Originally posted by Dime5150 _
> *I think i might have found a drawback from AAC vs mp3.
> 
> I've ripped some cds to 128k AAC and I find that intermittent in songs it tends to kinda "get quiet" thats the best way I can describe it. Can anyone else hear it? Its noticeable when I have the speakers up loud. You can hear it kinda fade to the back. I'm not sure how to explain it. *



mine has been doing this since I upgraded to iTunes4. It does it with MP3s that I've had for years......
The songs sound like they are fading up and down in volume while playing. its very annoying.
anyone else have this problem?


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## Jason (Apr 30, 2003)

im wondering if its part of the automatic volume adjustment setting?


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## chabig (Apr 30, 2003)

> _Originally posted by binaryDigit _
> *No, 128kbs is the bit _rate_ and _not_ a measure of size.*



The bit rate is absolutely a measure of size! In this case, it means your file will require 128K bits for each second of music. Since any particular song's length is constant, a 128Kbps encoding will be the same size regardless of the codec. For example, a song that is 300 seconds long will require 128K * 300 total bits. Again, this is regardless of the codec.

Chris


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## Dime5150 (May 1, 2003)

> _Originally posted by OmegaMan _
> *I've never heard AAC myself, but is the extension still .mp3, or .aac?
> 
> Any good sites, I can d/l some free aac examples...and can play 'em through itunes?
> ...



aac files become .m4a.

Well all you have to do is throw in any cd and rip the track to AAC. If you can play AAC you can make them.


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## fryke (May 1, 2003)

The fading out and back in again is really a part of the automatic volume control. Just turn it off, it's better. Guess that's quite a bug of iTunes 4, or at least a very, very annoying feature. It _was_ better in iTunes 3...


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## tsizKEIK (May 1, 2003)

> _Originally posted by OmegaMan _
> *I've never heard AAC myself, but is the extension still .mp3, or .aac?
> 
> Any good sites, I can d/l some free aac examples...and can play 'em through itunes?
> ...



protected AAC files have .m4p extension.
ripped AAC files have .m4a extension


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## g3joel (May 1, 2003)

> _Originally posted by fryke _
> *The fading out and back in again is really a part of the automatic volume control. Just turn it off, it's better. Guess that's quite a bug of iTunes 4, or at least a very, very annoying feature. It _was_ better in iTunes 3... *



I too am noticing the same thing with some of my MP3s in iTunes 4, though I feel it has nothing to do with the "Sound Check" option at all. I've never, ever had that option checked in the preferences.

The volume seems to dip at specific points in a track... perhaps when it reaches a certain frequency, or something...?

It's a little annoying if you're listening closely, but I *suppose* it's something I could get used to


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## chabig (May 1, 2003)

> _Originally posted by OmegaMan _
> *I've never heard AAC myself, but is the extension still .mp3, or .aac?
> 
> Any good sites, I can d/l some free aac examples...and can play 'em through itunes?
> ...



Even if you can't get the iTunes music store yet, you can still rip some of your own CDs to AAC (aka .m4a for MPEG 4 Audio) and listen to them.

For info on AAC, try http://www.apple.com/mpeg4/aac/


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## melving8 (May 1, 2003)

> _Originally posted by toast _
> *iTunes 4, Sennheiser HD 570.
> 
> AAC encoding messes with - blank parts in King Crimson, Brian Eno and KLF tunes. :angry: *




I bought nine inch nail's "hurt" at the itunes store and the quite parts are seriously mess up... i think (or it could be intentional by the artist as well... I just started to listening to it). I'm guessing it's the AAC encoding... you can hear it at the 30 sec preview as well....


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## Dime5150 (May 1, 2003)

> _Originally posted by fryke _
> *The fading out and back in again is really a part of the automatic volume control. Just turn it off, it's better. Guess that's quite a bug of iTunes 4, or at least a very, very annoying feature. It _was_ better in iTunes 3... *



No i've never ever had that option on. 

As far as the Nine Inch Nails song that fading is apart of the song. I have it on CD. That is how it is mixed actually.


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## step (May 1, 2003)

maybe the cause for this is iTunes itself?!


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## OmegaMan (May 1, 2003)

> _Originally posted by Dime5150 _
> *aac files become .m4a.
> 
> Well all you have to do is throw in any cd and rip the track to AAC. If you can play AAC you can make them. *



Thanks man.

I realized that, about 10secs after i clicked "submit reply"!   

Another reason why I asked for a free AAC site, I thought that only the master copies (ie. from the studios) would sound better, than ripping from our own CDs.

*thinks* But since cd's are digital copies.....i guess that wouldn't be.

*thinks this time before clicking 'submit'*
::ha::


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## Dime5150 (May 2, 2003)

> _Originally posted by OmegaMan _
> *Thanks man.
> 
> I realized that, about 10secs after i clicked "submit reply"!
> ...



Yea the rips from cd's are better since no degradation comes from manufacture cd's from the studio etc.

I got my iPod today and they sure do sound nice on it. 

Oh and I'm not hearing any drop in volume in any aac files on ipod. I think i found out what it is. The sound "enhancer" in iTunes is the culprit. Under effects menu. if you turn it off you can't hear the volume dip.


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## Fahrvergnuugen (May 3, 2003)

I think you're right. i just disabled mine because I figured it was using extra cpu and i haven't noticed the volum dipping since.


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## fryke (May 4, 2003)

Hmm... Is there a patch that renames the 'Sound Enhancer' to 'Sound Wrangler' or sumthin'? ;-)


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## toast (May 4, 2003)

So is this true that the Sound Enhancer really eats up CPU ? How much please (%) ?


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