AAC 320 vs. AAC 320 VBR vs. MP3 320 vs. MP3 320 VPR
Mar 3, 2012 at 10:01 PM Thread Starter Post #1 of 15

JarQin

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Just trying to decide which format to rip my CDs in. I've been hearing mixed responses; some people say there is no audible difference, and some say VBR sounds better, which I don't see how this is. I care about the sound quality more than the size. I don't want to rip in lossless, as I can't tell the difference on an ABX test and I need the hard drive space this conversion will give me. Also, should I use the iTunes converter or XLD to convert my ALAC files into the 320 files?
 
Mar 4, 2012 at 1:38 PM Post #3 of 15

bowei006

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Quote:
Just trying to decide which format to rip my CDs in. I've been hearing mixed responses; some people say there is no audible difference, and some say VBR sounds better, which I don't see how this is. I care about the sound quality more than the size. I don't want to rip in lossless, as I can't tell the difference on an ABX test and I need the hard drive space this conversion will give me. Also, should I use the iTunes converter or XLD to convert my ALAC files into the 320 files?



yeah i hear the same thing all the time. i say just go with at least AAC 256kbps VBR. anything higher than that should really sound the same. you can first rip your CD in WAV. and then encode from that wav file into all those formats and then do ABX testing using foobar..i can almost guarantee you that you will spend the rest of your life trying to tell them apart. i can tell you that ..you can maybe hear that their is some...different gut feeling to some of them..but overal. very hard to tell apart if done correctly
 
Mar 4, 2012 at 2:05 PM Post #5 of 15

bowei006

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Quote:
I myself use .mp3 320kbps CBR. No risk with quality and the most widely accepted digital audio format.



that's a good one too but the question is, in all technicality, is there a noticeable difference in all that. if not, AAC 256kbps VBR could save a bit off space. MP3 is popular but most MP3's i find these days, are generally pirated internet copies, or are handed out in some way illegal due to copyright laws, iTunes uses AAC downloads. just saying.
 
Mar 4, 2012 at 2:28 PM Post #6 of 15

dippyboy_87

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I do not use AAC myself due to compatibility issues if i ever need to change my player. But I read somewhere a comparo between mp3 and aac. And it was really difficult to come out with a clear answer if one is clearly better than the other. It depends on the tracks of comparison. In some cases one sound better than the other ever so slightly and vice versa. While taking up space also depends on the track. There was no consistency in the result as to which occupy the lesser amount of space. So i personally decided not to take the hassle of going the AAC route.
 
Mar 4, 2012 at 2:33 PM Post #7 of 15

bowei006

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Quote:
I do not use AAC myself due to compatibility issues if i ever need to change my player. But I read somewhere a comparo between mp3 and aac. And it was really difficult to come out with a clear answer if one is clearly better than the other. It depends on the tracks of comparison. In some cases one sound better than the other ever so slightly and vice versa. While taking up space also depends on the track. There was no consistency in the result as to which occupy the lesser amount of space. So i personally decided not to take the hassle of going the AAC route.


yeah that's the problem :/ the real time algorythmns could take a bad end one time that produces a very very small somewhat heareable difference, in one but not the other and then vice versa sometimes.. AAC works well for me as I use iPod's. It is also "generally" less space taking than MP3 256kbps VBR so I just go that route. really go whatever, we are comparing one Golden Delicious Apple to another Golden Delicious Apple. They are very....a fricking golden delicioius Apple, one may be more perfectly shapped or something sometimes than the other sokmetimes...but in the end..you're comparing one of teh same type of apples(lossy compressed) to another of the same type. 
 
 
Mar 4, 2012 at 2:44 PM Post #8 of 15

Somnambulist

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I just use iTunes, and rip to ALAC. I used XLD for a bit (and still do to convert FLACs to ALAC), but after reading around a lot it seems a bit excessive if you've kept your CDs in good condition. A 2TB external HDD has enough room for countless lossless CDs, then you can make AAC copies for portable use etc.
 
May as well make a copy as good as the CD given storage capacity these days. I also don't see myself not using Apple for the forseeable future, so AAC would be fine. ALAC is just lossless and open standard now so easy enough to make other lossy versions from.
 
Mar 4, 2012 at 3:07 PM Post #9 of 15

bowei006

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Quote:
I just use iTunes, and rip to ALAC. I used XLD for a bit (and still do to convert FLACs to ALAC), but after reading around a lot it seems a bit excessive if you've kept your CDs in good condition. A 2TB external HDD has enough room for countless lossless CDs, then you can make AAC copies for portable use etc.
 
May as well make a copy as good as the CD given storage capacity these days. I also don't see myself not using Apple for the forseeable future, so AAC would be fine. ALAC is just lossless and open standard now so easy enough to make other lossy versions from.



+1 man. other people's arguments:Well apple sucks their stuff sucks their players are low quality. here is what i want for my DAP. good line out, good price to GB,good quality, decent headphone out if i need it, lossless playback ability and expandable storage. any suggestions?...other than expandable storage..you just named an ipod, and i shall say, price to GB is very nice on them
 
I use ALAC on my ipod touch and store the exact same songs but in AAC 256kbps VBR on my 4S. i do FLAC to ALAC encoding a lot with dBpoweramp on PC and Max on Mac OSX.
 
Mar 4, 2012 at 3:30 PM Post #11 of 15

TheGrumpyOldMan

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I went through this when I started re-organizing my library after getting into the whole head-fi thing. I also had the issue of (portable!) storage space vs. sound quality. I did a bunch of listening and in the end I went with this:
 
-- I'm using XLD for everything ripping & transcoding because it gives you way more control over every aspect than iTunes ever will, and I don't see how the quality will be any -less- since it uses the same OS libraries as iTunes for everything they both offer (AAC, ALAC) And it can dump the result straight into iTunes (just as if you were using iTunes' internal ripper/encoder).
 
Its ripper has advanced modes, incl. checking with a rip database (and btw. the "confidence" number you get in the log is the number of other rips in the database, took me a while to dig that up) It converts FLAC files extremely fast (at least on an SSD) It allows for album FLAC + cue sheet to be converted into song-by-song in any format. It can down-convert HQ FLAC files (24/192) to iPod compatible 24/48 ALAC very quickly, and most conveniently it supports Profiles, so you can make your own into a dropdown list ("Best lossy", "Original Lossless", "iPod Lossless" etc.) It also allows for file/folder formatting since I do not ever want iTunes to "manage" my carefully curated library... I just use it as a player, pointing at said library, and to copy things on my iDevices.
 
And if I ever tire of Apple, my whole music library is completely independent, I could use any other player (iBasso...) or software on Windows or Linux point at my master folder and I would have the whole thing up and running in no time. (Apple officially released the ALAC spec, not that it wasn't already completely reverse-engineered anyway, so it won't become unusable anytime soon)
 
-- My overall strategy is to use the best lossy format possible for most albums, and only use lossless for albums dear to my heart or very refined (classical, acoustic jazz) To be honest mostly for archival purposes because even on my current rig I can barely discern a difference between both, and only on certain tracks, if I really focus on it (which is not particularly enjoyable, which in turn is really the reason for all this in the first place - enjoy music)
 
-- As far as "best lossy" goes, my conclusion was to go with MP3 because it is more universally usable (i.e. independent of Apple) and from reading up on the subject, at -high- bitrates not inferior to AAC in any way. More importantly, the most widely used encoder, LAME, is in active development by enthusiastic people working to improve it continuously. I don't get that impression from Apple, they seem to be more focused on vending machine features these days than sound quality (ex.: the worsening SoundCheck debacle for example...)
 
Also there are more options available, all accessible within XLD. I went with the best possible variable bitrate setting, VBR0, said to be identical to CBR320 except by leaving out the unused bits yields a smaller filesize. (i.e. technically it is a smidgeon better than 256kbps VBR on either AAC or MP3) I did quite a bit af A/B(X) listening between a number of tracks in various genres, and I could NOT tell the difference between those two (VBR0 & CBR320) for any track -even once-, and I think my setup is decent enough that I should be able to.
 
Filesize-wise, lossless compression yields on average half the size of an uncompressed album, and VBR0 yields on average about 1/3 the size of a lossless album. That trade-off is ultimately the one that works for me for the looooong run (so many albums to re-rip
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)
 
UPDATE: Regarding MAX on OSX: I used it for a long time, love it but since it is no longer in active development, XLD does everything it does but better. I think I only ever once came across a format that XLD had trouble with, but MAX was OK so I still keep it around for such cases)
 
Mar 4, 2012 at 3:37 PM Post #12 of 15

Mython

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It also depends on how resolving your listening gear is - if you have a SpiralEar Reference 5-way being driven from a Weiss DAC202 via an SPL Phonitor amp, then you'll probably easily pick out differences between 320 AAC and 320 mp3    
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If, on the other hand, you're just listening to your files via an iPod and a <$100 pair of universals, then the difference may be largely imperceptible.
 
Even so, with HDDs being so cheap these days (yes, in spite of the profiteering going on in the supply chain, due to the floods late last year in Thailand), the best solution would surely be to buy a cheap 1tb or 2tb HDD and keep all your files in lossless.
 
After all, if you compress your entire music library to a lossy codec, there'll be no going back... which would be a waste and surely likely to (eventually)  lead to regret.
 
 
 
 
Mar 4, 2012 at 4:09 PM Post #13 of 15

TheGrumpyOldMan

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I agree on principle on the all lossless approach, at least for a local 3.5" harddrive (I keep a separate "Archive" folder for those) but for portable storage it is either not possible or expensive. I'd like to fit my music on an iPod Classic (there aren't many good HD-based players left, and which one would be over 160GB?) not so much because I need all my music all the time, but just to have a backup with me.
 
Online storage is a consideration for off-site backup, but it would take very long to get it up there, and of course the big problem with the "cloud" is if you get cut off (connection or outage), you have zilch, zip, nada...
 
Another consideration is the -source- quality. In another thread I wrote about a recent album that is so poorly mastered (DR compressed to hell) that there is simply -no- benefit whatsoever to keep a lossless version at 3x the wasted space for something that sounds so bad in the first place (the music is OK, so I'd like keep it in some form)
 
Apr 26, 2012 at 11:05 AM Post #15 of 15

YoengJyh

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This is what i found via Google... 
 
 
AAC is a wideband audio coding algorithm that exploits two primary coding strategies to dramatically reduce the amount of data needed to represent high-quality digital audio.

  • Signal components that are perceptually irrelevant are discarded;
  • Redundancies in the coded audio signal are eliminated.
The actual encoding process consists of the following steps:

  1. The signal is converted from time-domain to frequency-domain using forward modified discrete cosine transform (MDCT). This is done by using filter banks that take an appropriate number of time samples and convert them to frequency samples.
  2. The frequency domain signal is quantized based on a psychoacoustic model and encoded.
  3. Internal error correction codes are added;
  4. The signal is stored or transmitted.
  5. In order to prevent corrupt samples, a modern implementation of the Luhn mod N algorithm is applied to each frame[32]
The MPEG-4 audio standard does not define a single or small set of highly efficient compression schemes but rather a complex toolbox to perform a wide range of operations from low bitrate speech coding to high-quality audio coding and music synthesis.

  1. The MPEG-4 audio coding algorithm family spans the range from low bitrate speech encoding (down to 2 kbit/s) to high-quality audio coding (at 64 kbit/s per channel and higher).
  2. AAC offers sampling frequencies between 8 kHz and 96 kHz and any number of channels between 1 and 48.
  3. In contrast to MP3's hybrid filter bank, AAC uses the modified discrete cosine transform (MDCT) together with the increased window lengths of 1024 or 960 points.
AAC encoders can switch dynamically between a single MDCT block of length 1024 points or 8 blocks of 128 points (or between 960 points and 120 points, respectively).

  1. If a signal change or a transient occurs, 8 shorter windows of 128/120 points each are chosen for their better temporal resolution.
  2. By default, the longer 1024-point/960-point window is otherwise used because the increased frequency resolution allows for a more sophisticated psychoacoustic model, resulting in improved coding efficiency.
 

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