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Totty1987
Jun 25, 2012, 02:41 PM
I'm looking to adjust the bitrate of my iTunes library, but I'd like to know which format (AAC or MP3) is better at 128kbps.



nuckinfutz
Jun 25, 2012, 02:43 PM
AAC easily

ppc_michael
Jun 25, 2012, 03:05 PM
At 128kbps I have a really hard time discerning between MP3 and AAC as they both sound pretty crappy to me at that bitrate. But I guess if you look at the numbers AAC performs slightly better in that area.

gnasher729
Jun 25, 2012, 04:34 PM
I'm looking to adjust the bitrate of my iTunes library, but I'd like to know which format (AAC or MP3) is better at 128kbps.

Before you permanently destroy the sound quality of your music, note that iTunes can adjust the bitrate while it puts music onto your iPod, iPhone, or iPad, leaving the contents of your library intact.

Ariii
Jun 25, 2012, 06:07 PM
AAC has a better encoding than MP3. If storage space is no object, go with AIFF, even though 4 albums usually take up 1 GB using AIFF. AIFF, if you don't know already, is a lossless format; if you don't know that either, then Google it. If you usually listen to YouTube for music, you probably wouldn't care that much and would see a sound boost in it. If you care a lot about audio quality, then the obvious choice would be to get the lowest-space lossless format you can find.

Zwhaler
Jun 25, 2012, 07:13 PM
AAC delivers better quality at the same bitrate as MP3. I personally wouldn't go lower than 320kbps if possible, but 256kbps, and 192kbps are good too. It comes down to the quality of your speakers, midrange speakers probably won't see much benefit above 256kbps.

TyroneShoes2
Jun 25, 2012, 08:39 PM
...If storage space is no object, go with AIFF, even though 4 albums usually take up 1 GB using AIFF. AIFF, if you don't know already, is a lossless format; if you don't know that either, then Google it....If you care a lot about audio quality, then the obvious choice would be to get the lowest-space lossless format you can find.If so, each of those "albums" would have to be about 23 minutes long. 4 album sides per GB seems a bit more accurate.

AIFF is not a compressed format; its like wav or SDII, and very similar to CD format. Since "lossless" and "lossy" are generally applied to compressed audio formats, referring to AIFF as lossless just muddies the waters. An uncompressed format is already "lossless" by definition.

And when is space never a consideration? When there are lossless compressed formats available it hardly makes sense to store audio in an uncompressed format, even if 2:1 or 3:1 is about the best they can yield. Since iTunes and other can use lossless formats without pre-rendering it seems like a no-brainer to use them instead.

What I find interesting, and what will improve the quality of the 256 kbps AACs in the iTunes store, is that Apple is requesting masters from artists represented there. IOW, if Apple can make a 256 kbps submaster from the original master rather than from a CD (which is how they originally built the library) the 256 submasters will be of much higher quality that the versions they have there now, because more important than the encoding rate is starting with a full-quality original. CDs, while uncompressed, are truncated in both bit depth and bit rate compared to most pro masters. Chaining the 256 encoding to higher bit depths and bit rates will reduce rounding errors within the AAC encoding process and preserve more of the original fidelity.

Julien
Jun 26, 2012, 05:27 AM
AAC has a better encoding than MP3. If storage space is no object, go with AIFF, even though 4 albums usually take up 1 GB using AIFF. AIFF, if you don't know already, is a lossless format....

Better yet use ALAC. It's the best of both, lossless and compressed. About 1/2 the size of AIFF and the exact same audio quality. Storage is dirt cheap and you don't have to re rip your CD's later if you decide you want higher quality.

Totty1987
Jun 26, 2012, 06:21 AM
Before you permanently destroy the sound quality of your music, note that iTunes can adjust the bitrate while it puts music onto your iPod, iPhone, or iPad, leaving the contents of your library intact.

How do I do this???

Julien
Jun 26, 2012, 08:22 AM
How do I do this???


http://photos.imageevent.com/williamjulien/eastbayshirt/websize/128kbps.jpg

Totty1987
Jun 26, 2012, 08:59 AM
Image (http://photos.imageevent.com/williamjulien/eastbayshirt/websize/128kbps.jpg)

Thanx

Anonymous Freak
Jun 26, 2012, 01:45 PM
AAC, definitely. 128 kbps is the highest bit rate where major differences in codecs can be noticed without specialized equipment. If you absolutely positively MUST save every MB of space by going with 128 kbps, go AAC.

(I most often listen to music on my iPhone while bike commuting, so with so much road/wind noise, 128 kbps is just fine, so I use the "downsample" check box. At home, I generally use 256 kbps AAC, with the occasional album ripped/transcoded-from-FLAC to ALAC.

iEvolution
Jun 26, 2012, 02:44 PM
AAC is definitely superior at 128kbps, however there isnt much of a difference from 192 kbps and higher between either codecs. This is through Bose OE head phones, Sennheiser HD485s and Klipsch Image ONEs.

For me I prefer at least 192 kbps mp3 format for compatibility with my other music players. Though since this is through iTunes my preference would be 128 kbps AAC, this is what I use with my nano because of lack of capacity.

There are other issues besides bitrate like the head phones you use and the digital audio chip in your player. The chip can make a significant difference as I find the 6th gen nano to actually sound better with 128 kbps AAC audio files vs my ipod classic in native format (mostly 256 kbps+ mp3 and 256 kbps AAC)

Totty1987
Jun 26, 2012, 02:59 PM
AAC, definitely. 128 kbps is the highest bit rate where major differences in codecs can be noticed without specialized equipment. If you absolutely positively MUST save every MB of space by going with 128 kbps, go AAC.

(I most often listen to music on my iPhone while bike commuting, so with so much road/wind noise, 128 kbps is just fine, so I use the "downsample" check box. At home, I generally use 256 kbps AAC, with the occasional album ripped/transcoded-from-FLAC to ALAC.

The source/original files are mp3. Won't they lose quality if I re-encode them to AAC.

gnasher729
Jun 26, 2012, 04:12 PM
The source/original files are mp3. Won't they lose quality if I re-encode them to AAC.

Definitely. That's why I recommended the iTunes setting that will only compress what it stores on your iPod, but leaves all the originals alone.

TyroneShoes2
Jun 26, 2012, 08:44 PM
...I most often listen to music on my iPhone while bike commuting, so with so much road/wind noise, 128 kbps is just fine...Well, just keep telling yourself that. Lots of people do, but I'm afraid they are all wrong. There is still a huge difference between even 256 kbps compressed AAC quality and uncompressed CD quality. Bass is either muddy or mostly MIA, cymbals are swishy, separation suffers, and stereo imaging is "undefined", to put it diplomatically.

I don't like Classical, but it doesn't work very well at all when compressed, because the dynamic range means the soft parts are pushed down into the quantization noise floor. I detest the analog/vinyl elitists, but we can't pretend they don't have an argument. CD-quality digital is probably acceptable even to golden ears, but I really detest the loss of quality from compressed audio, even though its really the only audio I ever get a chance to listen to. TV audio is all compressed; internet audio is all compressed. FM is noisy; HD Radio is good quality but an implementational nightmare compared to something like Pandora. About the only way other than going to a live concert to hear acceptable audio is to dust off the CD player, and I am NOT going to go back to 2001 just to do that.

We've all gotten used to the dumbing down of music. Compressed audio sort of "seems" OK when there is nothing to compare it to, but if you get the chance to A/B a CD track with the same track on AAC or MP3, the difference in quality is glaring.

Don't get me wrong; I love the portability of iTunes/iPod as much as anyone, I just really hate the compromises we have made to go there.

My goal is to try to go loss-less, but that is probably not in the cards quite yet; most of my library is from CD so I can re-encode, but it would balloon my library size to about 45 GB and be a giant PITA. But then it does give me an excuse to buy a Touch. :)

spacepower7
Jun 26, 2012, 08:55 PM
The source/original files are mp3. Won't they lose quality if I re-encode them to AAC.

What bitrate are your mp3s? and how small do you want to shrink them? If you goal is to shrink to 128, and your mp3s are 256 or above, the I would recommend 128 AAC. If your mp3s are 192, I would probably keep them as is.

Most of the double blind testing on the net agrees that going from full CD quality to 128, then AAC is better than mp3 at that bit rate. Once tests get to 192 or 256 and above, most people can't tell the difference.

Converting from mp3 is different than CD but it depends on the source quality. Just don't go from 128 mp3 to 128 AAC bc it's a waste.

Anonymous Freak
Jun 27, 2012, 09:26 PM
The source/original files are mp3. Won't they lose quality if I re-encode them to AAC.

What bitrate MP3? If you're talking about re-encoding to 128 kbps, you're losing quality, period. But if you want to get the best sound for the file size, AAC is the way to go.

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Well, just keep telling yourself that. Lots of people do, but I'm afraid they are all wrong. There is still a huge difference between even 256 kbps compressed AAC quality and uncompressed CD quality.

First, re-read my exact quote. When wearing sweatproof headphones while bike commuting in traffic with wind noise, car noise, often rain noise, etc, I can't tell the difference between full CD quality and 128 kbps MP3, much less 256 kbps AAC and CD quality.

Also, the vast majority of people are not audiophiles, and can't tell the difference between 256 kbps AAC and uncompressed. Even audiophiles have a hard time telling the difference between 320 kbps AAC and uncompressed. Do an ABX test with good quality headphones, and you may be able to tell 320. Do an ABX test with the standard headphones most people use daily, and I doubt even an audiophile would be able to tell 256.

Yes, I would love a world in which all of my music were available in lossless format, with all extras possible, yet only take up 5-10 MB per track. But we're not there yet. For mobile devices, if you want a reasonable amount of songs, you MUST make the tradeoff. It's not ignorance, it's not that people are 'wrong', it's reality.

Opinion is opinion. It's your opinion that 256 kbps is bad compared to uncompressed. It's not fact. Fact is that there is a measurable difference. Opinion is that the difference is enough to be below an individual's tolerable threshold. In my opinion, 256 kbps AAC is plenty for nearly every use, nearly every piece of music. In your opinion, it's not. But that opinion is up to each individual to make on their own. So telling people "they are all wrong" just makes you look like an elitist prick.

maestrokev
Jun 27, 2012, 09:51 PM
What bitrate MP3? If you're talking about re-encoding to 128 kbps, you're losing quality, period. But if you want to get the best sound for the file size, AAC is the way to go.

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First, re-read my exact quote. When wearing sweatproof headphones while bike commuting in traffic with wind noise, car noise, often rain noise, etc, I can't tell the difference between full CD quality and 128 kbps MP3, much less 256 kbps AAC and CD quality.

Also, the vast majority of people are not audiophiles, and can't tell the difference between 256 kbps AAC and uncompressed. Even audiophiles have a hard time telling the difference between 320 kbps AAC and uncompressed. Do an ABX test with good quality headphones, and you may be able to tell 320. Do an ABX test with the standard headphones most people use daily, and I doubt even an audiophile would be able to tell 256.

Yes, I would love a world in which all of my music were available in lossless format, with all extras possible, yet only take up 5-10 MB per track. But we're not there yet. For mobile devices, if you want a reasonable amount of songs, you MUST make the tradeoff. It's not ignorance, it's not that people are 'wrong', it's reality.

Opinion is opinion. It's your opinion that 256 kbps is bad compared to uncompressed. It's not fact. Fact is that there is a measurable difference. Opinion is that the difference is enough to be below an individual's tolerable threshold. In my opinion, 256 kbps AAC is plenty for nearly every use, nearly every piece of music. In your opinion, it's not. But that opinion is up to each individual to make on their own. So telling people "they are all wrong" just makes you look like an elitist prick.

+1, this has been debated way too often on hydrogenaudio.org, 256Kbps is beyond the threshold of most audiophiles and 128 satisfies most regular people who don't listen to music in rooms with padded walls.

donga
Jun 27, 2012, 11:17 PM
another vote for aac.

personally, i like 320kbps though. I've ripped and reripped so many times from 128, to 192, to 256, to 320. (still not done with 320). I should've just done it right the first time.

botwa
Jun 29, 2012, 05:24 AM
AAC. although I must say that if you intend to listen to actual music (not audio books or something) with that quality... it's just ear killing.

Julien
Jun 29, 2012, 06:10 AM
another vote for aac.

personally, i like 320kbps though. I've ripped and reripped so many times from 128, to 192, to 256, to 320. (still not done with 320). I should've just done it right the first time.

You should be doing it "right" and use ALAC (or FLAC). Then you would never have to do it again. ;) Now you have to look forward to re ripping again.:eek:

akbarali.ch
Jun 29, 2012, 08:47 AM
aac is better than mp3 encoding at lower bitrate like 128kbps, but when you increase the bitrate the quality gap decreases and high bitrate is enough to give quality output no matter what codedc is used.
Just like 5 guys sitting in small-car will experience different level of comfort in different make n model of the car, but those 5 guys sitting in any SUV of any make and model should sit comfortably.

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You should be doing it "right" and use ALAC (or FLAC). Then you would never have to do it again. ;) Now you have to look forward to re ripping again.:eek:

Yeah, that's true, whenever i rip my CDs i rip it using EAC and convert m4a lossless using iTunes, then in devices, use 128kbps switch to put on the phone and iTunes does the work for you. In future, if you plan to get higher capacity ipod or iphone you can always switch to higher bitrate, its good even in a situation where you have varying capacity players, in one you can use 128 and in another 256. its the same song going in 2 different places and itune manages it and play count is updated no matter where you listen.

gnasher729
Jun 29, 2012, 11:40 AM
You should be doing it "right" and use ALAC (or FLAC). Then you would never have to do it again. ;) Now you have to look forward to re ripping again.:eek:

And the thread starter asked how to best convert from 320 KBit to something lower :eek:

Julien
Jun 29, 2012, 04:23 PM
And the thread starter asked how to best convert from 320 KBit to something lower :eek:

I was replying to donga in post #20. I did offer the OP some useful help in post #10. Also I don't see where Totty1987 mentions he has 320kbps files in the OP or any other post in this thread. Maybe I'm just over looking it.

I'm looking to adjust the bitrate of my iTunes library, but I'd like to know which format (AAC or MP3) is better at 128kbps.

donga
Jun 29, 2012, 11:40 PM
You should be doing it "right" and use ALAC (or FLAC). Then you would never have to do it again. ;) Now you have to look forward to re ripping again.:eek:

those would be huge files. maybe just use the original wav files from the cd, no compression at all! ;) (except of course, they are already compressed from the original masters....)

it could go on and on and on... i guess it really just depends on personal preference, what you can tolerate, etc.

MagnusVonMagnum
Jun 30, 2012, 12:50 AM
I don't like Classical, but it doesn't work very well at all when compressed, because the dynamic range means the soft parts are pushed down into the quantization noise floor. I detest the analog/vinyl elitists, but we can't


I'm quoting this part first since it seems to be so relevant. You don't seem to knowing the difference between data compression and loudness compression. Loudness compression (the thing that kills the noise floor and makes everything LOUD) is something used by radio stations and mastering engineers (who are told to make things LOUD). Data compression is used to make file sizes smaller. It has no effect on frequency response itself. Rather, by removing information at lower bit-rates, the effects (air, warble, odd sounding cymbals, etc.), it is the wave form envelope that is corrupted, not the actual frequency response. At higher bit-rates, the differences are negligible and therefore inaudible (this starts to occur somewhere around 192kbps for AAC with absolute inaudibility at 256kbps and 256 for MP3 with absolute inaudibility at 320kbps).

Well, just keep telling yourself that. Lots of people do, but I'm afraid they are all wrong. There is still a huge difference between even 256 kbps compressed AAC quality and uncompressed CD quality. Bass is either muddy or mostly MIA, cymbals are swishy, separation suffers, and stereo imaging is "undefined", to put it diplomatically.

I've got a high-end system that would make most people's head swim in these forums and this blatant nonsense about 256kbps AAC having weak bass and swishing noises is just that. Nonsense. I've done ABX double-blind testing with 256kbps AAC and ALAC encodes of CDs and the differences are completely inaudible. Now if you start converting AAC to MP3, you will start creating audible problems since like succeeding tape generations, the loss of information will start piling up well into the audible spectrum. Convert once from lossless formats only whenever possible.

I'm also a musician on the side and record my music (at 24-bits for headroom) and it's the same thing. The 256kbps AAC versions sound identical to the 16-bit WAV ones. And don't tell me there's a loss of bass. That's simply untrue. I've got flat response to 25Hz on my home theater and 27Hz on my ribbon speaker stereo room setup. I've got bass coming out my hind quarter here and in the car and nothing is missing nor should it be. Nyquist (sampling rate) determines frequency response, not data compression. Don't confuse loudness compression with data compression.