[warnbroom]

Think I've landed on the right place to start off this discussion..

So lately I've been asking myself which is better in terms of sound quality and spectrum generated. Someone hit me with the information that says songs on iTunes store are encoded straight from the recording source, hence produce superior quality to those encoded from CD. Is this really true ? And is it the main factor to say it's completely better than CD ripped quality ?

That said, would it be correct to think that even at the highest encoding settings on iTunes itself, it's still no match with AAC 256kbps on iTunes store ?? I'm confused

Any background information to explain are appreciated

 

[NA Blur]

I think the recording source is a CD in most cases unless someone knows otherwise so any encoding introduces loss.  Anytime you see a decrease in the bit rate you have loss.  Whether it is audible will be a test for your ears.
 
What I have noticed with purchased music from iTunes vs ripping music via iTunes is that iTunes tends add artifacts into the music.  This was not always the case with iTunes and if I remember correctly 4 versions ago there were no issues ripping music from a CD to a say 256kbps mp3.  Now it is very difficult to rip music from a CD via iTunes without finding 10% or more of the tracks with horrible artifacts.  This creates the tedious need to re-rip music one track at a time to get the perfect rip which is really impractical for large libraries of music.
 
The only thing I suggest is do a listening test and see if you can hear differences between the two types of encoding / compression.  If you cannot hear the difference go with the less expensive and more convenient method.
 
I will admit that the samples seem to have better sound quality than the downloads.  I often sample a track, then after downloading it, ask if it is the same song.  I am not sure what is going on there, but if anyone else out there has some input please share it here with us.

 

[chewy4]

Quote:

 Anytime you see a decrease in the bit rate you have loss.  Whether it is audible will be a test for your ears.
 

I don't mean to nitpick but I find in necessary since a lot of people equate bitrate with quality with no exceptions - but this only applies to lossy compression. If it's uncompressed or compressed with lossless compression, bitrate is the last thing you should be looking at. There's no need to look at it at all.
 
As for the original question - iTunes files are very likely as much from the source as a CD. They're 16 bit/44.1kHz, no? Then why would they use a different version for another format that is also 16 bit/44.1kHz? So the iTunes files are technically of worse quality, since they have undergone lossy compression.
 
For more accurate ripping you should use EAC. Some people have had good success with iTunes ripper, but it's not always flawless.

 

[warnbroom]

You might be right about the recording sources here, although as much as I read about this, the recording sources are final mastered unit of the song to be sent to Apple by artists and as they require and encoded specifically for end-devices with supreme audio quality...which is unlike those being sold on amazon and other online stores are almost 100% MP3 ripped straight from CDs. (just what I've read).

Ultimately, what led me to think of this is because lately I've examined spectrum of 2 songs, they're both the same but one is ripped from CD, other is purchased on iTunes...the results show how absurdly the frequency of ripped version is shrunk down to below the point of an AAC music file I normally seen, much lower than the version purchased on iTunes on both density and margin. Recalling that I have ripped WAV to AAC several times with iTunes, this's the first time it ever went down that much to catch my attention and keep me wondering.

Assuming Apple does rip and sell their music from CD, then what comes down to argument is what's the difference between "ripped by Apple" and "ripped with iTunes"...subject to the encoding software, hardware, compressor...etc ??

 

[warnbroom]

Thanks, will give EAC a try ...but will it make much difference when ripping WAV to AAC with iTunes than CD to AAC with iTunes ?? I assume not ?

 

[chewy4]

Quote:

You might be right about the recording sources here, although as much as I read about this, the recording sources are final mastered unit of the song to be sent to Apple by artists and as they require and encoded specifically for end-devices with supreme audio quality...which is unlike those being sold on amazon and other online stores are almost 100% MP3 ripped straight from CDs. (just what I've read).

Ultimately, what led me to think of this is because lately I've examined spectrum of 2 songs, they're both the same but one is ripped from CD, other is purchased on iTunes...the results show how absurdly the frequency of ripped version is shrunk down to below the point of an AAC music file I normally seen, much lower than the version purchased on iTunes on both density and margin. Recalling that I have ripped WAV to AAC several times with iTunes, this's the first time it ever went down that much to catch my attention and keep me wondering.

Assuming Apple does rip and sell their music from CD, then what comes down to argument is what's the difference between "ripped by Apple" and "ripped with iTunes"...subject to the encoding software, hardware, compressor...etc ??

Well Apple doesn't rip their stuff from CD, they just use whatever files the artist sends them.
 
So it is definitely possible that the artist would send them something different than what is on CD, I just wouldn't understand their logic in doing so.
 
From what I've seen AAC doesn't use a hard lowpass filter until about 128kbps, how low did the one you ripped appear to be? IIRC it should look like it's only around 18kHz at most, but then again I use the Nero encoder rather than iTunes. The type of encoder you can use can make a difference as well.
 
EDIT:
 
 
Quote:

Thanks, will give EAC a try

...but will it make much difference when ripping WAV to AAC with iTunes than CD to AAC with iTunes ?? I assume not ?

 
It could, it's all about preventing errors. EAC, dbpoweramp, and some other ripping software check for errors while I don't believe iTunes does. EAC is really slow though FYI.

 

[warnbroom]

Well Apple doesn't rip their stuff from CD, they just use whatever files the artist sends them.

So it is definitely possible that the artist would send them something different than what is on CD, I just wouldn't understand their logic in doing so.

From what I've seen AAC doesn't use a hard lowpass filter until about 128kbps, how low did the one you ripped appear to be? IIRC it should look like it's only around 18kHz at most, but then again I use the Nero encoder rather than iTunes. The type of encoder you can use can make a difference as well.

EDIT:



It could, it's all about preventing errors. EAC, dbpoweramp, and some other ripping software check for errors while I don't believe iTunes does. EAC is really slow though FYI.

It looks like this (ripped at AAC 320kbps VBR)



compared to this (purchased on iTunes)



Also I don't think Nero AAC could ever out shine iTunes AAC at any point, some have claimed so..but yeah that's just me, correct me if I'm wrong and maybe what's better is all down to personal preference

 

[chewy4]

Quote:

It looks like this (ripped at AAC 320kbps VBR)



compared to this (purchased on iTunes)



Also I don't think Nero AAC could ever out shine iTunes AAC at any point, some have claimed so..but yeah that's just me, correct me if I'm wrong and maybe what's better is all down to personal preference

Yeah it's hard to say which is better, but I just used nero for testing since that's what you can use with dbpoweramp.
 
They must be using different parameters than you. That might mean that it's technically better, but it could also mean the opposite. Remember that those high frequencies aren't even audible for most adults, especially not amongst other sounds in music, so IMO it's a good idea to throw them out with lossy compression. 
 
Your file does look like it cuts off more than a 320kbps AAC file should though, it looks closer to 256kbps.

 

[JRUNCK]

I know an artist that has his music for sale on iTunes and he didn't send in the original sources for his music it's copies. Of course not all music on iTunes is copies but some of it is. It depends on the artist who give Apple their music on what the actual quality is. This goes for Bandcamp and any other digital music source. It's very common now days for reissued CDs or Vinyl to be copies of the first press as well especially the ones that say REMASTERED. A lot of the time they are remastered to make the copy sound better but in reality the original sounds better than the "Remastered" version. So quality depends on what CD you are ripping also. The first press almost always sounds better than a reissue or repress.
 
The best way to rip your music from CD isn't using iTunes. iTunes is a quick and easy way to do it but like with anything else you get what you put into it. Exact Audio Copy does a much more precise job at ripping music in audiophile quality. It will check for errors, correct errors and provide output showing you just how accurate of a rip you truely get from each CD.
 
Here's a tutorial for properly ripping CDs using EAC in FLAC for anyone interested. Trust me it's worth learning how to use this opposed to using iTunes.
 
http://filesharefreak.com/tutorials/properly-ripping-to-flac-with-eac-099

 

[bikefixe]

I listen to a wide variety of music. For some of it I'm not sure I could discern the difference between these file types. But at 256 AAC vs 320, I could hear a clear difference with classical works that feature solo piano. My own CD rips at 256 gave a warbling sound to extended piano tones - I heard it on several recordings. When I re-ripped at 320 constant bitrate, I got the sound I expected (better.) That makes me a little suspicious of 256 bitrate stuff I get from iTunes on music where it matters to me...

 

[JRUNCK]

I perfer a high quality VBR rip over a straight 320kbps rip any day. For some reason a lot of people think 320kbps is the standard for a HQ mp3 rip but it's not as accurate as VBR. If the rip is done properly using an updated external incoder like "Lame" then VBR is better but some VBR rips are done incorrectly and will have a low average kbps of around 192kbps.

 

[bigshot]

I find that AAC 256 VBR AAC is as good as 320 CBR AAC as well, and the 256 VBR file is better optimized.

 

[JRUNCK]

I don't know that much about AAC but from what I can tell so far it's just Apples way of trapping people into buying their music format. I like Apple products but hate some of the way they do things. From what I can tell AAC is like Apples version of VBR (Standard format) and ALAC is Apples version of FLAC (Standard format).

 

[bikefixe]

I assumed, perhaps incorrectly, that VBR = variable bit rate, and that if you rip at 256 VBR, 256 is the max bitrate, and for sections of lower complexity in the music, the actual bitrate will be lower than that max. Anyone care to confirm or educate me?

 

[JRUNCK]

I don't fully understand the concept but I think what you said is correct with 256 VBR being the highest setting when ripping an album using EAC at least. But when using the latest Lame encoder the files will actually play higher than 256. If you watch the KBPS in Winamp as you play the file you will see it go up to as high as 320kbps.