If those of you who think that Apple lossless and wav files sound different I would suggest the following - rip the wav file with one ripper and the Apple lossless with iTunes. Then convert the Apple lossless to wav and compare the files bit for bit - EAC and foobar both have facilities for doing this. If you use EAC for the wav file you need to account for the disk offset that EAC uses. When I have tried this I find that the files are bit for bit identical. Note - EAC wav files may be different if they are ripped from a damaged disk, but from a clean disk the 2 processes will produce the same bits.
I believe it is possible to still hear differences from different formats but it will be because of some other issue in the playback chain, not the bits in the file. For example, a wav file played with foobar and an Apple lossless file played with iTunes may differ based on how the 2 players deal with the audio subsystem - for example using ASIO to bypass KMixer with foobar but going through KMixer with iTunes. With the Wadia those differences should not be as important.
It is pretty easy to convert from one lossless format to another, so once you have ripped your library you should be able to change to other formats as you wish. Tagging is the main issue then, but that can be handled for a few hundred CDs. Many think EAC is the best ripper, although it can be slower than others. I found that EAC and iTunes produced the same files for the CDs I compared, but they were in pretty good shape.
I would suggest doing lots of experiments with a few CDs you know really well. Figure out what works best for you then do the rest of the CDs. Once you have a good rip in any lossless format you should never have to rip again. |
Peter_s and Steve - I would like to understand just what extra information is in an ALAC file that degrades its sound. Any explanation or references to this? I know that this is a proprietary format, but if the claim is that there is some extra data in it, it would be great to have some idea or what that is and how it is used. References?
Jax2 - I am not a MAC user, sorry. But EAC and foobar both have comparison routines in them for wave files. Do I read your post correctly that you are using a MAC to stream to a Transporter? The Transporter is yet another wrinkle in the comparison - not sure exactly what it uses for ALAC decoding.
I really think that concluding that iTunes is inferior for ripping files (at least from relatively clean disk) based on these observations is premature. I, and others, have ripped files with iTunes, converted them to wave and they are EXACTLY identical to wave files produced from EAC - every bit is the same. And a 50 MB wave file has a lot of bits! Two wave files with exactly the same bits cannot sound different when played by the same player. If somehow they do sound different, then something else has happened in the process. I just do not see how iTunes ripping can be inferior when it produces exactly the the WAVE file as EAC? Incidently, I do believe that EAC can do a better job on a damaged disk - but of course none of us has those :)
If a given player playing an ALAC file and playing a WAVE file produce different sounds, it is a big leap to believe that the only cause of this could be the ripping process. It may well be how the player somehow handles the different formats.
My background is scientific research and in computer science. So, when I hear that there are differences in 2 approaches I want to know why. And I tend to get picky about experimental design. In looking at the results that people are reporting I see lots of unaccounted for variables. The experiments need to be designed to eliminate those variables. My suggestions, although it will take time, is to
1) Compare the sound of ALAC files ripped with iTunes (using the error correction mode) and ALAC files that were ripped to WAVE by EAC and converted to ALAC by iTunes - both played with iTunes (or your favorate player). If you are using something other than iTunes, you should probably use the same conversion software as your player uses. It is hard to do bit compares on these ALAC files, unfortunately. Waves are much easier.
2) Compare the sound of WAVE files ripped with iTunes (directly to WAVE) and WAVE files ripped with EAC. This should probably be done with iTunes as well as with some other player like foobar or J River. Foobar is a good choice since it has a ABX comparison function to allow for blind testing. When I have done the ABX comparisons with foobar with EAC and iTunes produced wave files, I cannot reliably tell the differences - although I admit I have not done it a lot of times and blinding test is an art unto itself. If you have not done it, give it a try. It is a interesting experiment.
3) Repeat 2) with files ripped with iTunes into ALAC and then converted to WAVE by iTunes (rather than ripped to WAVE directly).
Its important to compare apples and oranges and to be sure to eliminate outside influences on what is being tested - in this case ripping accuracy.
Now off to listen to some music.
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Interesting observations.
Sidssp - Did you try ripping the tracks that sounded different on the burned CDs and comparing them to each other and to the original ripped tracks? It would be interesting to see if the bits are different. If so, then the burning process may be the issue - which I think is what I think you concluded.
Peter_S What do you think caused the differences you hear? Do you agree if the bits are the same, the files should sound the same? If so, you might want to compare the actual files bit by bit. It is certainly possible that there is some error in the conversion process. You could compare the Apple lossless files with a file compare utility like fc/b, although it is pretty crude. You can also convert the Apple lossless to wav and compare those files using EAC or foobar. As I said above, when I ripped tracks to Apple lossless with iTunes and converted them to wav and compared to EAC ripped tracks, they were identical. Have not tried a bit compare after doing a wav to Apple lossless conversion but could try it. Also you could convert the Apple lossless lossless file that was converted from the EAC wav file back to wav and compare it to the original EAC wav file to see if the round trip introduced differences. EAC has a good comparison routine, although you have to set the disk offsets to 0 when ripping with EAC to do the comparison. Another interesting thing to do is to take the EAC wav and a iTunes ripped Apple lossless file converted to wav and use the ABX facility in foobar to do a blind test of the two files. Much harder to do comparisons with iTunes. (I don't want to get into a discussion of blinding testing - just wanted to point out the utility in foobar.) |
Steve - I do not believe a 24-bit file and a 16-bit file would compare exactly. The extra 8 bits per sample have to be stored somewhere. So I am not sure what you mean by this.
Can someone do a bit compare on the Apple lossless files and see how different they are? As a first pass, do they contain the same number of bytes? (Although you have to be aware of the how the offset is set in EAC and how silence between tracks is handled.)
If there is a difference, then it could be either in the iTunes ripping process or in the wav to Apple lossless conversion. In fact, if a Apple lossless file ripped by iTunes is converted to wav and becomes identical to an EAC wav file, I would conjecture that the iTunes rip was as good as the EAC rip. If you take the iTunes ripped file, oonvert it to wav with iTunes and then convert it back to Apple lossless does it sound different than the original file? Does it bit compare?
Not trying to be difficult. I just want to figure out if the data in these files are different and if so where the difference comes from. |
The process that Apple lossless uses to "compress" the file reduces the file size but not not delete any data. Think of it like a ZIP file, which reduces the size of a file but when upzipped the data is exactly the same as you started. Apples lossless and flac do a similar process. There are well known algorithms for doing this type of "compression". They look for patterns that they can store in less space. So the "compression" uses less space but maintains all the original data. When the file is played back, the file is "de-compressed" to its orignal form. The earlier discussion in this thread is about possible subtle differences in Apple lossless encoding, but that is a different issue that the 50% difference in file size.
My copy of Pop Pop arrives today and I will doing some listening this weekend. |
Jax2 - I have been wanting to get Pop Pop for a while so this seemed like a good time. A lot of the music I listen to (50s/60s jazz and female jazz vocalist) often does not have great sound stage, so I thought I would eliminate that variable and go with what you were using. I recently did a comparison of my PC with a McIntosh 301 CD with top end McIntosh equipment - MDA 1000 DAC, pre, tube power and speakers. Used 301 as a transport so both player and PC went through the DAC. On a lot of my music there was little difference between my PC and the McIntosh 301. However my dealer pulled out some of his favorite test tracks and then we cound definitely hear a soundstage difference. My PC was more forward and a little more detailed that the McIntosh CD player. I liked the PC, he liked the McIntosh. The differences were comparable to listening to CD players from different vendors.
I did try comparing the bits of some EAC rips converted to Apple lossless and then back to wave. Using EAC to compare the original and the twice converted file EAC reported no differences in the files. Also tried several tracks ripped with iTunes to Apple lossless and then converted to wave by iTunes. Again, EAC compare showed they were the same as the EAC ripped track. Next step is some detailed listening which I hope to do this weekend.
Does anyone know of a free ftp server site that allows people to exchange large files? There used to be ones that you could just access through a browser without having to set up server software, but I have not used one in a while. That would make trying different files easier. |
Pop Pop is a fun CD. Still need to do some critical listening. I was aware of the Norma Winstone CD since it was nominated for a Grammy, along with Karrin Allyson's Imagina and Stacey Kent's Breakfast on the Morning Train, two vocalists that I really like. I will have to get a copy of Distances. ECM always does a great job on their CDs. |
Last night, I finally got to compare ALAC files ripped with EAC and iTunes - used test and copy to generate the EAC wave files and used error correction with iTunes (V 8.0.2.20). I used iTunes to convert wave to ALAC. My wife(she has better ears than I) and I separately compared several tracks playing through iTunes, including Bye Bye Blackbird from Pop Pop. We both originally thought we could hear differences but in the end neither of us could reliably identify differences. If there were differences they were too subtle to identify reliably. Interesting, the differences we both originally thought we heard were not with soundstage but with the amount of air around notes and the attack in the treble. Unfortunately, iTunes does not have an ABX comparison routine which is very useful for finding subtle differences. I also played the same tracks through my CD player (output to the same DAC) and compared them to iTunes and again any differences were too small to identify reliably.
I also tried comparing the same tracks through J River Media Center 13 using flac files. I thought the J River was a little more dynamic but it is hard to compare different players in real time. Any differences with iTunes and J River were small at most, but I need to do more work on that.
My system is not overly detailed - it is set up as a smooth more "musical" system. Classe CP-65 pre, Levinson 432 amp, Sonus Faber Cremona speakers with Transparent Ultra cables. CD is Classe CDP 10 and DAC is Musical Fidelity A3.24. My USB to optical converter is a Turtle Beach, which is the weakest link in the system. I am sure the jitter will come up, but it does sound very similar to my Classe CD player, so I do not think it is hurting very much. Also, I did prefer my PC source to a McIntosh MC301 CD player (in an all McIntosh system), which is a pretty good player. I will probably replace the USB converter with a 24/192 one in the future - probably using J River.
Moving to J River will mean I probably will start using EAC so it is easier to generate flac files. But I see no reason to re-rip my existing libary at this point.
I would be happy to post my Bye Bye Blackbird files to a ftp server (if I can find a reliable one) if anyone would like to try my files. |
Jax2 - Have you compared the same tracks from a CD player to the same DAC you are using for iTunes? I found that on my system, there is little difference. Once I got to the state of being as good as my CD player, I have sort of stopped until I can try a setup that plays 24/192 material.
Unfortunately, on the Grammy show they play stuff I am not interested in listening to. Not sure if they ever played any of the jazz on the show - only got through about 20 minutes before turning it off. |
