[r010159]

  How about you try the same test with the same person using a flac or AAC lossless file, or even an uncompressed wav file for that matter.  In other words don't let the player make any decisions about the audio if possible.  It would be interesting to see if the musician who obviously has good ears can distinguish the players then.  It would be instructive to me too since I would finally know if the difference I was hearing was the codec as opposed to the 'bit perfectness'.  I am hoping at least they cannot distinguish as it would make the whole thing easier for me to come to terms with mentally.  I mean if they do sound different then you really do start wondering what 'bit perfect' even means.
 
[snip]
 
Could be that advertising bit-perfect isn't the real discriminator between a good player and a lesser one.

 
I have run some tests with the guitarist. The first test was with the same player, J River. The compressed audio files sounded cold, sterile, and "digital" to her. The ALACs (FLACs) sounded much warmer but still had the same detail. I think when uncompressing lossy audio files, there are allot of "blanks" to be filled in by the software to provide a complete sonic picture. I tried to pick similar tracks from different albums.
 
The second test was between two players, Audirvana+ and J River.  This was done with compressed AAC files. J River appears to be more accurate to her, particularly with the high frequencies. She called the J River player "awesome". It looks like some software fills in the "blanks" better than other software.
 
Interesting test results, don't you think? 
 
I thought the only difference there can be is where one is more bit-perfect than the other. But you have pointed out this is not the case with compressed files.
 
Bob Graham

 

[brhfl]

   
[…]
 
I thought the only difference there can be is where one is more bit-perfect than the other. But you have pointed out this is not the case with compressed files.
 
Bob Graham

Lossy files (MP3, AAC, Vorbis) are, by definition not bit-perfect. That's (to oversimplify) the loss. Losslessly compressed files (FLAC, ALAC, Shorten, APE) are compressed, but discard no information. They are, by definition, bit-perfect. Of course, something else in the chain could modify the bits before they get to the DAC, but compressing your audio in this way will get you the same bits upon decompression. Of course uncompressed audio (WAV or AIFF containers, or raw PCM data) is the same, without the compression/decompression process.

 

[r010159]

  Lossy files (MP3, AAC, Vorbis) are, by definition not bit-perfect. That's (to oversimplify) the loss. Losslessly compressed files (FLAC, ALAC, Shorten, APE) are compressed, but discard no information. They are, by definition, bit-perfect. Of course, something else in the chain could modify the bits before they get to the DAC, but compressing your audio in this way will get you the same bits upon decompression. Of course uncompressed audio (WAV or AIFF containers, or raw PCM data) is the same, without the compression/decompression process.

 
What is interesting is that she noticed a difference in two bit-perfect players with the same lossless audio file. She is sure about this. So apparent;y there is something more involved than just lossy files.  By the way, I told her there may be or may not be a difference. And I did not tell her which player I was demoing for her. She accurately picked out the J River player because off what she calls the "balance of the sound". For several testing sessions over days she has been able to pick out the J River consistently. So there is some ancillary processing going on in at least one of the players.  She still thinks the J River is the most accurate.
 
What can give a difference on sound but create very similar waveforms? An equalizer?  Or maybe a compander?
 
Bob Graham
 
PS: I always have been able to tell the difference. I just happen to like the sound signature of Audirvana, even though it is less accurate. I have limited hearing. My hearing has a significant rolloff at 12K. So I may not be able to appreciate the accuracy in the high frequencies.

 

[groovyd]

Surprising this... I would double check you truly have no additional processing turned on in either player.  Even so I can believe there may still be additional processing going on in one of them or both.  After verifying there are absolutely no DSP effects in either chain for example soft clipping, compressor, volume leveling, etc.  Might need to consult directly with the makers of the players to assure they are indeed in their all off's state.  If this still causes a predictable difference in sound then the only thing left to do is snoop the USB bus and see which one is actually delivering the bit-perfect data.
 
This is very interesting and I do hope you get to the bottom of it. Perhaps you uncovered a bug in one of the players.

 

[r010159]

OK. I will get to the bottom of this. I checked and I do have the equalizer lowering the 8K band with a very narrow impact. It calls this a "Q" of one. But I made this change from complete accuracy today, adjusting for the headphones with my poor, limited hearing. All the tests over the previous two days have proved she can tell the difference with ALAC files. This is back when I checked all the settings of both players, disabling anything that even remotely looked like it could effect the sound., basically returning each player to its default settings.
 
What are the adjustable filter parameters that the documentation of Audirvana talks about? That is the only difference that I can think of between how each player is set up. The documentation talks about things like pre-ringing and post-ringing, and adjusting the slope of the filter. It speaks of sonic tradeoffs with each setting.
 
Bob Graham
 
PS: I have just realized there is one additional parameter called "clip protection" that is on, which is its default setting. Now its on "flat line overflows". However, I looked at the ALAC with which I tested. The audio does not even come close to clipping.

 

[groovyd]

Yes, make sure you turn everything off before getting another lossless audition involved.  I would even recommend contacting JRiver and Audirvana just to make sure everything is indeed off.  These players have so many cryptic terminology and hidden menus you never know what is doing what and when.  I am sure however both of these player makers would love to make sure you have their player setup properly for such a comparison to back their 'bit-perfect' claims.  
 
Take the time to do it right and you may surprise everyone in the process as to what is really happening here.  I think this is a great experiment you are doing for the community.

 

[r010159]

  Yes, make sure you turn everything off before getting another lossless audition involved.  I would even recommend contacting JRiver and Audirvana just to make sure everything is indeed off.  These players have so many cryptic terminology and hidden menus you never know what is doing what and when.  I am sure however both of these player makers would love to make sure you have their player setup properly for such a comparison to back their 'bit-perfect' claims.  
 
Take the time to do it right and you may surprise everyone in the process as to what is really happening here.  I think this is a great experiment you are doing for the community.

 
Here is an interesting paper: http://people.xiph.org/~xiphmont/demo/neil-young.html
 
It goes into detail why sample conversion can lead to artifacts. So I will make sure there is no sample conversion happening by making sure the music is played in its native mode (sample rate). 
 
I have set up both players to their defaults, since I discovered that with both this is what produces bit-perfect playback. I have integer mode turned on for both. This is because when I turn it off with the J River MC, I get allot of static that obliterates the music. Apparently this is a bug when the player is used on my system. And I made sure that any alteration of the music when there is clipping has been turned off for both. Also only lossless audio files will be used. All tests will be of the A/B/X type.
 
I will add to this post as my efforts progress on this project.
 
Bob Graham
 
PS: It is better that I am not personally doing the listening comparisons. Besides relatively poor hearing, I am easily swayed by music that has a type of  "processed sound" to it. For instance, the Audirvana+ to me sounds like a small amount of reverb is applied to the music.

 

[groovyd]

Def sample rate conversions will change everything, no question.  Wish this test was possible without integer mode since I can't use that because it does not allows sharing your audio device with other apps like skype or web videos from safari.

 

[r010159]

This looks interesting. The guitarist now tells me they are pretty close, but still different. She said the rhythm guitar stood out more in the mix. Everything else seemed about the same. Once again she picked out J River. Right now I am going to find out what caused the difference that was more obvious in the past.  I think I know what this is even though I thought it would be more innocuous.  Still it looks like bit-perfect players may not sound the same, but they are *pretty* close in a head to head comparison when they are configured using their defaults.  Earlier I did notice a difference in waveforms in an editor, but it was small. I thought this difference may or may not be audible. But now I know the differences are audible to a small extent. I did confirm that there is a difference between higher sample rate AACs and lossless ALACs, which I also find interesting.
 
EDIT: Now I have played both players using the same compressed audio files, instead of using ALACs. Now there is that more obvious difference she noted in the past. She even noticed that some bass notes seem a little bit distorted. Once again, she picked out J River as doing a better job on playback. As a more personal note, I will say the only other difference was that the "clip protection" was enabled. I think I have noticed a difference in this myself.
 
So much for the specific differences I thought I heard.
 
Bob Graham

 

[groovyd]

I too like the sound of JRiver on my setup which already leans toward bright and JRiver is less siblant.  My guess is that has to do with a better codec for decompression of lossy material.  Also enabling the soft limiting helps I think.

 

[r010159]

  I too like the sound of JRiver on my setup which already leans toward bright and JRiver is less siblant.  My guess is that has to do with a better codec for decompression of lossy material.  Also enabling the soft limiting helps I think.

 
I enabled EQ for my headphones, effects for just a little reverb, and the output selection for the soft clipping feature. This is quite nice! I do not think my Audirvana+ will be getting much use anymore. I will not be needing upsampling and the control that the Audurvana+ provides for this feature. My Fidelia player has problems with some updates to the OS that I have installed. 
 
It is time for enjoying some music. Life is good now! 

 
Bob Graham

 

[groovyd]

I also tried a number of other player like A+ and others and always found myself fighting with their interfaces or getting drop outs or other crashes.  It wasn't until JRiver that I stopped using iTunes.

 

[r010159]

  I also tried a number of other player like A+ and others and always found myself fighting with their interfaces or getting drop outs or other crashes.  It wasn't until JRiver that I stopped using iTunes.

 
I had significant problems with their interfaces too, glitchy and even buggy. Those that interfaced with iTunes were the worst. And with Fidelia I had occasional dropouts. But I think I found one problem with J River. The currently playing song is not marked or highlighted in anyway. This is a nice feature to have on a player. Maybe it is an option that needs to be enabled?
 
BG
 
It looks like I found the solution. Only particular skins have this feature.