1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.

    Dismiss Notice


Discussion in 'Sound Science' started by jonasras, Mar 5, 2013.
1 2 3 4 5 6 7 8
10 11 12 13
  1. kraken2109
    Maybe the tracks weren't level matched?
  2. ramachandra

    I want to check that, but i do not know any program with support for both.
    Meanwhile i have tried Ubuntu studio without installing it or change any of the setting other than turn on the S/PDIF, and asked my relative to convert FLAC to ALAC on his computer and try different players, and i have asked one of my friend to do a comparison too on his PC. Same result.
    I think only the quality of the sound source+headphones are the key to experience the possible audible difference between the two formats.
  3. nick_charles Contributor
    You are proceeding from the assumption that there should be a subtle difference that is hard to hear and only uncovered by "revealing" kit. The problem is that there should not be a difference. The puzzlement is that there is a difference between two should be identical decoded PCM streams which hints at something screwy going on somewhere, not disputing your results at all.
    My take on it is that computers are less predictable than they should be, which I know is nonsense but I mean that some specific combination of factors (which we may not be fully aware of) will do strange stuff and appear unpredictable. In the past my laptop would not find the wireless access point until I turned my wireless printer on, same with the Blu ray player and this happened many times..
    The other day my DVD drive stopped being recognized by my computer, I tried all the standard fixes  but it was just not seen by windows, or by the device manager at all. I disabled the drivers, updated the drivers, rebooted several times, used the manufacturer diagnostic toolbox - no drive detected. I booted into the bios setup did nothing but the DVD was now seen , I changed nothing came out and it has worked happily since, I have no explanation for this.
  4. rjw915
    The fact you say only Apple products will play ALAC is not true. All of the Hi-Res Players out now will play ALL formats. My iBasso and FiiO both play all formats (ALAC included). The Astell & Kern , Hifiman and PONY will also play all formats.
  5. Roseval
    As our playback chain is rather complex it is always possible that somewhere some DSP is going on.
    One option is to convert both the FLAC and the ALAC to WAV and do a binary comparison on the audio part (tags might be different).
    In general this type of test yield zero differences.
    If there are zero differences at bit level, we have the intriguing question how the same bits can sound different depending on the file format.
    The only explanation I can conjecture up is that decoding ALAC and FLAC yield different electronical noise patterns. Say one a bit more I/O, the other a bit more CPU or one a more steady processor activity and the other a more burst like pattern, etc.
    Then we have to assume that this noise creeps into the DAC en modulates the analog out in some way.
    Sounds a bit farfetched maybe but there are measurements demonstrating the difference between an isolated DAC and a non-isolated DAC e.g. by using a USB-isolator: http://www.thewelltemperedcomputer.com/Intro/SQ/GalvanicIsolation.htm
    So the bits might be identical, the way they are prepared differs.
    If this true, an interesting experiment would be to use a media player supporting memory playback.
    All I/O and all decoding are done on the entire track en stored in memory before playback starts.
    This should eliminate all differences due to the “preparation” of the bits.
  6. old tech

    Correct, both my Naim NDX and Bluesound streamers play ALAC files.
  7. watchnerd
    Confirmation bias. Placebo effect.  Look them up.
  8. castleofargh Contributor

    we can't totally exclude the possibility of them sounding different in very poor situations. could be a problem with the computer resources, full of bugs/viruses/etc, maybe not enough RAM राम
    I compete for lamest pun 2016 and will now go hide, full of shame.
  9. ramachandra
    First when i experienced difference between formats was years ago with a modified SB Xtrememusic card. I was disappointed when the tracks in FLAC format had inferior dynamic compared what was on YouTube. In those days i speculated it has to do something with mixing or maybe the video based on a higher quality master file. Yet it was still strange because i read somewhere the YouTube videos stuck around 128kbps bitrate, and FLAC files go well beyond that. I have not done any more research on the subject in those days.
    Since my PC hardware completely changed, years gone, and i have used couple of different virus scanners. I show a tendency to no pay for them just keep them until the 30 days trials is up, then move to the next and after couple of months restore the whole system from a clean backup (not the windows system restore). Then start over again. I have a desktop built for gaming, it has 16GB RAM, AMD FX8350 Processor, etc. the operating system is Win7 64bit. The other two desktop PC i have mentioned above based on Intel CPUs and capable gaming rigs too. So the the computers performance and virus scanners is not not holding back, and we do not really run other than Skype in the background or let the PC flooded with rubbish.
    My audio chain during the test was SB Titanium HD => optical to coax adapter => parallel Wolfson WM8740 DIY DAC => Beyerdynamic DT990Pro headphones.
    The other two PC have modified SB Titanium cards and both have a modified Logitech Z5500. I have started threads about them, the information to reproduce the environment is easy if you wish.
    I'm giving this details because you do not know what kind of hardware was involved, neither i what other people are using, and we all can be right under the circumstances, still not benefit from the informations.
  10. coli
    If you notice audible differences from different lossless format and you are sure they are bit identical, then you need a  better, properly implemented DAC. Been there done that.
  11. castleofargh Contributor

    wouldn't the dac receive the same basic PCM format in any case? I would imagine a difference (if it exists) coming from badly done conversion when creating one of the files, or the player software/computer to create a particular problem when extracting one of the files. or our usual best seller, people mistaking 2 masters for the same song.
    but I don't see why the DAC would play any role in this?
  12. coli
    Jitter differences. Some very expensive "audiophile" DAC can't handle them, while any cheap mass market DAC will.
  13. ralphp@optonline

    On the other hand perhaps all DACs handle jitter just fine and since humans can't process sounds in the nano and pico second range it's only the audiophiles who claim that jitter is a problem. And with "problems" come "solutions" $$$$$$$$$$$$$$$$$$$$$$
  14. ramachandra
    We have done lot of this and that, been in here and there. From details we may learn something.

    You recommend better properly implemented DAC. OK, but how is that in logic with "any cheap mass market DAC"? For a millionaire a 1000$ DAC is cheap. If I'm thinking about the bottom price USB pendrive size i doubt it.
    The DIY DACs I have cost around 150€ the SB cards even less, of course it is only the price of the components, i do the soldering, installation.
    "perhaps all DACs handle jitter just fine" Just change the receiver chip's clock on a USB DAC to a 20$ ultra precision for example. You will be an audiophile that day if not already, just not aware of the definition. Otherwise i do not understand why anybody interested about a thread like this. [​IMG] 
  15. hogger129
    I have never heard any difference between ALAC and FLAC.  My library is all FLAC and then I transcode to whatever lossy format I need for listening.
1 2 3 4 5 6 7 8
10 11 12 13

Share This Page