AAC low volume playback usb

Answered
John Reynolds
A few of my downloaded iTunes songs which includes albums too have considerable lower volume than the others I’ve downloaded. I have to be careful when turning up the volume on these as the next good one would be deafening. I have no issues playing these in the car usb or through Bluetooth on iPhone just on the Node 2i. I did a conversion in iTunes from an affected AAC to MP3 and that worked and plays at the correct sound level!
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Comments

13 comments

Date Votes
  • Official comment
    Tony W.
    Product Support Manager

    Thanks for your patience. Some time back, BluOS Engineers noticed a problem with AAC decoding they were able to resolve by adding a switch during decode and reported it back to GPL. It looks like about a year ago, the Open Source Community resolved that bug and our switch no longer resolves the issue but exasperates it. After retesting, BluOS Engineers are removing the switch in the next major release of BluOS. I do not have an exact time frame on this, but we expect mid-May (2024).

    Thanks for the sample content Adrian - it was very helpful in identifying the exact root cause...

  • Bjørn Ulvik
    Hi-Res
    • Edited

    Could be expected if Replay-gain is turned on in audio settings.
    There's no need to convert/recode, just turn off Replay-gain, or use any tag editor and remove the tags;

    replaygain_album_gain and replaygain_track_gain

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  • John Reynolds

    I’ve tried all these gain settings and still no good. Don’t know much about the tag editor bit but why have to go through this?
    Thanks anyway Bjorn

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  • John Reynolds

    Last one I downloaded with low volume was
    Paipy and Sarah Russell ‘What Do I Do’
    Quite appropriate I thought. If I could get one of the support crew to download that and see if it works for them at the normal volume then I know my machine is the problem. I have reset numerous times too just in case anyone asks.

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  • Björn Gunnarsson
    • Edited

    This has been the case for some time when playing specific AAC files on my Node 2i as well. I suspect the problem is the way Node 2i decodes some AAC files, might be related to how the files have been encoded since it’s not affecting all files/albums downloaded from Apple. Enabling or disabling Node 2i ReplayGain does not help. Enabling or disabling Node 2i fixed output level does not help.
    Recent issue:
    Jacob Collier’s latest album Djesse vol. 4, purchased and downloaded from Apple as AAC files, saved on network share and indexed by Node 2i.
    All songs on the album played through Node 2i has low output volume.
    Skipping within a song (using BluOS app) makes the output volume increase for a second (to a level that would be excpected and considered normal) but then falls back to low volume again. Almost as if Node 2i was altering gain based on ReplayGain information although it has been disabled in the player.
    For comparison, Michael McDonald’s album Motown Two downloaded from Apple as AAC files does not have this issue when played back on Node 2i, output volume is consistent and normal throughout.

    Example albums played back by Node 2i at low volume (AAC files):
    - Djesse Vol. 4 by Jacob Collier https://music.apple.com/album/djesse-vol-4/1725446442
    - Heroes (& Instrumentals) by The Midnight https://music.apple.com/album/heroes-instrumentals/1649037958

    Example albums played back by Node 2i at normal volume (AAC files):
    - Motown Two by Michael McDonald https://music.apple.com/album/motown-two/1440788624
    - Then Again by mitch murder https://music.apple.com/album/then-again/1560760405

    Would appreciate if support would look into it.

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  • Björn Gunnarsson

    With ReplayGain disabled in the player I would expect the volume of the files in my examples to play back at consistent volume. The skipping issue described makes me think that the issue is player related. No volume issues when playing back the files using other applications (File Explorer Pro, Cog, Apple Music). And I have not had any output volume issues with my FLAC or MP3 files, it’s only affecting some M4A files (albums purchased and downloaded from Apple iTunes/Apple Music).

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  • John Reynolds

    Yes, seems to be the same issues I have Bjorn thanks for replying.

    No issues with my cd conversions to AIFF files. In the meantime I'm having to convert Itunes downloaded AAC to MP3 which isn't good.

    If I recall once or twice just touching the volume slider put the volume back up to the correct level just for a second only though. 

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  • John Reynolds

    I tried the new Node and that was the same. Sorry forgot that bit.

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  • Björn Gunnarsson
    • Edited

    I performed an A/B test with an iTunes album that has the low volume playback issue on my Node 2i (Wide Open by Michael McDonald):
    - Duplicated all album M4A files.
    - Removed all tag info from the duplicates (including all ITUN tags) using MP3 Tag.
    - Let Node 2i reindex collection.
    - Played song from original album and duplicate album but the issue is the same for both original and duplicate; low volume at playback that temporarily is raised when skipping within a song.

    I’m clueless what causes the output volume to be low when played back by the Node2i. Since tags are removed it does not seem to be tag related.

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  • John Reynolds

    Like I said in the mean time I'm converting AAC to Mp3 which isn't ideal.

    If I miss a conversion there's a chance it could blow a speaker and they are my new Dynaudio Emit 10's

     

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  • AdrianW
    • Edited

    John, i've just ran into this issue myself. I just got a Cyrus Classic Stream which uses the BluOS platform. Any iTunes purchased album in Apple Lossless AAC from about 2022 onwards is effected. It needed to be a new album release from 2022 onwards. I get the same low volume problem you are experiencing. Also this isn't just on USB. Its on your local music drives as well. Synology NAS in my case. 

    I'm amazed more people are not moaning about it. 

    The issue appears to be the way Apple or the tools the music company is using to encode the Apple lossless file and BluOS cannot play the file back correctly.

    None of my other streamers exhibit this issue ... Sonos, Sony walkman, Car ... etc.

    This issue has nothing to do with gain settings. The volume playing these tracks isn't just slightly different. Its very different to the point where you can hardly hear the track playing. 

    The only workaround is you can convert the file to either Mp3 or re-encode it to Apple Lossless AAC again. This seems to fix the volume issue, but its not ideal. Not sure what re-encoding a file really does and its a PITA. 

    So hopefully BluOS support can look into the issue? 

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  • Tony W.
    Product Support Manager

    DUPLICATE IN LINE POST

    Thanks for your patience. Some time back, BluOS Engineers noticed a problem with AAC decoding they were able to resolve by adding a switch during decode and reported it back to GPL. It looks like about a year ago, the Open Source Community resolved that bug and our switch no longer resolves the issue but exasperates it. After retesting, BluOS Engineers are removing the switch in the next major release of BluOS. I do not have an exact time frame on this, but we expect mid-May (2024).

    Thanks for the sample content Adrian - it was very helpful in identifying the exact root cause...

    0
  • John Reynolds

    Thats good news Tony thanks,  looking forward to it.

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