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DAC8x channels swapped after startup

Stephan Brenner

June 03, 2025 07:39

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Hello,

currently I'm using a HiFiBerry DAC8x + RPI5 + CamillaDSP for my 4 way active speaker project. This combination works like a dream, great possibilities with minimum effort. But I have a serious problem which I cannot figure out and other posts didn't give me any answer.

Occasionally the output channels get swapped after startup. This means for example that the subwoofer output is connected to the tweeter amplifier. Nothing was changed in the hardware of course. Thats not great for the speakers. As far as I could figure out, this is not a CamillaDSP problem. The filters and so on are still mapped to the prior channels 0 to 7 of the DAC8x. For me it seems that Raspbian mixes up the hardware port and the software channel number. After a restart everything is fine again.

Does anyone have an idea how to prevent this? Is there a possibility to fix the routing of the channels in the raspbian soundserver?
Many thanks in advance.

 

Stephan

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6 comments

• 0
  
  HiFiBerry team June 04, 2025 16:30

  Sounds strange. We haven't seen this before. When you're talking about the soundserver - do you mean Pipewire?

• 0
  
  Stephan Brenner June 04, 2025 16:41

  es with "soundserver" I meant the default sound system in Raspian. I do not know whether this is Pipewire or Pulseaudio.

  I recognized one difference to the CamillaDSP config done by other. I used 24LE as dataformat, 32LE seems to be more appropriate. But I'm not sure whether this changes something. Strang, in deed.

   

• 0
  
  HiFiBerry team June 04, 2025 16:44

  S24LE is a format we always recommend to avoid. As it is not aligned with the underlaying architecture, it's really hard to process.

  Also check if you're using the native hardware device or some sound server like Pipewire (which is the default in a "full" Raspberry Pi OS)

• 0
  
  Stephan Brenner June 04, 2025 16:52

  thanks a lot. I did not know this.
  The device I use is quite simple: hw:sndrpihifiberry. This seems to correspond to other users.

  By the way: is there an improvement in sound quality when switching to the studio DAC8x or is the only difference the fully differential output?

• 0
  
  HiFiBerry team June 05, 2025 05:20

  Try using S32LE. We have seen some bugs with S24LE in the past, even though we haven't heard anything on the Pi5 yet.
  
  Sound quality in terms of noise and distortions of the DAC8x and StudioDAC8x is very similar. If you don't need balanced outputs, stay with the DAC8x.

• 0
  
  Phil Anderson June 05, 2025 13:43

  We were having a few issues with the DAC8x. Sometimes channels would swap and other times on boot there would be no sound at all, just hum.  We disconnect audio to load different soundfonts and it would also swap channels after connections were made. There might be an issue with pipewire making/breaking connections to ports.

  After many hours of troubleshooting, we decided to remove pipewire and go back to using Jack with qjackctl. Everything seems stable now.