audio related problem (2) pipewire/wireplumber with usb DAC

 Ubuntu 26.04 用 pipewire/wireplumber  for audio, 那以前為了 usb speaker MM-1 音量問題設的
/etc/pulse/default.pa
load-module module-udev-detect ignore_dB=1

要怎麼改? google / try error -> result

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add in /usr/share/wireplumber/wireplumber.conf.d/alsa-vm.conf

  {  matches = [ { device.name = "alsa_card.usb-Bowers___Wilkins_MM-1_304-00"  }  ]
     actions = { update-props = { api.alsa.ignore-dB = true }  }  },

  {  matches = [  { node.name = "~bluez_output.*" } ]
     actions = { update-props = { api.alsa.ignore-dB = false } }  },

第一段是呼應以前的 ignore_dB=1, 然而， 明明 device.name 都寫明了， 還是會影響到 bluetooth speaker, 加了第二段就 OK，很怪， 但有用就好

#device name 是用 pactl list short cards 得來的

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另外，usb speaker 有時會破音和奇怪的噪音，google 來修改

/usr/share/pipewire/pipewire.conf

default.clock.allowed-rates = [ 44100 48000 ]

好像有用?