# Playing the audio through your Loopback interface makes it possible to capture it, # but there will be no sound in your speakers. In order to play audio on the loopback # interface and your actual interface you must make use of the ALSA multi channel. # See https://github.com/karlstav/cava pcm.!default { type plug # <-- no { here slave.pcm { type multi slaves { a { channels 2 pcm "hw:0,0" } # the real device b { channels 2 pcm "hw:Loopback,0" } # the loopback driver } bindings { 0 { slave a channel 0 } 1 { slave a channel 1 } 2 { slave b channel 0 } 3 { slave b channel 1 } } } ttable [ [ 1 0 1 0 ] # left -> a.left, b.left [ 0 1 0 1 ] # right -> a.right, b.right ] }