Adding to the subject : I found on the web and in the source code of HDSPMixer 2 interesting things, namely: - despite the effective 3x16 channels, it seems the internal channels might be 3x64, or at least 64 inputs, 64 outputs and ??? playback channels - the source code shows a "playbacks_offset = 64" variable I don't really see how to use these news as the code below doesn't work. (reminder : the goal is to connect playback channels 1&2 to outputs 7&8) function set_gain () { amixer -c hw:0 cset numid=1 $1,$2,$3 > /dev/null 2>&1 } function reset_matrix () { for out in $(seq 0 63); do for inp in $(seq 0 63); do set_gain $inp $out 0 done done } reset_matrix #following lines tried 2 by 2 : set_gain 0 6 65535 #doesn't work (I tried 0 and 1 inputs as there is sound there in graphical HDSPMixer vu-meter) set_gain 1 7 65535 #doesn't work set_gain 64 6 65535 #doesn't work (64 and 65 as 1st playback channels) set_gain 65 7 65535 #doesn't work set_gain 0 128 65535 #doesn't work set_gain 1 129 65535 #doesn't work set_gain 64 128 65535 #doesn't work set_gain 65 129 65535 #doesn't work exit 0 Any idea ? Le 28/11/2016 à 13:00, linux-audio-user-request(a)lists.linuxaudio.org a écrit :