Hi folks.

It took me while to figure it out. (Daily life under Linux).

As a matter of fact  "amixer cset numid=5 $input,$output,32768" will set the chosen route to 0db.

The Linux/Alsa documentation around the HDSP cards is unfortunately pretty "fragmented"  and HDSPmixer is not what I'd call a 100% clone of Totalmix, which doesn't make life easier,.

Anyhow. The main problem was to find a working approach with amixer. The main issue was actually to find out the right channel id's of input and output channels.

There are endless possibilities and the ones listed in the script header were not matching the ones I identified.. Therefore I wrote a simple script to check them all out.

Perhaps somebody else can make use of the script - that's why I attach it.

Have fun. Enjoy.
\Klaus

HDSPscan

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#!/bin/bash
#
# written by Klaus Schulz 10/25/2009
#
# This script scans the matrix mixer of RME HDSP  9632 for input/output connections
# Your current setting will be removed. Use the script at your own risk.
#
# RME HDSP  9632 ( as per definition)
# inputs: 0-7 (analog), 16-23 (adat), 24-25 (spdif)  26-43 (playback channels)
# output: 0-7 (analog), 16-23 (adat)  24-25 (spdif), 26-27 (line out)

track="/dev/shm/play.wav"  # will be generated by the script!!!!!!!!!
alsainterface="plughw:0,0"

inputs_left=( 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 )
inputs_right=( 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 )
let cnt_i=${#inputs_left[@]}-1

outputs_left=( 0 2 4 6 8 10 12 14 16 18 20 22 24 26 )
outputs_right=( 1 3 5 7 9 11 13 15 17 19 21 23 25 27 )
let cnt_o=${#outputs_left[@]}-1

function generate_track () {
which sox  > /dev/null 2>&1 || { echo "Please install sox first!"; exit 1 ; } ;
sox -r 44100 -b 16 -c 2 -n $track synth 2 sine 300-3300 gain -18  # gain in db
}

function init_matrix () {
    echo -n "Initializing HDSP matrix-mixer..."
    for output in $(seq 0 27); do
        for input in $(seq 0 43); do
            echo -n "."
            amixer -D hw:DSP cset numid=5 $input,$output,0 > /dev/null 2>&1
        done
    done
echo
}

function scaninputs () {
for i in  $(seq 0 $cnt_i) ; do         
          in_l=${inputs_left[$i]}
          in_r=${inputs_right[$i]}
          for y in  $(seq 0 $cnt_o) ; do
                    out_l=${outputs_left[$y]}
                    out_r=${outputs_right[$y]}
                    echo  "Connecting input:$in_l/$in_r to output: $out_l/$out_r"
                    amixer -D hw:DSP cset numid=5 $in_l,$out_l,32768 > /dev/null 2>&1
                    amixer -D hw:DSP cset numid=5 $in_r,$out_r,32768 > /dev/null 2>&1
          done
          aplay  -D$alsainterface -fcd "$track" > /dev/null 2>&1 &
          echo "Playback started..."
          echo -n "Any sound ? (y/(N)):"
          read z
         
          if [ "$z" == "y" ] ; then echo "Identified inputs: $in_l/$in_r" ;  break ; fi 
         
          for y in  $(seq 0 $cnt_o) ; do   
                    out_l=${outputs_left[$y]}
                    out_r=${outputs_right[$y]}
                    echo  "Connecting input:$in_l/$in_r to output: $out_l/$out_r"
                    amixer -D hw:DSP cset numid=5 $in_l,$out_l,0 > /dev/null 2>&1
                    amixer -D hw:DSP cset numid=5 $in_r,$out_r,0 > /dev/null 2>&1
          done       
done
if [ "$z" != "y" ] ; then echo "No working connection identified..." ; exit 1 ; fi
}

function scanoutputs () {
for k in  $(seq 0 $cnt_o) ; do
     out_l=${outputs_left[$k]}
     out_r=${outputs_right[$k]}
     echo  "Connecting input:$in_l/$in_r to output: $out_l/$out_r"
     amixer -D hw:DSP cset numid=5 $in_l,$out_l,32768 > /dev/null 2>&1
     amixer -D hw:DSP cset numid=5 $in_r,$out_r,32768 > /dev/null 2>&1
     aplay  -D$alsainterface -fcd "$track" > /dev/null 2>&1 &
     echo "Playback started..."
     echo -n "Any sound ? (y/(N)):"
     read z
     if [ "$z" == "y" ] ; then echo "Identified outputs: $out_l/$out_r" ;  break ; fi 
     amixer -D hw:DSP cset numid=5 $in_l,$out_l,0 > /dev/null 2>&1
     amixer -D hw:DSP cset numid=5 $in_r,$out_r,0 > /dev/null 2>&1
done
}

echo "Generating test-track..."
generate_track
init_matrix
echo "Scan inputs..."
scaninputs
init_matrix
echo "Scan outputs..."
scanoutputs
echo
echo "Result: inputs: $in_l/$in_r outputs: $out_l/$out_r"

exit 0

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