Malos driverconfig problem

I have recently bought the Matrix Voice and popped in onto my rpi 3. I installed the matrix-creator-malos and that works fine. I can run arecord and it produces a wav from mic_channel8 with hearable sound but rather quiet. But when I try to configure the driver (setting gain for example), the arecord command stops working (that is: the command runs indefinite and my wav has 0 bytes, but no errors are thrown). If I reboot my raspberry pi, the arecord command works again but alas the same volume.

My arecord command:

arecord -r 16000 -c 1 -t wav -f S16_LE -D mic_channel8 -d 10 q.wav

And the Javascript code taken mainly from test_micarray.js:

var creator_ip = process.env.CREATOR_IP || '’
var creator_micarray_base_port = 20037
var zmq = require(‘zmq’)
var matrix_io = require(‘matrix-protos’).matrix_io
var configSocket = zmq.socket(‘push’)
configSocket.connect(‘tcp://’ + creator_ip + ‘:’ + creator_micarray_base_port /* config */)
function setupMicarray() {
var micarray_cfg ={
gain: 16 // set gain for all microphones
var config = matrix_io.malos.v1.driver.DriverConfig.create({
micarray: micarray_cfg

This script runs without error. And also notable: the test_everloop.js also stops working after running the above Javascript. If I reboot again test_everloop.js works again.

First I have no idea what the value 16 means for gain (let alone the rest of the angles, distances, etc in MicArrayParams) and I must say that I have pumped all the capture values to 100 of the Dummy card with the alsamixer command (which I stored with sudo alsactl store). Anybody encountered similar weirdness or am I missing something here (prolly some documentation)?