After getting the matrix-creator software installed, I can not properly access the microphones. Alsa (arecord -l) only lists "Dummy [Dummy] and 8 Dummy PCM decives.
Thanks for your help. I tried arecord, but the result is not only very low in volume, but noisy and distorted.
So, something happens, but maybe there is some other problem.
This recording demo records all mics at the same time and converts them to wav audio. This I could see if something is wrong with the mics.
IMPORTANT: before running the example please stop the MALOS service using: sudo pkill malos
after this malos should not appear listed in the processes . To check the active processes use top.