Had some time for fiddling today…
Still no success with the Max2Play-Software, so i tried to Beocreate Original-Software (Bang&Olufsen). With this, i reinstalled the DSP-profile and then it worked.
Re-burned the Max2Play-Image to the SD-card and it still plays sound. So it seems like there has been a problem with the DSP-profile-installation via Max2Play
