OpenVoiceOS/buildroot-external/rootfs-overlay/etc/asound.conf

pcm.!default {
    type pipewire
    playback_node "-1"
    capture_node  "-1"
    hint {
        show on
        description "Default ALSA Output (currently PipeWire Media Server)"
    }
}

ctl.!default {
    type pipewire
}