Weird. I have the same laptop and the same A07 BIOS (which is also the latest one). And my audio works perfectly in regular Ubuntu 16.04 (Unity7). Even working with kernel 4.4.
Xubuntu may well have different audio interfaces. But I also find it curious I don't see any haswell/broadwell audio messages like yours in my 'dmesg'.
Weird. I have the same laptop and the same A07 BIOS (which is also the latest one). And my audio works perfectly in regular Ubuntu 16.04 (Unity7). Even working with kernel 4.4.
Xubuntu may well have different audio interfaces. But I also find it curious I don't see any haswell/broadwell audio messages like yours in my 'dmesg'.