I wanted to point out an interesting observation I made today regarding airplay. That is, airplay uses the EQ settings of the iPhone. While I believe the EQ settings are off by default, if you have the EQ turned on, airplay will use whatever EQ settings you currently have set. I mention this because I remember a while back I was, out of curiosity, trying out the EQ settings on my iPhone with a set of headphones and inadvertently left the EQ on and forgot about it. After several weeks of feeling like there was something off with the sound, I finally checked the EQ and realized that I had left it on.
In any case, I was curious if the EQ settings were operational while using airplay...and sure enough they are. Not only that, the EQ settings have a significant effect on the sound of the Beolit 12, much more than they do on earphones. I believe it is a matter of personal taste as to whether the EQ will improve or detract from the sound of the Beolit 12. Personally, I believe the Beolit 12 (and just about everything else) sounds better with the EQ off.
Nevertheless, being aware of the EQ is important for two reasons. First, if you are auditioning the Beolit 12, make sure the EQ on the iPhone you are using is off (at least initially). Second, if you feel that the sound of the Beolit 12 could use an adjustment (maybe for just a certain type of music), try the various EQ settings to see if one comports with your tastes.
By the way, the EQ settings on the iPhone are found at Settings>Music>EQ