I've been in the occasional habit of watching music videos late at night via a laptop or iOS device Bluetoothed to my Bose Soundtouch speakers. And very fine an experience it's been. But recently I've found that there is a bit of latency in the system. Not a millisecond or two, but three, four or even five whole seconds' delay between the video and the audio. And it isn't just YouTube (who I was going to have a rant at), but iPlayer, ITVHub and all of the regular video playback apps/websites. Now, all of these work perfectly well through my TV to a Bose soundbar, so why do they not work when a TV is not involved? This appears to be across operating systems, so wtf is going on?