My pragmatic solution:after setting up a schedule of disabling the 2.4Ghz signal during later evening hours, I have again perfect wireless HiFi during these hours. During the day, 2.4Ghz is automatically enabled to be available for older 2.4Ghz only devices in our home network.
That isn't really feasible for people who really need 2.4ghz wireless on all the time or for people who live in apartment blocks where there are lots of wireless signals floating around. Interesting idea though. Must try it out and see how well it works. For me personally I managed to almost eliminate the problem by using a really small (0.5m) optical cable for the connection that is heavily shielded and changing the channel on the wireless router to 11. Doing only one of those didn't work but doing them together fixed things. Obviously that is also not an idea solution if someone is needs a much larger cable. It's quite annoying sticking the transmitter right next to the computer because of the short cable.