Hi folks, hmm, looks like the only way is using a hotspot, either one as a vitual one using hostapd (or some similar software).
But this is just what I wanted to avoid, as every software between streaming device and receiving device will cause delays (which I also get when using a router i.e. some Fritz!Box or similar). So at the moment it looks like there is no "wireless-crossover-connection". I also never heard of it, that it is possible at all. Well, still keep searching. At the moment I am falling back to the combination Host 1 > AP -> Host 2 Thanks for all the help. See it as solved, but I will let this question some time open, and then mark it as [SOLVED] in a few days. Best regards Hans