Airfoil alternative for Raumfeld Cube

First of all apologies for writing in English, I can understand German but writing is still terrible. So, I recently bought Raumfeld Cube and am terribly dissapointed with a lack of spotify and airplay. I would like to stream audio (from any application eg. firefox, vlc, spotify) from my macbook to the speakers just like airfoil allows one to do when using airplay. However, I have been unable to find any upnp application for the same thing for mac. There is jamcast and stream what you hear, which are similar for windows, but absolutely nothing for mac. Any help would be much appreciated.