@phusis , Hi, yes the Synergy Horns, never heard the real thing but a friend and I roughly assembled out of stiff cardboard a mock up and we were both seriously impressed.
Way back I got a DIY design out of either Speaker Builder magazine or Sound Practices, can't remember which. It was an Edgar horn for mids and easy to build, which was at the time considered as the reference for midrange purity. I later helped build an Edgar horn system which is most unattractive to look at, a pile of ugly boxes but loved the sound. There were no subs at this stage unfortunately.
I firmly believe if more people heard speakers of this ilk with their effortless dynamics and convincing realism some would find a way to incorporate them into a domestic setting.