Here a more in depth coverage of the Norwegian's system.
This comment from Tjorborn pretty much sums it up: This is something I didn't need and probably never should have started. But I had to do it.
He came across the opportunity to buy a large lot of drivers which were sitting in his storage for some time and finally brought to some use.
The idea behind this was to build something which the developers of these chassis would have done when asked to provide a speaker for a cinema which is supposed to fill a large room and at the same time is not very deep and can be placed behind the screen.
Yesterday some impressive reproduction of organ music could be heard in the hallway and it sounded very lifelike even from outside of the room. And it achieved that even with out the subwoofer array being hooked up yet.
Here a short clip to get an impression:
When I first saw this speaker it put a smile on my face and I think this creation is a perfect example of the spirit and idea behind the ETF. It reflects the passion and drive which keeps pushing people to explore new things.