I partly own a pair of Olympians with Elysian horn sub-bass that are installed in a music venue, and I have set them up at different venues over the past few years. Having bass horns that extend all the way to below 20Hz is something that reflex loaded bass cannot compare with. On the other hand, I use a pair of Acapella plasma tweeters at home, and they are by far the best tweeters I have ever used. The Olympians use a trumpet horn for the tweeter and also has a slot loaded supertweeter on top. The frequency response is well extended, but dispersion is narrow, and they are designed to work over a larger distance. I have not heard the Acapella Sphäron, but I did spend quite some time listening to the Hyperion in Munich this spring. I did like the sound, but I feel the bass integration is not as seemless as a well set up Olympian. The Olympian however does require very careful set up and room matching, and the speakers allow adjustments in various parameters at the bass and sub-bass crossovers, as well as physical time alignment between the various drivers. Kevin Scott will set up the speakers at customers's homes anywhere in the world.