Great photo of the different speakers together in situ. And, hate to say it, but I still think the 8000s are better looking than the 18s, but then I also think the 9s are better looking than the 20s. The amount of sound you get out of the 9s is astounding, especially considering their size. If you look at them, and think about massaging their volume into an equivalent box shaped speaker, you appreciate how truly small they are. There is a fair amount of electronic trickery involved that's apparent if you know something about both how speakers work sans electronic adjustments and how small the cabinet volume is for the woofers on a lot of B&O speakers. Take the 5s, a 15 inch subwoofer in a cabinet of 1.5 cubic foot volume that goes down well below 20 hz! Back in the 60s and 70s you'd need almost a refrigerator sized cabinet for that.
Years ago I encountered a device made called the Bassis. It was an electronic box that, for a sealed enclosure, let you force the driver to have whatever Q, resonance, and low frequency cutoff you desired, limited by the amount of power you had and how robust the driver was to handle the excursion and power. Since back then not many drivers in production speakers were not that robust there were limits to what you could accomplish, if you look at the woofers on the 5s or 9s you can tell they are very robustly designed and constructed to handle the boost and such. I find this a remarkably intelligent design approach, in general and especially for a company that desired to produce livably sized speakers with good bass response.
