Cube Audio's website (regarding the F10 Neo driver in the Nenuphar):
"
Cones and whizzers"
"Once we had the motor ready and capable to control heavier moving cones and suspensions mass, it was time to do the cones. Plenty of experience for experimenting with 8" drivers came in handy. We knew where to start with. But that was basically it. 10" is a completely different beast. For a very long time we were not satisfied with the sound. There was a time where we didn't have more bass than from 8" driver which is basically pointless. Multiple times we had a prototype cone geometry that on measurements was absolutely linear and looking amazing to the point that studio monitors could be really envy, but the sound was dull and boring. Those times were very frustrating. Sometimes we thought that it is impossible to do a really amazingly sounding 10" fullrange driver. But we never gave up and experimented more and more with even more drive every next day.
It was definitely worth it. The final design consist of 4 cones. One being the main cone and 3 whizzer cones. The smallest cone is responsible for highest frequency range. With only one standard whizzer we never would never be able to go up to 18 kHz with a driver that in proper cabinet reaches 30 Hz region. So adding that little whizzer, solved one of the issues that we had. But there were plenty more of them. When you add a whizzer to the cone, there is additional interference between the cone and the whizzer. The mini high frequency whizzer and the main whizzer got together really well and the sound was way better than without it. There was still a geometry issue present though. Its diameter, height, surface, geometry, stiffness, damping, coating all are a part of final sound equation.
To achieve the right amount of sound pressure in desired frequency region the most important of them all is geometry. There was one geometry that gave us amazing rich, colourful midrange, but on the other hand it interfered with the main cone in such a way, that a mods were pumping up mid frequencies. Since "shouty" vocals were not desired, we had to do something about it. Here's where the third whizzer comes into play. That is a very elegant solution to change the interference mods of the whizzer and the cone. Due to changed geometry and distance, amplitude of the modes decreased. As a result overall sound became sweeter, richer and more natural. At that moment we knew that this is the way to go."
More information on the driver design and approach here:
https://www.cubeaudio.eu/cube-audio-f10-neo
