Monday, February 21, 2011

Nothing's Easy about Cone Making

We've been working non-stop on CS1.7 development since before Jim passed away. It's a super fun but really hard project. The bulk of the work has been developing the CS1.7 woofer (which in turn will be used for a variety of other new products, but lets be suspenseful for now, shall we?). Not surprisingly, we wanted to use a star diaphragm for the new woofer since it's working out so well in the CS3.7, but improving upon the CS1.6 woofer isn't so simple.

The star diaphragms each have to be engineered on their own to suit specific design goals, and can't simply be scaled up or down from previous iterations. Jim had developed a calculator to simplify the base modeling of these diaphragms but it only gets us started. From there, we do some solid modeling and finite element analysis to predict resonance behavior, but even that only gets us halfway there. Once we find a geometry that models well, we machine a mold from hard plastic on one of our CNC machines. We can then press prototype diaphragms, build drivers and measure.

Jim probably went through 60 diaphragms on the CS3.7 project before he finalized them. Granted, he was just learning whether the geometry would work, so a lot of trial error was in order. We're not even to 10 yet on the CS1.7. So many prototypes and drawings get chalked up as "learning experiences". This begs the question - what happens to all the failed diaphragms? I make pinwheels for my daughter to paint!