^ in the real world how much of that is audible that you can hear?
Break-up can be very audible and ruinous to the sound. You can still use drivers that run into severe break-up modes, but the response has to be heavily filtered to make the modes inaudible. Break-up modes are one of the reasons why I have never heard a full-range driver speaker that I have liked.
I should add that you can still make a perfectly fine speaker using titanium. You just have to properly filter out the cone break-up with the crossover circuit.