There is a thread on driver which is my favorite model, the 4540ND I try and use this model when ever possible because it has the smoothest sound and has extreamly high extension. This will screw into a CH3 directly. The draw back to this model is that the reccomended crossover point is 1900hz. This driver can be, and is used in systems with a 1600hz crossover point. It needs to be derated in power handling in this case. For home audio and home theater 1600hz is fine. For high power output the 4552ND driver is a better choice and a screw on adaptor would have to be found.

The 4540ND is my choice and I most always have to use an adaptor to convert them from their screw on mount to a flange mount. These drivers will most certainly need more attenuation in your Pi crossover than the 2002 driver. With out an addition 2-4 db of attenuation depending on the horn you will find the sound very harsh and overly bright as a direct drop in. But then you need different attenuation from an Altec, to a JBL, to an Eminence as well.

I just received these in 16ohm no they will seem a little less sensitive. I havnt worked with them yet.

Bill