The driver used in the other Motorolas (such as KSN1005), the ones that roll in around 3.5 khz use a driver whose diaphragm is connected to the piezo element via a small metal lever, and this lever apparently resonates around 5K... giving a harsh one note cymbal tone.

The larger driver in the KSN1025, and there is a screw on driver only version, has the diaphragm, or cone, glued directly to the piezo element. Anyway, it is a much smoother sounding horn.

I have had several of these burn out in PA speakers. The amp was a 240 series Peavy PA head. Generally Peavey stuff is well designed, so I don't know if there is an inherent occillation problem. We were occasionally picking up two-way radio signals over the PA. Perhaps some RF sneaking in? Anyway, there was quite literally SMOKE coming out of the KSN1025! I had several of these burn at that same place (a civic center). Who knows.

But, does anyone have a spec sheet/response graph of the KSN1188a screw in driver? This is the large (4" dia) one that rolls in at 800hz. How do these work for home stereo? Or are they limited to PA speaker use?

FYI, I have been able to cross over these Motorolas easily by wiring an 8 ohm, 20 wt resistor parallel to Motorola drivers.