This is just a minor update to my POC3 TH design. I basically replaced the Dayton PA310 driver with an Eminence Kappalite 3012LF-4 driver.
The Kappalite's greater Xmax and lower impedance not only will increase the TH's power handling capability, it will also make it a better match for a portable PA system
driven off of a 12V power source (e.g. car audio
amplifier), which is how I use it for the most part these days.
The HornResp parameters are as
The predicted performance is as
The upgrade was a success, and the TH is now capable of being powered to a
higher level before audible distortion sets in. Pictured below is a
linearity test that I performed on the TH recently, with levels all the way
up to 40V (HornResp predicted that the driver would exceed Xmax in the
passband with 33.5V input). Note that the compression visible on the 40V
graph actually might be primarily due to the mic being overloaded. At lower
levels there is virtually no difference at all between the response at
different voltage levels, which is likely why I think it has an "effortless