T25a Electro Voice Midrange Horn Driver Control Vintage Ev Electrovoice(41.6% similar) I've had it for many years, unused, and no testing beyond an ohmmeter reading has ever been done by me. There is sound when leads are attached. Details:all metal construction the 8HD diffraction horn is cast aluminum. My ohmmeter needle moves steadily when the dial is turned numbering has ...(September 7th, 2018)