First test of 1935 UFA Bauer Klangfilm field coil horn speaker

First test of 1935 UFA Bauer Klangfilm field coil horn speaker . After a long period of work, finding and assembling small parts, the loudspeaker is almost ready to play again. The Bauer system Klangfilm field coil horn driver is an ultra hard to find speaker system from the past ( made around 1935 ) and has a backloaded voicecoil that is covered at the back. Here you can see when its open and sounding in both directions. I used 150 V DC for testing and the impedance of the voice coil is 4 Ohm. please also see my second video when its ready mounted. Enjoy !