high-frequency isodynamic speaker 10gi-1-4. soviet acoustics

10gi 10gi1 10gi14 6gdv acoustics advanced amplifier analog audio background change coil component contacts cotton damper disassembled electrical emitter ferrite glaze hale highfrequency isodynamic kert loudspeaker membrane module plasticine power rear recording repair seals sound soviet speaker square studio style subwoofer system tape technology thread threeway tools transport tweeter volume white wires