Horn loudspeakers are still widely used in some markets in rural and urban areas. Once the sound film of horn loudspeakers is lost, it is necessary to ensure the correct installation of the sound film. Here is a method to solve this problem relatively easily. The installation can be carried out in two steps.
The first step is to select paper of appropriate thickness and cut two loose ~10mm paper strips 20mm longer than the diameter of the center piece. Then put the two paper strips perpendicular to each other on the center piece (the position should be taken in the center). In order to prevent them from moving, you can stick them with a little paste. Insert both ends of the paper strip into the magnetic gap. Align the voice coil on the sound film with the magnetic gap and press it down gently. Due to the existence of the paper strip, the position of the voice coil at this time is exactly in the middle of the magnetic gap, and will not be deflected. Coat the edge of the sound film with all-purpose glue and cover the upper cover of the sound head. Align the screw holes and tighten the screws. And record the relative position of the upper cover and the sound head in the appropriate position. Leave it for 8 hours. After the universal glue is completely dry, you can unscrew the screw and remove the upper cover. At this time, the sound film has been glued to the upper cover.
The second step is to solder the leads to the terminal. Take off the two paper strips, and then put the upper cover back, paying attention to align the original marks. At this time, you can use the multimeter R× block or 1.5V dry battery, while constantly touching the two terminals, making a "click" sound, and tap the upper cover until the "click" reaches the maximum and there is no rubbing sound. Tighten the fixing screws gradually. When tightening the screws, the screws should be tightened symmetrically, instead of tightening one screw very tightly before tightening the second screw.
