Why not disconnect one end of the capacitor on the working set of speakers, and measure the capacitance. They whould be bipolar capacitors. Please

post pictures of it also.
Reconnect them after measurements. Use a heat sink when you desolder and solder them back.
If someone got schematics of this boombox ...things would have been much easier. We can get the information from the crossover circuit part.
Radiomuseum got the schematics for Telefunken Studio 1M . I'm not a member there.. Let me see what I can do.
http://elektrotanya.com/telefunken_hifi ... nload.html
Currenly I am travelling with my work computer and it won't allow me to download any programes on it.