I had an old Stewart Warner radio that had an open field coil. Believe it or not, I hand wound the voice coil with magnet wire. Worked great!I could have easily replaced the speaker with a fixed magnet type, but I wanted to keep the old speaker. It took hours and hours and hours to wind! I would spend an hour or so every day winding while watching TV or listening to the radio or CD. After a couple weeks, I finally finished. Lots of work, but I'm glad I did it!