[Kasudain]

     I have a pair of old Magnavox headphones that I want to use with my computer, so I took the 3.5mm cord from newer headphones and disassembled the Magnavox set down to the speakers. The speakers work, as does the cord. I spliced the positive cord to the positive wire soldered to the speakers, and the negative cord to the negative wire soldered to the speaker, but no sound comes out of the speakers. What have I done wrong, any ideas?