A magnetic motor system for driving a loudspeaker voice coil. The system has first and second parts that define a volume for receiving a voice coil. The first and second parts each have a respective permanent magnet with first and second sidewalls that extend in a direction away from the volume. The first sidewall slopes in a direction towards the second sidewall as the sidewalls extend away from the volume. The first and second parts further have respective guide members for channelling lines of magnetic flux in a return path between the permanent magnets.