Field coil speakers have always been more expensive to make. When permanent magnet speakers became available, the industry moved to them quite quickly due to the fact that they were cheaper.
Like a lot of things in audio (tubes to transistors, LP to digital), the move from field coil to permanent magnets was fueled more by cost motivation than performance. Field coils are a rising star these days in loudspeaker technology. Although more expensive, they are otherwise an easy way to get the speaker to sound more transparent.
Like a lot of things in audio (tubes to transistors, LP to digital), the move from field coil to permanent magnets was fueled more by cost motivation than performance. Field coils are a rising star these days in loudspeaker technology. Although more expensive, they are otherwise an easy way to get the speaker to sound more transparent.