The JENSEN® "C" series speakers were developed because the world's supply of cobal (Co in AlNiCo) slump, making this raw material more expensive. While ceramic magnets are larger in size than comparable AlNiCo magnets of the same gauss strenght, their cost is lower. "C" series JENSEN® speakers use same cones and voice coils comparable to our AlNiCo series speakers, thus providing a similar tone but at a reduced price. Therefore they soon became the choice of a wide variety of amplifier manufacturers in the 60's.