GRADIENT SW-63

The Gradient SW-63 was a global success. Shortly after its launch, there was a demand for a similar product for the original Quad ESL speaker. The Quad ESL or ESL-57 was the world's first full range electrostatic speaker. It was produced in 54,000 units from 1957 until 1985. The Quad ESL-57 had attained a reference speaker status worldwide. Its only challenge was reproducing low frequencies, which electrostatic technology couldn't handle.

In 1992, Gradient introduced the Gradient SW-57 additional bass unit, which was acoustically and visually matched to work perfectly with the legendary Quad ESL speaker. The included active crossover also brought other useful features such as tone adjustments and overvoltage protection for the sensitive ESL speaker. The bass unit was installed as a stand for the Quad ESL speaker, elevating it to a more favourable listening height.

Gradient SW-S was bringing the powerfully open and uncolored bass of Gradient Revolution available to be used along with other speaker models or increasing the capacity of Gradient Revolution Active speakers. Each unit of the system included two 12" long throw custom made woofers which extended the lower cutoff frequency to 20Hz. It was also possible to use only one piece of Gradient SW-S positioned in the middle between the loudspeakers and driven in mono.

Repaired original 12" woofer for Gradient SW-63 and Gradient Revolution MK I - MK II loudspeaker models.