For many years Klark Teknik has been at the forefront of equaliser design, and have carried our detailed research into optimum filter response characteristics, including their sonic performance. The Series 300 range of equalisers is a direct result of this research. It should be noted that graphic equalisation cannot always overcome all frequency response related problems. There are applications where the ability to cut and boost the response at a particular frequency, or over a certain bandwidth other than the equaliser specified one, is required to overcome exceptionally difficult response anomalies or narrow band feedback problems.