STAX in-the-ear earspeaker SR-003MK2 as well as SRS-002 features an open-air type structure that inevitably cause sound leakage, and therefore they are sometimes not suitable for outdoor use until now. Also, since their housing part is large and heavy compared with usual earphones, it is hard to obtain the stable fit feeling. The CES-A1 (CC-A1+ET-A1) has been developed in order to clear these problems.
A lot of innovations are incorporated into the sealing cover CC-A1 to bring full potential of SR-003MK2 and SR-002 into play. Visitors at the event hall listened to the sealing cover effect, and their opinions have been reflected in refining the cover. After repeated measurements and auditions as well as dozens of trial productions the sound leakage has been suppressed enabling listening to music in the outdoors without spoiling the tone quality of electrostatic type sound element.
The ear chip ET-A1 provides with different elastic hardness each for ear hole touching portion and for ear pinna touching portion. This has improved the fit feeling and close contact. Moreover, the opening has been made elliptical to fit in common with many ear holes, and also improving contact tightness of outside ear passageway has controlled the loss of low-frequency region.