A small speaker placed in the ear canal generates air pressure (sound pressure). This air pressure causes the eardrum to vibrate excessively, which can cause ear fatigue and even deafness.
The unique technology we have developed to reduce this problem is “apex (Air Pressure Exchange) technology”. Our earphones with apex technology have an “apex module” that acts as a “second eardrum” in the center of the vents that interact in the housing. This apex module relieves the air pressure generated by the small speaker in the sealed ear canal, which dramatically improves sound quality, and this technology minimizes ear fatigue while traditional earphones. It realizes a wide bandwidth sound that could not be achieved.

Apex m15 Modules are replacement modules developed for the earphone series “A-Series” and “U-Series” by 64 AUDIO. By adopting “dual ambient port”, in addition to achieving -15dB isolation in the 350Hz band, it cuts about 4dB in the “20Hz” band compared to Apex m20 Mudules, and the module is Apex m15. The low range can be attenuated by exchanging with Modules.

Like the Apex m20 Mudules, the Apex m15 Modules feature “apex technology” that provides a safer listening experience and a richer, more spacious sound while minimizing ear fatigue.