The In-Ear Monitor ET IET4 are assembled by combining four Balanced Armature type receivers with a three-way cross-over. The In-Ear Monitor ET IET4 have a dual driver type subwoofer that lets you play full-bodied and balance basses, a dedicated receiver for the mid-range that makes a clear and dynamic sound, and a tweeter that emits crystal clear acute frequencies. The result is a total acoustic immersion that conveys the listener every single detail and emotion. The sound quality is excellent and makes In Ear Monitor ET-IET4 professional systems dedicated to very demanding musicians and entertainers. The isolation of about 26dB from the outside allows you to listen securely at a lower volume. Like other In Ear Monitors, they are compatible with wireless transmission systems and portable media devices.