64 Audio is proud to introduce our newest four driver custom in-ear monitor, A4s. This complete redesign of our four driver platform is elevated by the Dynamic low frequency driver, making this 64 Audios second hybrid custom IEM. Along with that major update, inside A4s is our Tia technology, LID and our patented Apex and 3Dfit tech. While this is targeted at musicians looking for a rich enveloping monitoring experience, the frequency response, detail, and soundstage capabilities of A4s exceed other audiophile products at almost any price point.

Technology
Exclusive technologies that challenge traditional in-ear monitor designs to give you the absolute best listening experience.

tia
Our industry-first, tubeless technology eliminates sound-altering dampers and tubes. This reduced resonance reveals a new level of resolution and transparency.

apex
This pneumatically interactive vent relieves air pressure in a sealed ear canal, alleviating listener fatigue and opening the soundstage.

LID
LID is a correctional circuit that presents a flat impedance to the amplifier, resulting in a sound devoid of artificial coloration.

3DFIT
A new way of manufacturing custom in-ear monitors preserves the details of your ear impressions for the most comfortable-fitting IEMs possible.