With an open-back design and an all-aluminum alloy CNC constructed frame, the Fosi Audio IM4 Open-Back In-Ear Monitors bring smooth and non-fatiguing sound at an affordable price point. The dual-magnet and dual-cavity design, paired with 10mm beryllium-plated diaphragms, are able to balance the efficiency of the in-ear monitors by reducing nonlinear distortion and optimizing airflow. With acoustics in mind, the rear chamber is filled with sound-damping material that eliminates resonant peaks and overall harshness.
Customizing the tonal signature of the IM4 in-ear monitors is possible with included eartips that boost bass and sub-bass frequencies. Taking that a step further, included brass and aluminum alloy nozzles are interchangeable for altering mid and high frequencies. An included 5N OFC silver-plated cable ensures a secure connection, featuring a 3.5mm plug on one end and two 0.78mm 2-pin connectors on the other.