In-ear monitors have become the preferred choice for audiophiles who need portability without sacrificing sound quality. Using a standardized IEC 60318-4 (711) coupler with Room EQ Wizard, we measured frequency response, total harmonic distortion, and passive isolation for ten popular IEMs spanning budget to mid-fi price points. The Moondrop Blessing 3 delivered the most neutral frequency response in our testing, tracking within 2dB of the Harman IE 2019 target from 20Hz to 10kHz. The Truthear x Crinacle Zero: RED continued to offer incredible value at $55 with its dual dynamic driver configuration producing authoritative bass without bleeding into the mids. The Sennheiser IE 600 impressed with its single 7mm TrueResponse driver and exceptional build quality. We also tested isolation performance, finding that the Etymotic ER2XR provided 35-42dB of passive isolation — enough to use on airplanes without ANC.
Best In-Ear Monitors in 2026: 10 IEMs Measured for Frequency Response and Isolation
