Massdrop Plus Universal IEMs

The first in-ear monitor tuned by Massdrop from the ground up, the Plus features a novel sound signature that combines aspects of a number of community-favorite IEMs. With three Sonion balanced-armature drivers per ear, it delivers extended bass, clarity, and a sound that leans toward full and fun. And while it’s a universal IEM with removable ear tips, the Plus is the next best thing to a custom fit. That’s because it’s based on custom designs worn by musicians on stage for more than 20 years, and the shape is derived from the average of thousands of custom shells. The dampers, crossovers, and tubing were carefully selected after a year of R&D. Finally, every part of the process—from development and 3D printing to assembly and QC—was done in the USA.

With the Plus, our goal was to capture the technicalities of a professional audio monitor while adding the sub-bass that many music lovers appreciate—an element often lacking in monitors of this type. The final tuning resembles a reference monitor, plus elevated bass that extends flat and low from 100 Hz down to 10 Hz. The sound is big, layered, and impactful, with the vented bass drivers allowing more airflow and a lower extension than the typical IEM. This produces a rumble and movement of air when the bass is called for, and may even cause the Plus to sound like a hybrid IEM, though all drivers are balanced armature. There’s a plateau in the upper mids for balance and clarity, with a slight dip in the sibilance region and enough treble air to create a sense of openness. Each pair is handmade with QC measurements, such as frequency response, occurring at multiple points in the process to ensure replication of the target sound.

“There’s honest-to-goodness rumble with these little monsters. They are—for lack of a better phrase—fun as hell when you’re listening to Kendrick Lamar or Four Tet. Yet all the while I never felt myself wanting more midrange presence or clarity. Somehow the Plus retains a reference tuning throughout all my test tracks and comparisons. Oh, and they’re extraordinarily comfortable.” - MuppetFace on Head-Fi

"I've been listing to these next to CA Andromeda, CA Orion, JH13 original, and the AAW W900 extensively over the past few weeks. My take on the Plus is that it's the best thing you can get under $1K." - Vansen on SBAF

"Frankly, it’s pretty amazing. Clarity is through-the-roof fantastic! It makes just about everything else at my disposal sound like there are differing degrees/layers of veil yet to be removed. However, the Plus stays harshness and hardness free...The shell shape is form fitting and flat to the ear...I really do love the fit of the Plus." - shotgunshane on SBAF