Between the ER4XR and Aria 2, the ER4XR comes out ahead in several specs, while the Aria 2 wins on sensitivity and impedance. Overall, the ER4XR scores 39.7 and the Aria 2 scores 65.4 on our Mars Score.
Which should you buy?
The Aria 2 is the clear pick on raw spec strength, leading by 25.7 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
The ER4XR doesn't pull ahead on any single popular-comparison spec — its strengths sit in the spec table groups rather than the headline advantages.
Pick the Aria 2 if you care most about sensitivity and impedance. Its strongest claims are sensitivity, impedance.
Both ship with comparable driver count, detachable cable, so those specs don't separate the two — focus on the differences below.
Bottom line: the Aria 2 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Etymotic - ER4XR wins
- No decisive advantages.
Why Moondrop - Aria 2 wins
- ▲Sensitivity — 24.49% more. 122 dB vs 98 dB.
- ▲Impedance — 13.00 Ω less. 32 vs 45.
Spec comparison
Drivers
| Spec | Etymotic - ER4XR | Moondrop - Aria 2 |
|---|---|---|
| Driver count | 1 | 1 |
| Driver types | Balanced Armature | Dynamic |
| Impedanceⓘ | 45 Ω | 32 Ωlead |
| Sensitivityⓘ | 98 dB | 122 dBlead |
Build
| Spec | Etymotic - ER4XR | Moondrop - Aria 2 |
|---|---|---|
| Detachable cable | true | true |
| Connector | MMCX | 0.78mm 2-pinlead |
Frequently asked
Spec-level deep dives
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