Between the ER4XR and IER-Z1R, the ER4XR comes out ahead in several specs, while the IER-Z1R wins on sensitivity and impedance. Overall, the ER4XR scores 39.7 and the IER-Z1R scores 50.3 on our Mars Score.
Which should you buy?
The IER-Z1R is the clear pick on raw spec strength, leading by 10.6 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 IER-Z1R if you care most about sensitivity and impedance. Its strongest claims are sensitivity, impedance, driver count.
Both ship with comparable detachable cable, so those specs don't separate the two — focus on the differences below.
Bottom line: the IER-Z1R 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 Sony - IER-Z1R wins
- ▲Sensitivity — 5.10% more. 103 dB vs 98 dB.
- ▲Impedance — 5.00 Ω less. 40 vs 45.
- ▲Driver count — 2.00 more. 3 vs 1.
Spec comparison
Drivers
| Spec | Etymotic - ER4XR | Sony - IER-Z1R |
|---|---|---|
| Driver count | 1 | 3lead |
| Driver types | Balanced Armature | 2 Dynamic + 1 Balanced Armature |
| Impedanceⓘ | 45 Ω | 40 Ωlead |
| Sensitivityⓘ | 98 dB | 103 dBlead |
Build
| Spec | Etymotic - ER4XR | Sony - IER-Z1R |
|---|---|---|
| Detachable cable | true | true |
| Connector | MMCX | MMCX |
Frequently asked
Spec-level deep dives
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