Between the IE 200 and IER-M9, the IE 200 comes out ahead in sensitivity, while the IER-M9 wins on driver count. Overall, the IE 200 scores 62.5 and the IER-M9 scores 54.5 on our Mars Score.
Which should you buy?
The IE 200 is the clear pick on raw spec strength, leading by 8.0 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.
Pick the IE 200 if you care most about sensitivity. The biggest gaps in its favor are sensitivity.
Pick the IER-M9 if you care most about driver count. Its strongest claims are driver count.
Both ship with comparable impedance, detachable cable, so those specs don't separate the two — focus on the differences below.
Bottom line: the IE 200 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Sennheiser - IE 200 wins
- ▲Sensitivity — 15.53% more. 119 dB vs 103 dB.
Why Sony - IER-M9 wins
- ▲Driver count — 4.00 more. 5 vs 1.
Spec comparison
Drivers
| Spec | Sennheiser - IE 200 | Sony - IER-M9 |
|---|---|---|
| Driver count | 1 | 5lead |
| Driver types | Dynamic | 5 Balanced Armature |
| Impedanceⓘ | 18 Ω | 18 Ω |
| Sensitivityⓘ | 119 dBlead | 103 dB |
Build
| Spec | Sennheiser - IE 200 | Sony - IER-M9 |
|---|---|---|
| Detachable cable | true | true |
| Connector | MMCX | MMCX |
Frequently asked
Spec-level deep dives
More from the same brands
vsMars is reader-supported. When you buy through links on our site, we may earn an affiliate commission at no extra cost to you. Learn more.