Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Sennheiser - HD 660S2 | Sennheiser - HD 660S2 |
|---|---|---|
| Driver size | 42 mm | 38 mm |
Between the HD 660S2 and HD 660S2, the HD 660S2 comes out ahead in driver size, while the HD 660S2 wins on several specs. Overall, the HD 660S2 scores 52.5 and the HD 660S2 scores 51.2 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (52.5 vs 51.2). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the HD 660S2 if you care most about driver size. The biggest gaps in its favor are driver size. The single most decisive one: Driver size — 10.53% more. 42 mm vs 38 mm.
The HD 660S2 similarly does not carry a headline advantage on the popular specs — look at the full table for category-specific deltas.
Both ship with comparable battery life, active noise cancellation, spatial audio, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Sennheiser - HD 660S2 or Sennheiser - HD 660S2?
Sennheiser - HD 660S2 leads the current Mars Score by 1.3 points.The more useful decision is the trade-off behind that result: compare driver size against the way you will actually use the product.
Choose Sennheiser - HD 660S2 if…
Sennheiser - HD 660S2 has the measurable edge on driver size mm.
Choose Sennheiser - HD 660S2 if…
Sennheiser - HD 660S2 does not lead a decisive measured field here, so choose it for price, ecosystem, design, or availability when those matter more to you.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Sennheiser - HD 660S2 wins
- ▲Driver size — 10.53% more. 42 mm vs 38 mm.
Why Sennheiser - HD 660S2 wins
- No decisive advantages.
Spec comparison
Design
| Spec | Sennheiser - HD 660S2 | Sennheiser - HD 660S2 |
|---|---|---|
| Type | over-ear | over-ear |
| Weight | 260 g | 260 g |
| Water resistance | none | none |
Audio
| Spec | Sennheiser - HD 660S2 | Sennheiser - HD 660S2 |
|---|---|---|
| Driver sizeⓘ | 42 mmlead | 38 mm |
| Impedanceⓘ | 300 Ω | 300 Ω |
| Sensitivityⓘ | 104 dB | 104 dB |
| Active noise cancellationⓘ | false | false |
| Transparency mode | false | false |
| Spatial audioⓘ | false | false |
Battery
| Spec | Sennheiser - HD 660S2 | Sennheiser - HD 660S2 |
|---|---|---|
| Battery lifeⓘ | 0 h | 0 h |
| Fast chargeⓘ | false | false |
Connectivity
| Spec | Sennheiser - HD 660S2 | Sennheiser - HD 660S2 |
|---|---|---|
| Bluetoothⓘ | 0 | 0.0 |
| Multipointⓘ | false | false |
| 3.5mm jack | true | true |
| LDACⓘ | false | false |
| aptX HDⓘ | false | false |
Frequently asked
Which has better battery life, HD 660S2 or HD 660S2?+
HD 660S2 lasts 0 hours vs 0 hours.
Do HD 660S2 or HD 660S2 have active noise cancellation?+
Neither model has active noise cancellation.
Which supports LDAC, HD 660S2 or HD 660S2?+
Neither supports LDAC.