Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Sennheiser - HD 660S2 | Sony - WH-1000XM6 |
|---|---|---|
| Driver size | 38 mm | 30 mm |
| Weight | 260 g | 254 g |
| Active noise cancellation | false | true |
| Spatial audio | false | true |
| Multipoint | false | true |
| LDAC | false | true |
Between the HD 660S2 and WH-1000XM6, the HD 660S2 comes out ahead in driver size, while the WH-1000XM6 wins on weight / active noise cancellation. Overall, the HD 660S2 scores 51.2 and the WH-1000XM6 scores 69.4 on our Mars Score.
Which should you buy?
The WH-1000XM6 is the clear pick on raw spec strength, leading by 18.2 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 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 — 26.67% more. 38 mm vs 30 mm.
Pick the WH-1000XM6 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight, active noise cancellation, spatial audio, among others. The single most decisive one: Weight — 6.00 g less. 254 vs 260.
Both ship with comparable water resistance, so those specs do not separate the two — focus on the differences below.
Bottom line: the WH-1000XM6 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: Sennheiser - HD 660S2 or Sony - WH-1000XM6?
Sony - WH-1000XM6 leads the current Mars Score by 18.2 points.The more useful decision is the trade-off behind that result: compare driver size, battery life, weight 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 Sony - WH-1000XM6 if…
Sony - WH-1000XM6 has the measurable edge on weight g, has anc, has spatial audio.
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 — 26.67% more. 38 mm vs 30 mm.
Why Sony - WH-1000XM6 wins
- ▲Weight — 6.00 g less. 254 vs 260.
- ▲Has Active noise cancellation.
- ▲Has Spatial audio.
- ▲Has Multipoint.
- ▲Has LDAC.
- ▲Battery life: 30 h vs 0 h.
Spec comparison
Design
| Spec | Sennheiser - HD 660S2 | Sony - WH-1000XM6 |
|---|---|---|
| Type | over-ear | over-ear |
| Weight | 260 g | 254 glead |
| Water resistance | none | none |
Audio
| Spec | Sennheiser - HD 660S2 | Sony - WH-1000XM6 |
|---|---|---|
| Driver sizeⓘ | 38 mmlead | 30 mm |
| Impedanceⓘ | 300 Ωlead | 16 Ω |
| Sensitivityⓘ | 104 dBlead | 101 dB |
| Active noise cancellationⓘ | false | truelead |
| Transparency mode | false | truelead |
| Spatial audioⓘ | false | truelead |
Battery
| Spec | Sennheiser - HD 660S2 | Sony - WH-1000XM6 |
|---|---|---|
| Battery lifeⓘ | 0 h | 30 hlead |
| Fast chargeⓘ | false | truelead |
Connectivity
| Spec | Sennheiser - HD 660S2 | Sony - WH-1000XM6 |
|---|---|---|
| Bluetoothⓘ | 0.0 | 5.3lead |
| Multipointⓘ | false | truelead |
| 3.5mm jack | true | true |
| LDACⓘ | false | truelead |
| aptX HDⓘ | false | false |
Frequently asked
Which has better battery life, HD 660S2 or WH-1000XM6?+
WH-1000XM6 lasts 30 hours vs 0 hours.
Do HD 660S2 or WH-1000XM6 have active noise cancellation?+
WH-1000XM6 has active noise cancellation; HD 660S2 does not.
Which supports LDAC, HD 660S2 or WH-1000XM6?+
WH-1000XM6 supports LDAC; HD 660S2 does not.