Between the HD 660S2 and ULT Wear 2, the HD 660S2 comes out ahead in driver size, while the ULT Wear 2 wins on weight and active noise cancellation. Overall, the HD 660S2 scores 64.2 and the ULT Wear 2 scores 70.9 on our Mars Score.
Which should you buy?
The ULT Wear 2 edges ahead on the Mars Score (64.2 vs 70.9), but the 6.7-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the HD 660S2 if you care most about driver size. The biggest gaps in its favor are driver size.
Pick the ULT Wear 2 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight, active noise cancellation, multipoint, among others.
Both ship with comparable spatial audio, water resistance, so those specs don't separate the two — focus on the differences below.
Bottom line: the ULT Wear 2 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Sennheiser - HD 660S2 wins
- ▲Driver size — 5.00% more. 42 mm vs 40 mm.
Why Sony - ULT Wear 2 wins
- ▲Weight — 5.00 g less. 255 vs 260.
- ▲Has Active noise cancellation.
- ▲Has Multipoint.
- ▲Has LDAC.
- ▲Battery life: 50 h vs 0 h.
Spec comparison
Design
| Spec | Sennheiser - HD 660S2 | Sony - ULT Wear 2 |
|---|---|---|
| Type | over-ear | over-ear |
| Weight | 260 g | 255 glead |
| Water resistance | none | none |
Audio
| Spec | Sennheiser - HD 660S2 | Sony - ULT Wear 2 |
|---|---|---|
| Driver sizeⓘ | 42 mmlead | 40 mm |
| Impedanceⓘ | 300 Ωlead | 32 Ω |
| Sensitivityⓘ | 104 dBlead | 100 dB |
| Active noise cancellationⓘ | false | truelead |
| Transparency mode | false | truelead |
| Spatial audioⓘ | false | false |
Battery
| Spec | Sennheiser - HD 660S2 | Sony - ULT Wear 2 |
|---|---|---|
| Battery life | 0 h | 50 hlead |
| Fast chargeⓘ | false | truelead |
Connectivity
| Spec | Sennheiser - HD 660S2 | Sony - ULT Wear 2 |
|---|---|---|
| Bluetoothⓘ | 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 ULT Wear 2?+
ULT Wear 2 lasts 50 hours vs 0 hours.
Do HD 660S2 or ULT Wear 2 have active noise cancellation?+
ULT Wear 2 has ANC; HD 660S2 does not.
Which supports LDAC, HD 660S2 or ULT Wear 2?+
ULT Wear 2 supports LDAC; HD 660S2 does not.
Spec-level deep dives
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