Sennheiser HD 660S2 vs Sony WF-1000XM4
The Verdict
These headphones target fundamentally different use cases despite overlapping price points. Sennheiser's HD 660S2 is a wired, open-back audiophile reference monitor designed for critical listening at a desk with a dedicated amplifier, featuring a 42mm driver and demanding 300-ohm impedance that requires proper source equipment to shine. Sony's WF-1000XM4 are wireless earbuds optimized for active lifestyle use, delivering excellent noise cancellation, 8-12 hours of battery life depending on ANC settings, and LDAC codec support for wireless Hi-Res Audio playback. The Sennheiser excels in soundstage, clarity, and detail retrieval for studio work and music production but demands a $200-500 amplifier investment to reach its potential and provides zero portability. Sony prioritizes convenience with multipoint connectivity, fast charging (5 minutes yields 1 hour playback), IPX4 water resistance, and industry-leading ANC that adapts to your environment in real time. Sound quality favors the HD 660S2 for critical listening, while Sony wins decisively for everyday versatility. Budget matters significantly here: Sony's $279 price includes complete functionality out of the box, whereas the Sennheiser at $499 demands additional investment. Choose the HD 660S2 if you're an audiophile with proper amplification setup; choose Sony for portable, feature-rich listening across commuting, workouts, and casual use.
Who Should Buy
Buy the Sennheiser HD 660S2 if…
- →Reference-grade sound with improved bass over the original HD 660S
- →Both 6.35mm and 4.4mm balanced cables included in the box
- →Open-back design creates a wide, natural soundstage
Buy the Sony WF-1000XM4 if…
- →Industry-leading ANC in a true wireless form factor at launch
- →LDAC support enables Hi-Res wireless audio streaming
- →8-hour battery with ANC is strong for true wireless earbuds
Category Scores
Pros & Cons
Sennheiser HD 660S2
Pros
- Reference-grade sound with improved bass over the original HD 660S
- Both 6.35mm and 4.4mm balanced cables included in the box
- Open-back design creates a wide, natural soundstage
- Lightweight at 260 g for an audiophile over-ear
- Replaceable parts make it a long-term investment
Cons
- 300-ohm impedance requires a dedicated amp/DAC to drive properly
- Wired only — no Bluetooth option
- Open-back leaks significant sound — not for shared spaces
- $499 is steep for headphones that need additional equipment
Sony WF-1000XM4
Pros
- Industry-leading ANC in a true wireless form factor at launch
- LDAC support enables Hi-Res wireless audio streaming
- 8-hour battery with ANC is strong for true wireless earbuds
- Speak-to-Chat pauses audio when you start talking
- Foam ear tips provide excellent passive noise isolation
Cons
- Foam ear tips degrade over time and need replacement
- IPX4 is basic splash resistance — not suitable for heavy sweat
- At 7.3 g per earbud they are slightly heavier than competitors
- Charging case is bulky compared to AirPods Pro
- Touch controls can be oversensitive on the small surface area
Full Specifications
| Spec | Sennheiser HD 660S2 | Sony WF-1000XM4 |
|---|---|---|
| Active Noise Cancelling | ||
| Type | over-ear | in-ear |
| Weight | 260 g | 7.3 g (each) |
| Battery | ||
| Battery life | N/A (wired) | 8 hrs (ANC on), 12 hrs (ANC off), 24 hrs total with case |
| Charging | N/A | USB-C, Qi wireless, 5 min = 1 hr playback |
| Drivers | 42mm dynamic transducer, 300 ohm impedance | 6mm dynamic driver |
| Features | Open-back audiophile design, 300-ohm impedance for dedicated amp/DAC use, Balanced 4.4mm Pentaconn cable included, Replaceable ear pads and cables, Handmade in Germany | Integrated Processor V1 for ANC and audio, LDAC for Hi-Res Audio wireless, Speak-to-Chat automatic pause, Adaptive Sound Control, 360 Reality Audio, Sony Headphones Connect app |
| Connectivity | ||
| Wired option | ||
| Codecs | AAC, SBC, LDAC | |
| Bluetooth | None (wired only) | 5.2 |
| Multipoint | ||
| Water Resistance | None | IPX4 |
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This comparison is based on verified manufacturer specifications covering display, performance, camera, battery, and build quality. Scores are generated by analyzing specs across weighted categories on a 10-point scale. Learn more about our methodology.
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