Sennheiser HD 660S2 vs Sony WH-CH720N
The Verdict
Sennheiser HD 660S2 and Sony WH-CH720N serve entirely different audiophile needs. Sennheiser's wired-only, open-back design features a premium 42mm driver with 300-ohm impedance, requiring a dedicated amplifier and DAC for optimal performance. Handmade in Germany with replaceable components, it's built for critical listening in controlled environments. Sony's WH-CH720N prioritizes versatility with active noise cancellation, Bluetooth 5.2 multipoint connectivity, and exceptional 35-hour battery life. Its LDAC codec and DSEE upscaling provide respectable wireless audio quality, while Adaptive Sound Control and Speak-to-Chat enhance daily usability. At $149, the Sony delivers wireless convenience and ANC technology impossible at that price point. However, Sennheiser's $499 investment rewards dedicated audiophiles with superior sound staging and clarity that wireless compression cannot match. Choose Sony for portable, practical noise-canceling daily use; select Sennheiser for stationary, studio-quality listening with hi-fi equipment.
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 WH-CH720N if…
- →Exceptional 35-hour battery life with ANC is class-leading
- →Ultra-lightweight at 192 g for comfortable all-day wear
- →LDAC codec support for high-resolution wireless audio
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 WH-CH720N
Pros
- Exceptional 35-hour battery life with ANC is class-leading
- Ultra-lightweight at 192 g for comfortable all-day wear
- LDAC codec support for high-resolution wireless audio
- Multipoint Bluetooth for seamless dual-device switching
- Solid noise cancellation at a very competitive $149 price
Cons
- ANC is noticeably weaker than premium XM5 headphones
- 30mm drivers produce smaller, less dynamic soundstage
- Plastic build feels cheap compared to premium Sony models
- No water resistance for gym or outdoor use
- Ear cushions are thinner and less comfortable than XM5
Full Specifications
| Spec | Sennheiser HD 660S2 | Sony WH-CH720N |
|---|---|---|
| Active Noise Cancelling | ||
| Type | over-ear | over-ear |
| Weight | 260 g | 192 g |
| Battery | ||
| Battery life | N/A (wired) | 35 hrs (ANC on), 50 hrs (ANC off), 3 min = 1 hr playback |
| Charging | N/A | USB-C |
| Drivers | 42mm dynamic transducer, 300 ohm impedance | 30mm |
| 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 | Adaptive Sound Control, Speak-to-Chat automatic pause, DSEE upscaling for compressed audio, Multipoint Bluetooth, Sony Headphones Connect app with EQ |
| Connectivity | ||
| Wired option | ||
| Codecs | AAC, SBC, LDAC | |
| Bluetooth | None (wired only) | 5.2 |
| Multipoint | ||
| Water Resistance | None | None |
Related Comparisons
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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