Sennheiser HD 660S2 vs Sony ULT Wear
The Verdict
Sennheiser's HD 660S2 targets serious audiophiles with its open-back design, 300-ohm impedance, and handmade German craftsmanship, requiring a dedicated amplifier for optimal performance. Sony's ULT Wear delivers versatile wireless convenience at less than half the price, featuring 30-hour ANC battery life, LDAC hi-res codec support, multipoint pairing, and ULT bass enhancement for portable listening. Sound character differs fundamentally: the Sennheiser excels in analytical detail and soundstage through passive design, while Sony prioritizes comfort and feature richness for everyday use. Battery life, wireless connectivity, and adaptive features heavily favor Sony, though the Sennheiser rewards critical listeners with superior transducer quality when properly amplified. Choose the HD 660S2 if you have a quality amp and value pure audio fidelity; select the ULT Wear for balanced performance, wireless flexibility, and excellent value in a practical package.
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 ULT Wear if…
- →ULT bass button adds two levels of genuinely impactful bass boost
- →50-hour battery without ANC is industry-leading endurance
- →LDAC hi-res audio and multipoint at just $199 is outstanding value
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 ULT Wear
Pros
- ULT bass button adds two levels of genuinely impactful bass boost
- 50-hour battery without ANC is industry-leading endurance
- LDAC hi-res audio and multipoint at just $199 is outstanding value
- Effective ANC that rivals headphones at twice the price
- Sony's proven comfort and lightweight design
Cons
- ULT bass mode can overwhelm mids and treble at max setting
- No IP rating — not suitable for gym or outdoor use
- Bluetooth 5.2 instead of newer 5.3
- Plastic build feels less premium than XM5
Full Specifications
| Spec | Sennheiser HD 660S2 | Sony ULT Wear |
|---|---|---|
| Active Noise Cancelling | ||
| Type | over-ear | over-ear |
| Weight | 260 g | 255 g |
| Battery | ||
| Battery life | N/A (wired) | 30 hrs (ANC on), 50 hrs (ANC off) |
| Charging | N/A | USB-C, 10-min quick charge for 5 hrs |
| Drivers | 42mm dynamic transducer, 300 ohm impedance | 40 mm |
| 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 | ULT button for extra bass — two bass boost levels, Adaptive Sound Control, LDAC hi-res audio, Multipoint Bluetooth pairing, Speak-to-Chat auto-pause, 360 Reality Audio |
| Connectivity | ||
| Wired option | ||
| Codecs | LDAC, AAC, SBC | |
| 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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