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This sennheiser HD 660s2 review focuses on a wired audiophile stereo headphone designed for high-fidelity listening. It features ultra-light aluminum voice coils and a 300-ohm impedance, which together deliver excellent impulse response and intimate sound with great timbre. The open-back design offers exceptional breathability, making it suitable for long sessions. With a frequency response ranging from 8 Hz to 41,500 Hz, it captures deep sub-bass and high frequencies. The 42mm transducers are airflow-optimized to minimize distortion. This model is built in Ireland and includes detachable cables for desktop use.
- Ultra-light aluminum voice coil with 300-ohm impedance for precise impulse response
- Airflow-optimized 42mm high-performance transducers with vented magnet system for minimal distortion
- Extended frequency response from 8 Hz to 41,500 Hz for deep sub-bass
- Open-back design with plush ear cushions for maximum comfort and breathability
Good fit for
You will likely enjoy these headphones if you are an audiophile seeking natural, relaxed sound with extra sub-bass. The 300-ohm impedance suggests you need a dedicated amplifier to drive them properly. The open-back design suits you if you listen in a quiet, controlled environment where sound leakage is not an issue. The exceptional comfort and build quality make it a strong choice for long listening sessions at your desktop. It fits users who value high-fidelity stereo imaging and detailed timbre over portability.
Who can skip it
You should look at another option if you need wireless connectivity, as this model is strictly wired. The 300-ohm impedance requires a powerful amplifier, so it is not ideal for direct connection to phones or laptops without additional gear. The open-back design means it lacks noise isolation, making it unsuitable for noisy commutes or open offices. If you prefer closed-back headphones for privacy or bass isolation, this model does not fit your needs. The detachable cable is a plus, but the lack of Bluetooth remains a constraint.
Verdict
The Sennheiser HD 660S2 is a high-fidelity wired headphone that excels in sound detail and comfort for dedicated listening setups. It is best suited for audiophiles with the necessary amplification and a quiet listening environment.
Key specs explained for HD 660S2
Impedance: 300-ohm
This resistance level requires more power than standard headphones. You will likely need a dedicated amplifier to drive them properly. Higher impedance allows for better control of the driver, resulting in cleaner sound. If you plug these into a phone, they will sound quiet. You need a desktop amp for full performance.
Frequency Response: 8 Hz – 41,500 Hz
This range covers deep bass down to ultra-high frequencies. The 8 Hz lower limit means you can feel sub-bass notes that are below human hearing. The 41,500 Hz upper limit captures extreme detail. This wide span ensures accurate reproduction of all instruments. It is ideal for critical listening where every nuance matters.
Transducer: 42mm high-performance
The driver size affects how much air the headphone moves. A 42mm transducer is standard for this class, balancing detail with impact. The vented magnet system reduces distortion. This size helps create a natural soundstage. You get precise imaging without the bulk of larger drivers. It suits those who want clarity in complex tracks.
Connection: Wired
This model uses a cable rather than Bluetooth. You avoid wireless compression and latency issues. The sound is direct and uncompressed. You must manage the cable length for your desk setup. This connection type is preferred by audiophiles for maximum fidelity. It eliminates the need for charging batteries.
Design: Open-back
The ear cups are not sealed, allowing air to flow through. This creates a natural, spacious soundstage that mimics speakers. You lose some noise isolation, so others can hear your music. It is best used in quiet rooms. The breathability keeps your ears cool during long sessions. It is not suitable for noisy environments.
Build and physical design
The Sennheiser HD 660S2 is a wired stereo headphone with a black finish. The listing describes the build as having exceptional quality, designed in Germany and made in Ireland. You get plush ear cushions that the manufacturer says deliver maximum comfort for long listening sessions. The open-back design is noted for its breathability, which helps keep your ears cool during extended use.
In terms of physical dimensions, the listing provides specific measurements. The headphones measure 7 inches in width and 7 inches in height. The length is listed as 3 inches. The size is categorized as medium. The color is black. These dimensions suggest a standard over-ear form factor that sits comfortably on the head without excessive bulk. The medium size likely fits most adult head sizes without needing extensive adjustment.
The connection type is wired, which means there are no batteries or wireless components to manage. The listing mentions detachable, long cables for comfortable desktop use. This layout suits stationary environments like a home studio or office desk. You do not need to worry about charging or signal interference. The build focuses on durability and acoustic performance rather than portability. The materials and design choices indicate a product intended for serious listening at a fixed location, prioritizing sound fidelity and comfort over mobile convenience.
Setup and everyday use
Setting up the Sennheiser HD 660S2 requires a specific audio chain. The 300-ohm impedance means these headphones will not sound right when plugged directly into a phone or laptop. You need a dedicated amplifier to drive the ultra-light aluminum voice coils properly. Without sufficient power, the sound will feel thin and lack the deep sub bass the specs promise. The connection is wired, so you will manage a long detachable cable. This setup is ideal for a stationary desktop environment. The open-back design affects how you use them daily. Because sound escapes from the back, these headphones are not for public use. They offer exceptional breathability, which keeps your ears cool during long sessions. The plush ear cushions are designed for maximum comfort, allowing you to wear them for hours without pressure. The transducers are optimized for airflow, reducing distortion even at high volumes. You can expect to hear the lowest octaves, like a piano’s lowest note or a kick drum, with clarity. The frequency response extends to 41,500 Hz, capturing details beyond standard hearing ranges. This makes them suitable for critical listening in a quiet room. The build is sturdy, designed in Germany and made in Ireland. You will handle the detachable cable carefully to ensure a secure connection. The medium size fits most head shapes. The black finish blends into most home studios. This is a serious tool for audiophiles who prioritize fidelity over convenience. You must invest in good amplification to get the best results from this hardware.
Before you buy HD 660S2
You must verify your audio chain before purchasing these wired headphones. The 300-ohm impedance requires a dedicated amplifier to produce proper volume and clarity. Plugging them directly into a computer or phone will result in weak sound. You also need to check your desk space. The dimensions are seven inches wide and seven inches tall. These are open-back models. This design allows sound to escape, so they are not suitable for shared offices or noisy environments. You will hear surrounding noise, and others will hear your music. Keep the plush ear cushions clean. Dust and oils can degrade the material over time. Store the detachable cable carefully to prevent fraying. When comparing this to other options in the 1 Headphones list, note that this model prioritizes natural timbre and deep sub-bass. It suits listeners who value accuracy over isolation. If you need wireless convenience or noise cancellation, look elsewhere. This product is built for critical listening at home.
Check before you buy
- Confirm you have a powerful headphone amplifier for the 300-ohm impedance.
- Ensure your listening environment is quiet enough for open-back leakage.
- Check that your desk has space for the seven-inch width.
- Verify you prefer wired connections over wireless convenience.
- Accept that these headphones do not block outside noise.
Sennheiser HD 660S2 Open-Back Headphones
Best for: critical listening with dedicated amplifiers
- Connectivity
- Wired
- Use
- Audiophiles
- Color
- Black
- Ear Style
- Stereo
- Dimensions
- 3 × 7 × 7 inches
The Sennheiser HD 660S2 is a wired, open-back stereo headphone built for audiophiles. It features 300-ohm impedance and ultra-light aluminum voice coils for high-fidelity sound. The 42mm transducers offer a frequency response from 8 Hz to 41,500 Hz. Its open design ensures breathability during long sessions. You get a relaxed, detailed audio experience with deep sub-bass extension.
- 300-ohm impedance for excellent impulse response
- Ultra-light aluminum voice coil for high fidelity
- 42mm transducers with 8 Hz to 41,500 Hz range
- Open-back design for exceptional breathability
- Detachable cables for desktop convenience
- 300-ohm impedance requires a dedicated amplifier
- Open-back design offers no noise isolation
- Wired connection limits mobility
- You want detailed, high-fidelity sound for critical listening
- You use a dedicated headphone amplifier
- You prefer open-back headphones for a natural soundstage
- You need wireless connectivity for mobile use
- You require noise isolation in loud environments
- You plan to drive headphones directly from a phone
Verdict: Sennheiser HD 660S2 Wired Open-Back suits listeners seeking detailed audio who have the necessary amplifier gear. It is ideal for home studio or desktop listening where sound quality matters most.
Specifications side by side
| Spec | Sennheiser HD 660S2 Open-Back Headphones |
|---|---|
| Connectivity | Wired |
| Connection | Wired |
| Use | Audiophiles |
| Color | Black |
| Ear Style | Stereo |
| Dimensions | 3 × 7 × 7 inches |
| Size | Medium |
| Model | HD 660S2 |
Frequently asked questions
Are these headphones good for gaming?
The Sennheiser HD 660S2 is designed for critical listening, not gaming. Its open-back design lacks the sound isolation needed for competitive play. The wide soundstage offers excellent imaging for music, but it does not provide the focused, enclosed audio typical of gaming headsets. You should choose a closed-back model for gaming.
Do I need an amplifier for the HD 660S2?
Yes, you need a dedicated amplifier. The 300-ohm impedance requires more power than standard devices provide. Plugging them directly into a phone or laptop will result in weak sound. A dedicated amp ensures the ultra-light aluminum voice coils perform correctly, delivering the intended clarity and detail.
What is the fit like for large ears?
The headphones are medium-sized, measuring 7 by 7 by 3 inches. They feature plush ear cushions designed for maximum comfort during long sessions. The open-back design also improves breathability. If you have very large ears, check the physical dimensions against your current headphones to ensure a proper seal.
Can I use these for studio monitoring?
These are ideal for home studio or desktop listening where sound quality matters most. The wired connection ensures no latency, and the detailed audio reproduction suits critical work. However, the open-back design allows sound leakage. You should use them in a quiet room rather than a noisy shared space.
Are these wireless headphones?
No, the Sennheiser HD 660S2 are wired headphones. They do not support Bluetooth or wireless connectivity. This wired design eliminates battery concerns and potential signal interference. You must connect them directly to your audio source or amplifier using the included cable for consistent, high-fidelity audio transmission.
How durable is the build quality?
The listing describes the build as having exceptional quality. Designed in Germany and made in Ireland, the construction focuses on longevity. The black finish and sturdy materials suggest a professional-grade device. The aluminum voice coils are noted for their durability and precise movement, contributing to the headphone's long-term performance.
Is the soundstage wide or narrow?
The open-back design offers a wide soundstage. This creates an intimate sound with great timbre and excellent impulse response. You will hear instruments and vocals as if they are spread out in space. This separation is beneficial for classical music and detailed acoustic tracks, providing a more natural listening experience.