Sennheiser HD 660S2 Review: Audiophile Gaming Headphone Worth It?

Let’s cut right to it: most “gaming headsets” are garbage. They slap some RGB on a plasticky frame, throw in a mediocre mic, and call it a day. But what if you’re serious about sound? What if you want the pinpoint accuracy for competitive play and the rich, detailed audio for your music library, all without compromising? That’s where you start looking beyond the gaming aisle and into the audiophile world.

The Sennheiser HD 660S2 isn’t a gaming headset by design, but it’s quickly becoming a darling among power users who understand that good audio transcends marketing labels. This headphone aims to refine an already legendary sound profile, promising improvements where the previous iteration (and even its older siblings) might have left some wanting. We’re talking about a serious piece of kit for serious listeners, whether they’re tracking footsteps in Valorant or dissecting a new album.

What is Sennheiser HD 660S2?

The Sennheiser HD 660S2 is an open-back, dynamic driver headphone, serving as the latest iteration in Sennheiser’s highly respected 600-series lineage. It’s designed for critical listening, mixing, mastering, and, increasingly, for those who demand uncompromising audio fidelity in their gaming sessions. Unlike typical closed-back gaming headsets, its open design means sound can pass in and out freely, leading to a more natural, spacious soundstage and preventing pressure build-up.

This model is built with a high 300-ohm impedance, which is a clear signal that it’s not meant to be plugged directly into a phone or console controller. It requires a dedicated headphone amplifier to drive it properly, unlocking its full dynamic range and detail retrieval. Think of it as a high-performance sports car: it needs premium fuel and a skilled driver to truly shine.

Key features

The HD 660S2 packs several refinements that distinguish it from its predecessors and other headphones in its class. These aren’t just marketing bullet points; they’re tangible changes that affect the listening experience.

• Improved Bass Response: Sennheiser specifically re-tuned the S2 to offer a more impactful and extended bass presence, addressing a common critique of the original HD 660S and the HD 600 series’ characteristic leaner low end.
• 300-Ohm Impedance: While requiring an amp, this high impedance ensures excellent damping factor control and allows the drivers to operate with minimal distortion, contributing to a cleaner, more precise sound.
• Open-Back Design: The earcups are open, creating an airy, natural soundstage that reduces listening fatigue and enhances spatial awareness, crucial for immersion and competitive advantage.
• Detachable Cables: Features a standard 2-pin connector (compatible with many aftermarket cables), allowing for easy replacement or upgrading to balanced cables. Includes both 6.3mm and 4.4mm balanced cables in the box.
• Comfort-Focused Ergonomics: Utilizes the classic Sennheiser 600-series lightweight frame and plush velour earpads, ensuring excellent comfort even during marathon listening or gaming sessions.
• Hand-Selected Drivers: Each driver is meticulously matched during manufacturing to ensure consistent channel balance and optimal acoustic performance across both earcups.
• Made in Ireland: Continues Sennheiser’s tradition of European manufacturing for its premium headphones, often associated with higher quality control standards.

How it actually performs

Let’s get down to the brass tacks: what’s it like to actually use the HD 660S2? This isn’t a headphone you just plug in and forget. Its performance is directly tied to the quality of your source chain.

First, the bass. Sennheiser claims an improved bass response, and in my testing, they absolutely delivered. This isn’t a bass-head’s dream, but it’s a significant upgrade over the original 660S. Kicks in music now have more authority, and explosions in games like Battlefield 2042 hit with a satisfying thud rather than a polite cough. The sub-bass extension is noticeably better, allowing you to feel the rumble in cinematic moments or the low-end presence of ambient game soundtracks. It’s articulate, too, not just a muddy blob.

When it comes to detail retrieval and imaging, the HD 660S2 shines. In Apex Legends, I could consistently pinpoint enemy footsteps and ability activations with startling accuracy. The separation of sounds is excellent; even in chaotic team fights, individual sound elements like gunshots, healing, and voice lines remain distinct. This level of clarity translates directly into a competitive edge, allowing for quicker reaction times based on auditory cues. This is a headphone that rewards careful listening.

The soundstage, while open and natural, isn’t the widest you’ll find. It’s an intimate presentation, placing you “in the room” with the music or “on the battlefield” rather than giving you a vast, cavernous sense of space. Think of it more like a focused spotlight than a floodlight. For gaming, this isn’t necessarily a bad thing; a tightly rendered soundstage with precise imaging can be more useful than an overly diffuse one for competitive play. For example, in CS:GO, you’re not trying to hear someone across the map, you’re trying to hear them around the corner, and the 660S2 excels at that specific task.

Comfort is another area where the 600-series design truly excels. The lightweight plastic build, combined with the plush velour pads and moderate clamping force, means I can wear these for 4-5 hour gaming sessions without any discomfort. My ears never felt hot or sweaty, a common issue with pleather pads found on many gaming headsets. The build quality feels solid, despite the plastic, and the removable cables mean longevity isn’t a concern.

One critical point: an amplifier is non-negotiable. Trying to run these off a motherboard’s audio jack or a standard console controller will result in a thin, lifeless sound with insufficient volume. A good entry-level DAC/amp combo like the Schiit Magni/Modi stack or the FiiO K5 Pro ESS is almost mandatory to truly experience what the HD 660S2 has to offer. Without it, you’re not getting your money’s worth.

Pricing breakdown

The Sennheiser HD 660S2 positions itself firmly in the mid-to-high end of the audiophile headphone market. It’s not a budget option, nor is it stratospherically priced like some planar magnetics.

Tier	Product	Price (Approx.)	Who it’s for
Premium	Sennheiser HD 660S2	$599	Audiophiles and serious gamers seeking a refined, musical, and detailed experience.
Mid-Range	Sennheiser HD 600	$399	Entry-level audiophiles, studio engineers, and those preferring a neutral sound.
Budget	Sennheiser HD 560S	$199	Gamers and casual listeners wanting open-back sound without high impedance.

The $599 price tag for the HD 660S2 represents an investment. It’s for the buyer who has likely already dipped their toes into better audio and understands the value of a quality transducer. It’s priced above the classic HD 600 and HD 650, reflecting its updated tuning and inclusion of balanced cables.

Considering the necessary amplifier, the total cost of entry will likely be in the $750-$1000 range, depending on your chosen DAC/amp. This needs to be factored into your decision. While it might seem steep, this setup provides a level of audio fidelity far beyond any all-in-one gaming headset. If you’re looking for where to buy, you can often find good deals from authorized retailers.

Who should use Sennheiser HD 660S2?

This headphone is for the dedicated gamer who takes audio seriously and understands its impact on performance and immersion. If you frequently play competitive FPS games where sound cues are vital, the HD 660S2’s imaging and detail will be a significant advantage. It’s also ideal for audiophiles who appreciate a natural, slightly warm, and detailed sound signature that excels across various music genres. If you prioritize comfort for long listening sessions and appreciate solid build quality, the S2 is a strong contender.

Explicitly, who shouldn’t use the HD 660S2? If you’re on a tight budget and can’t afford a dedicated amplifier, this isn’t for you. It’s also not for bass heads who want earth-shattering rumble; while improved, the bass is still refined and articulate, not overbearing. If you require a built-in microphone or a closed-back design for noise isolation (e.g., in a noisy environment), look elsewhere. Finally, if you’re expecting an enormous, concert-hall-like soundstage, some other open-back options might better suit that specific preference.

HD 660S2 vs HD 600: Is the HD 660S2 worth it?

This is the million-dollar question for many Sennheiser fans. The HD 600 is a legend, known for its neutral, analytical, and slightly dry sound. The HD 660S2 takes that foundation and injects a shot of warmth and dynamism. The most significant difference is in the low-end: the 660S2 has a more prominent and extended sub-bass and mid-bass, making music feel more engaging and games more impactful. The soundstage also feels a touch wider and deeper on the S2, though still not expansive.

Is it worth the extra $200 over the HD 600? If you find the HD 600 too lean in the bass or a bit too analytical for casual listening and gaming, then absolutely. The 660S2 offers a more “fun” yet still highly resolving sound. If you already own an HD 600 and are perfectly happy with its linearity, the upgrade might be less compelling unless you specifically crave that extra bass. However, if you’re buying new and want the most modern, engaging sound from Sennheiser’s 600 series, the HD 660S2 is the clear winner for its refined tuning.

Alternatives worth considering

While the HD 660S2 is a fantastic headphone, it’s not the only fish in the sea. Here are a couple of strong alternatives:

• Sennheiser HD 600: The classic neutral reference. If you prefer a flatter, more analytical sound for mixing or critical listening, the HD 600 remains an excellent, more affordable choice.
• Hifiman Sundara: A planar magnetic alternative that offers a significantly wider soundstage and often superior bass extension and texture, though it can be more difficult to drive and some find its treble a bit brighter.
• Beyerdynamic DT 900 PRO X: A slightly more affordable open-back that doesn’t require as much power. It offers excellent detail and a more V-shaped sound signature, but its soundstage and imaging aren’t quite as pinpoint as the 660S2.

Final verdict

The Sennheiser HD 660S2 is an impressive headphone that successfully refines a beloved sound signature. It’s a confident step forward, bringing more bass presence and a slightly more engaging sound while retaining the core Sennheiser strengths of natural timbre, excellent detail, and supreme comfort. For the serious gamer or audiophile who understands the necessity of a proper amplification setup, the HD 660S2 delivers an outstanding audio experience that easily transcends the limitations of dedicated “gaming” peripherals.

It’s not a budget option, and it demands the right gear to shine, but for those willing to invest, it provides a compelling blend of musicality and competitive performance. If you want a headphone that will serve you equally well tracking enemies and enjoying your favorite albums for years to come, the HD 660S2 is absolutely worth considering.

Rating: 4.2 / 5.0