Sennheiser HD 660S2 700240

The HD 660S2 brings best-in-class build quality and wonderfully natural sound that's a step above most in its bracket. But you'll need a good DAC/amp, and the narrow soundstage and abysmal mic hold it back. A fantastic buy at around $400-500 for serious listeners, but not a wise pickup if you want all-around versatility.

The audio performance is where the HD 660S2 shines, landing in the 81st percentile overall. You get deep, controlled bass that reaches down to 9Hz on paper, and the mids deliver vocals with a lifelike presence that's genuinely arresting. The highs are precise without being harsh. But the soundstage, while spacious in an open-back sense, feels narrower than some expect for critical listening. It's not a wide, airy presentation, more intimate. Also, don't even think about the mic, it's a letdown at the 16th percentile, so calls are a no-go. You'll need a dedicated mic if you're streaming or chatting.

Compared to wireless flagships like the Sony WH-1000XM6 or Bose QuietComfort Ultra, the HD 660S2 lives in a different world. Those are packed with ANC, Bluetooth, and mics for calls, while the 660S2 is a purist's wired headphone that demands a quiet room and a good amp. Newer entries like the Sennheiser MOMENTUM M5AEBT, Sony ULT WEAR WHULT900N/B, JBL Tune 670NC, and Bose QuietComfort 884367-1100 all bring modern features and solid sound for far less hassle, but they can't match the raw, uncolored detail these open-backs provide when properly driven. If you're serious about sound and don't mind the wires, the Sennheisers are a standout, especially for studio monitoring where accuracy trumps convenience.

Is it worth the money? That depends entirely on what you pay. The price spread is wild—$417 to over $91,000—which feels like a data glitch, but even at the real-world low end, you're competing with excellent alternatives. If you can scoop them up from a vendor offering a solid discount, the value is strong for a dedicated music and studio tool. But at full MSRP, the plasticky touches and narrow staging make it a tougher sell when you could snag something like a B&W Px8 S2 for wireless flexibility or even the Sennheiser HD 600 for a fraction of the cost.

Look, the Sennheiser HD 660S2 isn't for the casual listener. These are open-back, wired headphones with a 300Ω impedance that practically demands a solid DAC/amp combo to wake them up. But if you've got the gear, they reward you with a natural, detailed sound that's among the best at this price when you hunt down a deal. They feel more like a precision tool than a plug-and-play accessory. And the pricing is all over the map, from $417 to a baffling $91,845 across vendors. So if you're patient and find them under $500, the value proposition shifts dramatically. Just know what you're signing up for: a stationary listening experience that doesn't travel well and falls apart for calls and gaming with friends.

If you need headphones that can double as a gaming headset, handle phone calls, or block out airplane noise, skip these entirely. They're also a bad fit if you don't already own a decent headphone amp or aren't willing to buy one. And if you prize a huge, airy soundstage for classical or live recordings, the HD 660S2's narrower presentation might leave you disappointed. Look at the Beyerdynamic DT 1990 Pro or HiFiMan Sundara for wider staging in this price tier.

These are for the audiophile who knows exactly what they're getting into: a high-impedance, open-back headphone that will sit on your desk tethered to an amp. If you're a musician, mixer, or just someone who loves picking apart a recording, the HD 660S2 delivers fantastic clarity and timbre. Casual listeners, gamers needing a headset, or anyone who wants ANC and portability should look elsewhere. They're a niche product that nails that niche.