Sennheiser HD 660S2 - Audiophile Open-Back Headphones with Extended Bass

The **Sennheiser HD 660S2** is the legend, redefined. Experience the iconic HD 600 series precision now paired with a profoundly **extended sub-bass response** and a more intimate, moving soundstage. These **open-back over-ear headphones** are the ultimate choice for critical listening and pure musical enjoyment.

A Legend Reborn with Enhanced Low-End Power

The HD 660S2 takes the renowned clarity and natural timbre of the HD 600 family and introduces a game-changing **bass extension**. By optimizing the transducer's airflow and revising the voice coil, Sennheiser has doubled the sound pressure in the lowest frequencies, creating a deeper backdrop that makes the highs feel more brilliant and the soundstage more emotionally engaging. This results in a warmer, yet still highly detailed, sonic signature.

Engineered for the Audiophile

The HD 660S2 is designed for peak performance with dedicated headphone amplifiers. It features the classic **300 Ohm impedance** and an **ultra-light aluminum voice coil**, ensuring exceptionally clean impulse response and minimal distortion (THD <0.04%). This meticulous engineering provides superior precision, speed, and resolution, allowing you to hear every nuance of your favorite recordings.

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Key Features

• Extended Sub-Bass Response: Revised voice coil and surround for powerful, accurate bass down to 8 Hz.
• Audiophile-Grade Impedance: 300 Ohms for pristine performance when paired with quality headphone amplifiers.
• Open-Back Design: Delivers a natural, expansive, and non-fatiguing soundstage ideal for long listening sessions.
• Premium Comfort: Lightweight frame with comfortable, replaceable **velour earpads** for an excellent climate around the ears.
• High-Fidelity Drivers: 38mm dynamic transducers with a unique **vented magnet system** to minimize distortion.
• Versatile Connectivity: Includes both **unbalanced (6.3 mm)** and **balanced (4.4 mm)** cables to connect to a wide range of hi-fi equipment.

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Technical Specifications

Specification	Detail
Transducer Principle	Dynamic, Open-Back
Impedance	300 $\Omega$
Frequency Response	8 – 41,500 Hz
Sound Pressure Level (SPL)	104 dB (1 kHz, 1 Vrms)
Total Harmonic Distortion (THD)	< 0.04% (1 kHz, 100 dB)
Transducer Size	38 mm
Cable Length	1.8 m (x2)
Weight (w/o cable)	260 g (9.2 oz)

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Package Includes

The Sennheiser HD 660S2 comes with essential accessories for maximum compatibility with your audiophile setup:

• HD 660S2 Open-Back Headphones
• 1.8 m cable with **6.3 mm** (1/4") unbalanced stereo plug
• 1.8 m cable with **4.4 mm** balanced stereo plug
• Adapter from **6.3 mm to 3.5 mm** (1/8") stereo jack
• Soft Carry Pouch

Rediscover your music collection. Order the HD 660S2 today.