Sennheiser HD 620S Uses an Angled 42mm Baffle and Steel Damping for Open-Style Staging in a Closed Chassis

For decades, the Sennheiser HD 600 and HD 650 have served as the default open-back reference headphones for home listeners, yet anyone sharing a living room or working in a quiet office quickly discovers how much sound leaks through open metal grilles. Closed-back studio headphones solve the isolation problem, though cup reflections often collapse the soundstage and cause mid-bass bloat. With the HD 620S ($349.95 MSRP, frequently available near $299.95), Sennheiser combines an angled 42mm transducer baffle with internal acoustic foam and steel cup covers to deliver panoramic staging inside a sealed enclosure.

Irish-Built 42mm Transducer & 150-Ohm Aluminum Voice Coil

Manufactured at Sennheiser’s Tullamore transducer facility in Ireland, the custom 42mm dynamic driver uses a 38mm laminate diaphragm driven by an ultra-lightweight 150-ohm aluminum voice coil. Keeping moving mass low improves impulse recovery and treble extension while maintaining total harmonic distortion below 0.05% (at 1 kHz, 90 dB SPL).

Rather than sealing the rear of the magnet assembly inside a tight plastic chamber, Sennheiser left the back of the transducer open inside a spacious earcup lined with acoustic absorber foam. A steel plate covering the outer shell acts as a rigid acoustic isolator that suppresses cup resonances while blocking outside room noise.

Angled Baffle Geometry & Balanced Cable Upgrade Path

Borrowing the roomy teardrop earcup shell from the HD 560S family, the HD 620S positions its transducers at a forward angle ahead of the ear canal. That geometry recreates the triangular acoustic perspective of a pair of nearfield monitors instead of placing vocals dead center inside your head.

Stainless-steel headband sliders add structural rigidity while keeping total weight down to 326 grams, and the supple artificial leather earpads feature internal perforations to dissipate heat. The single-sided twist-lock earcup jack accepts the included 1.8-meter 3.5mm cable (with a screw-on 6.35mm adapter) and is wired internally to support an optional 4.4mm balanced cable.

Sennheiser HD 620S Specifications

Specification	Details
Acoustic Principle	Closed-back circumaural (over-ear) with internal absorber and steel outer cup plate
Transducer	42 mm angled dynamic driver with 38 mm diaphragm
Voice Coil & Impedance	Ultra-lightweight aluminum voice coil; 150 Ω nominal
Frequency Response	6 Hz – 30,000 Hz
Sound Pressure Level (SPL)	110 dB (1 kHz / 1 Vrms) / 105 dB (1 kHz / 1 mW)
Total Harmonic Distortion	< 0.05% (1 kHz / 90 dB SPL)
Cable & Connector	1.8 m detachable single-sided cable with 3.5 mm plug & 6.35 mm screw-on adapter (4.4 mm balanced ready)
Weight	326 g (11.5 oz) without cable
MSRP	$349.95 USD