Sennheiser HD 650 – Over Ear Open Back Wired Headphones

Sennheiser HD 650 – Over Ear Open Back Wired Headphones

The Sennheiser HD 650 is an open-back, dynamic hi-fi stereo headphone designed for home use with high-quality audio systems. It features an exclusive 42 mm transducer with a 38 mm diaphragm and lightweight aluminum voice coil, paired with a special damping element made from fine acoustic metal mesh. Each unit is hand-picked in pairs with tight production tolerances of ± 1 dB for consistent left and right channel matching across the frequency spectrum.

• Wired, over-ear, open-back dynamic headphone
• 42 mm transducer with 38 mm diaphragm and lightweight aluminum voice coil
• Frequency response: 10 – 41,000 Hz (–10 dB)
• Impedance: 300 Ω
• Detachable OFC copper cable (3 m) with 1/4" (6.35 mm) stereo jack connector and included 3.5 mm adapter
• Weight: 260 g (without cable)
• Made in Ireland
• 2 Year Warranty

Highlights & Key Technologies

Transducer & Acoustic Design
The HD 650 uses an exclusive 42 mm transducer with a 38 mm diaphragm driven by an extremely lightweight aluminum voice coil for excellent transient response and impulse accuracy. A specially developed acoustic metal mesh serves as the damping element, providing precise and uniform attenuation over the entire diaphragm surface. The open-back circumaural design allows soundwaves to expand naturally, and the diffuse-field equalized frequency characteristic delivers a response from 10 Hz to 41,000 Hz. Each transducer is manufactured against rigid specifications and hand-picked in pairs with tolerances of ± 1 dB, ensuring consistent representation of the frequency spectrum in both left and right channels.

Cable & Connectivity
The HD 650 includes a detachable 3-meter connection cable made from highly conductive oxygen-free copper (OFC), reinforced with para-aramid fibers for high tensile strength and low handling noise. The cable terminates in a 1/4" (6.35 mm) stereo jack plug, with an included adapter reducing to 3.5 mm for connection to a wider range of audio devices. The HD 650 can be directly connected to high-quality stationary hi-fi components, including SACD, DVD-A, Blu-ray, and CD players, as well as DACs for Mac or PC for high-resolution music files. Optional balanced connection cables are available: the Sennheiser CH 660 P with 4.4 mm stereo jack plug and the CH 650 S with XLR-4 connector, both compatible with the Sennheiser HDV 820 balanced headphone amplifier.

Comfort & Construction
The HD 650 features an elliptical ear cup design adapted to the shape of the ear for circumaural (over-ear) fit. Velour ear pads provide extended listening comfort, and both the ear pads and connection cable are user-replaceable. The headband padding is replaceable through the manufacturer's repair service. The high-quality titanium silver finish and modular component design support long-term use and serviceability. The HD 650 is manufactured in Ireland.

Details & Specifications

MODEL INFORMATION
Model: HD 650
Article number (SKU): 508825

TRANSDUCER
Transducer principle: Dynamic
Transducer size: 42 mm
Diaphragm size: 38 mm
Voice coil material: Aluminum
Acoustic design: Open-back
Ear coupling: Circumaural
Frequency characteristic: Diffuse-field equalized
Magnetic field strength at surface: 1.8 mT

PERFORMANCE
Frequency response: 10 – 41,000 Hz (–10 dB)
Nominal impedance: 300 Ω
Sound pressure level: 103 dB (1 Vrms at 1 kHz)
Total harmonic distortion: ≤ 0.05% (1 kHz, 1 Vrms)
Long-term input power: Max 500 mW (per EN 60-268-7)

CABLE & CONNECTIVITY
Included cable: Oxygen-free copper (OFC) with para-aramid fiber reinforcement, 3 m
Connector: 1/4" (6.35 mm) stereo jack plug
Included adapter: 1/4" (6.35 mm) to 3.5 mm stereo jack plug
Optional balanced cables: 4.4 mm stereo jack (CH 660 P), XLR-4 (CH 650 S)

PHYSICAL SPECIFICATIONS
Weight: Approximately 260 g (without cable)
Contact pressure: Approximately 6.0 N ± 1.0 N
Finish: Titanium silver
Ear pads: Velour, user-replaceable

ENVIRONMENTAL
Operating temperature: –10°C to +55°C

INCLUDED ACCESSORIES
Sennheiser HD 650 open-back dynamic headphones
Connection cable with 1/4" (6.35 mm) stereo jack plug, 3 m
Stereo jack adapter (1/4" / 6.35 mm to 3.5 mm)
Instruction manual