Sennheiser x Massdrop HD 6XX Open-Back Wired Headphones
 
Audiophile open-back Sennheiser headphones with a natural, detailed sound for music listening, mixing, desktop audio, and headphone amp setup
The Sennheiser x Massdrop HD 6XX is a well-known open-back over-ear headphone based closely on the classic HD 650 sound profile, offering smooth mids, clear detail, and a spacious open presentation. These are ideal for home listening, studio-style monitoring, gaming at a desk, or anyone building a proper wired headphone setup.
This pair has been tested and is working properly with no audio issues. The headphones include the attached cable and the 1/4" adapter shown in the photos, making them easy to connect to audio interfaces, headphone amps, receivers, and other gear with a full-size headphone output.
 
Condition:
Good used physical condition with normal cosmetic wear from previous use. The outside of the earcups shows some minor scuffs and handling marks, as shown in the photos. The headband, hinges, grilles, cable, and ear pads are intact, with normal lint/wear on the velour-style pads from use.
No working issues. Audio plays properly from both sides, and the headphones are ready to use.
 
Includes:
Sennheiser x Massdrop HD 6XX Headphones: Tested and working
Attached headphone cable: 3.5mm connection
1/4" adapter: Included as shown in the photos
Not Included: No box, case, manuals, extra cables, amp/DAC, stand, or additional accessories
 
Key Features:
Open-Back Audiophile Design: Gives a wider, more natural soundstage than closed-back headphones, ideal for quiet home or studio use.
Over-Ear Fit: Large circumaural earcups sit around the ears for comfortable extended listening.
Dynamic Drivers: Smooth, detailed Sennheiser sound with strong midrange clarity and a balanced presentation.
300 Ohm Impedance: Best matched with a headphone amp, audio interface, receiver, or stronger desktop output.
10 Hz – 41 kHz Frequency Response: Wide published response range for detailed music playback.
Detachable-Style Sennheiser Cable System: Uses the familiar dual-cup Sennheiser cable layout.
3.5mm Plug with 1/4" Adapter: Works with standard headphone outputs and larger studio/audio gear outputs.
Lightweight Build: Approx. 260g without cable, comfortable for longer listening sessions.
Velour-Style Ear Pads: Soft over-ear pads designed for comfort and breathability.
Massdrop Collaboration Model: Popular HD 6XX edition made in collaboration with Sennheiser.
 
Frequently Asked Questions:
Q: Are these tested?
A: Yes. They have been tested and are working with no audio issues.
Q: What is included?
A: The headphones, attached cable, and the 1/4" adapter shown in the photos.
Q: Is the box included?
A: No. No box, case, manuals, or extra accessories are included.
Q: Are these wireless?
A: No. These are wired open-back headphones.
Q: Do they need an amp?
A: They can work from some headphone outputs, but because they are 300 ohms, they perform best with a headphone amp, audio interface, receiver, or stronger desktop source.
Q: Are they good for travel or noisy rooms?
A: No. These are open-back headphones, so they leak sound and do not block outside noise well. They are best for quiet home or studio use.