Over-Ear Headphones · owner-verdict comparison

Bose QuietComfort Ultra Headphones (2nd Gen) vs Sennheiser HD 660S2: what real owners say

Real owners lean toward the Sennheiser HD 660S2: 61% of 231 owners recommend it, vs 35% of 474 for the Bose QuietComfort Ultra Headphones (2nd Gen).

Verdicts aggregated from Reddit, enthusiast forums, and YouTube owner comments — affiliate reviews excluded. Sample sizes differ; judge accordingly. How we score

Bose QuietComfort Ultra Headphones (2nd Gen)

35%of 474 owners recommend

35% recommend · 23% neutral · 42% don't

Owners praise

Exceptional comfort for long sessions, owners repeatedly say they "disappear" on your head and can be worn for hours or all day, often rated more comfortable than the Sony XM6, Bose QC45, and even AirPods Max
Best-in-class active noise cancelling, especially for steady low-frequency noise like airplane engines, HVAC, and trains
Rich, detailed sound with punchy bass that many say sounds great right out of the box without needing EQ

Owners complain about

A persistent white-noise/hissing sound from the ANC circuit that owners describe as annoying during quiet moments, calls, and pauses in audio
A firmware update stripped out features many relied on, including cycling between paired Bluetooth devices via the headphone button, multipoint switching, and battery-percentage announcements on power-up
Creaking, popping, or clicking noises from the hinges and headband, plus a jarring "thump" when the adaptive ANC reacts to sudden noises like a door slamming

Full owner report →

Sennheiser HD 660S2

61%of 231 owners recommend

61% recommend · 20% neutral · 19% don't

Owners praise

Lush, natural mids and vocals with classic Sennheiser timbre
Deeper, richer bass with much better sub-bass extension than the older 6x0
Excellent imaging and soundstage for gaming and movies

Owners complain about

Dark, veiled or muffled-sounding presentation
Loses the forward midrange magic of the cheaper 600/650

Full owner report →

Which should you buy?

Get the Bose QuietComfort Ultra Headphones (2nd Gen) if

✓Frequent travelers who want top-tier ANC and all-day comfort on long flights
✓Glasses wearers and long-session listeners who prioritize a soft, low-clamp fit
✓Upgraders from Bose QC35/QC45 who value premium build over Sony's plastic feel
✓Listeners who want strong out-of-the-box sound without needing an EQ

Skip it if

People who make lots of calls, since mic and call quality draw frequent complaints
Anyone needing to fully disable ANC, since wind noise and hiss bother some owners

Get the Sennheiser HD 660S2 if

✓HD6x0 owners wanting more bass extension and treble sparkle
✓All-day listeners who want a warm, fatigue-free sound
✓Gaming, movie, and music all-rounder seekers
✓Metal, rock, and EDM fans wanting fuller low end

Skip it if

Those wanting a wide, expansive soundstage over intimate presentation
Purists chasing the classic 600/650 midrange, which feels recessed

What Bose QuietComfort Ultra Headphones (2nd Gen) owners say

“My ultra used daily for over a year is still working great. Had some firmware issue at the start but currently it is Ok. Good anc, great sound and sturdy.”
— GrumpyBitFlipper on Reddit

“I come from the xm5 earbuds and just bought the QC Ultra 2nd gen’s because even though I loved the Sony’s, I don’t like wearing them knowing there’s too much toxic chemicals in them.”
— therealpurpledolpin on Reddit

“but not the Ultras (not worth the price increase imo)”
— xolavenderwitch on Reddit

What Sennheiser HD 660S2 owners say

“I've had it for 5 years now and I still consider it the best of the 600 series”
— @o.f.ftrack3444 on YouTube

“They are my go-to primary headphones.”
— @scottlowell493 on YouTube

“At $250-$350 I would consider giving these a go at $600 they are a pass.”
— @mindhead1 on YouTube

Bose QuietComfort Ultra Headphones (2nd Gen) vs Sennheiser HD 660S2: frequently asked questions

Is the Bose QuietComfort Ultra Headphones (2nd Gen) or the Sennheiser HD 660S2 better?

Real owners lean toward the Sennheiser HD 660S2: 61% of 231 owners recommend it, vs 35% of 474 for the Bose QuietComfort Ultra Headphones (2nd Gen).

Who should get the Bose QuietComfort Ultra Headphones (2nd Gen)?

Owners point the Bose QuietComfort Ultra Headphones (2nd Gen) at frequent travelers who want top-tier ANC and all-day comfort on long flights, and glasses wearers and long-session listeners who prioritize a soft, low-clamp fit.

Who should get the Sennheiser HD 660S2?

Owners point the Sennheiser HD 660S2 at hD6x0 owners wanting more bass extension and treble sparkle, and all-day listeners who want a warm, fatigue-free sound.

What do owners complain about?

The most-cited downside of the Bose QuietComfort Ultra Headphones (2nd Gen) is a persistent white-noise/hissing sound from the ANC circuit that owners describe as annoying during quiet moments, calls, and pauses in audio. For the Sennheiser HD 660S2, it's dark, veiled or muffled-sounding presentation.