Scored on 231 verified owner verdicts, from 3,266 comments read across 6 communities
TL;DR
A near-universally loved open-back that wins praise for tight, punchy bass and detailed, fatigue-free sound; an HD600/650 upgrade that needs a decent amp to shine.
61% of 231 verified owners recommend the Sennheiser HD 660S2, based on real owner verdicts aggregated from Reddit, enthusiast forums, and YouTube.
3,266 comments reviewed · scored on the 231 clearest verdicts
61%
Recommend
142 owners
20%
Neutral
44 owners
19%
Don't recommend
45 owners
Last 6 months:62% recommend(16 recent verdicts)→ holding steady vs older reviews
Source
Breakdown
Score
N
Counted in the score
Reddit
63%
222
Other forumsAudio Science Review, Head-Fi
25%
8
Independent blogsiIndependent blogs with no affiliate links or paid relationship — we checked every one.no affiliate links
100%
2
Reviewed, but not counted — and why
YouTubeiOrdinary owner comments (not the reviewer), but here they sit too far from the owner consensus on Reddit and forums — channel comment sections can skew heavily positive or negative by trend — so they're shown for perspective and kept out of the score.owner comments
44%
200
No clear verdictiGood-to-know notes — setup, tips, and things to watch for. We use them for the pros, cons, and who it's for, but they don't reflect a definitive opinion on the product, so they're never counted in the score. See the 'Good to know' section below the quotes.Setup, tips & quirks
—
5
The headline score reflects owners (Reddit, enthusiast forums), independent lab tests, blogs with no affiliate links, and YouTube owner-comments when they line up with owners. YouTube is shown for perspective but kept out here — hover the i for why.
What owners like
Lush, natural mids and vocals with classic Sennheiser timbre · 40 · 17%
Deeper, richer bass with much better sub-bass extension than the older 6x0 · 38 · 16%
Excellent imaging and soundstage for gaming and movies · 33 · 14%
Favorite of the HD6x0 family and a clear all-round upgrade · 30 · 13%
Comfortable for hours of listening with little to no fatigue · 28 · 12%
What owners flag
Dark, veiled or muffled-sounding presentation · 26 · 11%
Loses the forward midrange magic of the cheaper 600/650 · 23 · 10%
Who it's for
A great fit 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
Look elsewhere if
Those wanting a wide, expansive soundstage over intimate presentation
Purists chasing the classic 600/650 midrange, which feels recessed
People sensitive to strong clamp force over long sessions
Synthesized from what Sennheiser HD 660S2 owners say — not a spec sheet.
Retailers' own star averages, for comparison — separate from our vetted owner-verdict score above.
Top quotes, sourced
3,266 reviewed · 352 shown
Sentiment
Community
Sort
YouTube— neutral
“I do enjoy switching to HD660s now and then for its different sound signature”
YouTube▼ don’t recommend
“At $250-$350 I would consider giving these a go at $600 they are a pass.”
YouTube▲ recommend
“I've had it for 5 years now and I still consider it the best of the 600 series”
YouTube— neutral
“The 660s win because they look cooler”
YouTube▼ don’t recommend
“I have to agree with the complaint on the box, at $600 you should be getting something way better than that.”
YouTube▲ recommend
“They are my go-to primary headphones.”
YouTube— neutral
“I'm happy that this is not better (for me)”
YouTube▲ recommend
“It's not just louder bass. It's more nimble, more detailed. Play a song with a fast, complex bass line, and you'll hear each note individually on the S2, while the 6XX blurs them with or without EQ.”
YouTube▼ don’t recommend
“I'm gonna have to go with the older, equally as good model lmao”
YouTube▲ recommend
“I absolutely love the HD660S2, definitely an upgrade to the HD600”
YouTube▼ don’t recommend
“I have hard time believing you that 660S2 are better than 660s yet still worse than 650”
YouTube— neutral
“This is cool but will probably stick with the 660S though, both due to liking things a little flatter”
YouTube▼ don’t recommend
“So its a less extended 6xx for almost double the price?”
YouTube— neutral
“I am happy about the sound profil and the quality. The retail price is kind of ridiculous though”
YouTube▲ recommend
“I am really enjoying them. I pre-o ordered and once the reviews started rolling in I was concerned that I made a mistake”
YouTube— neutral
“660s2 sounds like it’ll be too bright for me”
YouTube▲ recommend
“the S2 is my favorite of the 600 series. By a wide margin. I enjoy the added kick in the pants out of the bass performance as well as the extended upper frequencies.”
YouTube▼ don’t recommend
“not really better than the 660S (and because of the big price difference… I would pay 660S”
YouTube— neutral
“The new HD660 has great clarity but I prefer the original HD600 sound the most from all 600 Series.”
YouTube▲ recommend
“I liked the 650 better (with eq) and the 660s the best.”
YouTube▼ don’t recommend
“I've never had a Sennheiser with a slamy punchy bass. I guess this is no exception.”
YouTube▼ don’t recommend
“Hearing that the bass extension isn’t as good as the anemic 6xx is disappointing to say the least.”
YouTube▲ recommend
“Just received my 660S2'S today wow what a difference from the 6XX”
Reddit— neutral
“I have the 660s2 and the hd800s, the soundstage is definitely better and the comfort imo is way better but in saying that I don't think it's worth replacing unless soundstage and imagining is something you really want.”
Practical notes owners raise — setup, quirks, and issues to watch for. They don't say whether the person likes the product, so they're not counted in the score, but they inform the pros, cons, and who it's for.
Redditⓘ good to know
“I have HD660S2, and from my experience, they benefit from proper amplification, the voltage to be exact.”
Redditⓘ good to know
“The 660S2 is luscious, intimate, and engaging. Excellent for intimate acoustic music or jazz.”
Audio Science Reviewⓘ good to know
“Cable is not boomy or rather microphonic, very silent, relatively flexible and light as well. Especially compared to the thick chungus you get with the HD800S.”
Redditⓘ good to know
“My own HD660s2 didn't wear out in two years almost at all. Maybe plastic bended ever so slightly like 2%, but earpads wear was way noticeable.”
Audio Science Reviewⓘ good to know
“don't give it a quick listen in a store. It won't impress like some other headphones do. Give it some time and throw all kinds of music at it.”
