Sennheiser HD660S2 Headphone Review - Does S2 Stand for Strike 2?

The HD660S2 was a loan from a friend of the channel. Thanks!
Buy from Audio 46: audio46.com/products/sennheis...
Sennheiser HD660S2 Website: www.sennheiser-hearing.com/en...
My HD660S2 First Impressions: • Sennheiser HD660s2 Hea...
My HD660S1 written review: www.head-fi.org/showcase/senn...
My Other Sennheiser Reviews:
HD58X Jubilee: • MassDrop + Sennheiser ...
HD600: • Sennheiser HD600 (New ...
HD6XX: • Massdrop + Sennheiser ...
HD800 S: • Sennheiser HD800s & HD...
My Reviews of Other Mentioned Gear...
Beyerdynamic DT880: • Beyerdynamic DT880 600...
Cayin HA-1AMK2: • Cayin HA-1AMK2 Vacuum ...
Chord Hugo 2: • Chord Hugo 2 Transport...
Erzetich Perfidus: • Erzetich Perfidus "Evi...
HiFiMan Edition XS: • HiFiMan Edition XS Hea...
Musician Draco: • Musician Draco R2R DAC...
Schiit Modi Multibit 2: • Schiit Modi Multibit 2...
Schiit Nitsch Magni Piety: • Nitsch X Schiit Magni...
SMSL VMV D1se: • SMSL VMV D1se DAC Revi...
My Hearing Quirks: • WaveTheory Reviews Wav...
Timestamps...
00:00 Intro, Pricing, Disclaimers
01:04 Shameless Self Promotion
01:31 Does S2 Stand for Strike 2?
04:11 Build, Comfort, Specs
09:06 Test Gear
09:59 A Note on Break-In
10:56 Sound
18:46 Comparison with DT880
20:18 Comparison with Edition XS
25:01 So Does S2 Stand for Strike 2?

[@tomdavis6371]

S1 is a headphone I have not heard but I own S2, 600 and 6XX so I can say this much... the S2 is an excellent sounding headphone. It's got a nice kick in the bottom end, a terrific elevated top end that my 62 year old ears appreciate and that wonderful Sennheiser mid-range which I find to be a bit more expansive. I also don't hear that Sennheiser veil in the S2 and given that I was able to buy mine as an open-box pair from a very reputable dealer with full warranty and as brand new for $400, it's a terrific addition to my stable.

[@SpiritofPoison]

I bought them a few days ago for $290

[@BillGrady]

A very good, thorough, and fair review of the S2. All valid points, especially about the price vs. value. I’m really enjoying the S2 on my system with my music library so I’ll be keeping these. For me these were more of a solid hit than a foul ball, but I can also see why others may not see it that way. It’s the first “flavor” of the 600 series that I’ve connected with, and I previously owned a HD 580 for nearly 28 years. I’m sure the S2 will last that long as well. You also share my opinion on the build quality of Hifiman, especially looking 10 years down the road. And then there’s the loose fit on the Edition XS. Good for some, not for all. Nice job on the review! I’m done buying gear for a few years but will remain a subscriber because I value your opinion on what’s new within the hobby. Right now you’re the best out there, no question.

[@mtnmankeith9069]

Thanks for the review!

[@joseluishernandezseptien]

Great review! The baseball analogy is very smart and it works well in this context. I hope Sennheiser listens to you because market awareness is a healthy practice for improving products in any line, at the very least it should prevent a “foul ball”. Thank you!!!

[@SimonP2]

Nice review. Thanks for the comparison with the XS.

[@TimpTim]

Missed this earlier, but thanks. Love the baseball analogy...that part was a hit!

[@maciejgeming8555]

Thanks for very informative review. Your thoughts about 600 / 6XXs are closest to my own perspective. Do You have any plans of reviewing NDH 30?

[@Bushviking]

Great review. I use my Edition XS on a SS-amp for "critical listening" and music that needs the space. I use my HD600 on a Darkvoice if I like my listening intimate, smooth and fun. I have listened to others but these 2 combos "scratch my itch", and sounds like I can safely give the S2 a miss too.

[@larrym5606]

A nice thorough review as always very technical without getting into the measurement's nonsense. I do feel you, as some of the other reviewers are very hesitant to give the S2 credit for what it does well. I understand why everyone is hung up on the price, but nothing is a value since covid. :) I would like to see a review of the product without the price holding it back. These are now available in the $450-500 price point, HD650 are around $350-400, and HD600 between $300 - 400 depending on the day and website (amazon). This falls right in line with the pricing structure Sennheiser has had for years... The S2 is a step forward in my opinion, adding the strengths of the 600 and 650 in one package, too me it is an amazing headphone that reviewers just keep reviewing the price and not the product. EVERY hifiman product is OVERPRICED, in reality. Based on build quality, and quality control, that is a bigger issue to me, Sennheiser offers a quality product that will last for generations, and imho they don't need to recreate the wheel, when they have a near perfect product line in the 600 series, some minor tweaks and revisions along the way is all that is needed, and that is exactly what they have done. I am glad I took the plunge and tried them. Your review wasn't negative, but hesitant to point out, or should I say give credit on the positive aspects of this headphone and where it shines, you mentioned some good things it does well, but with a bunch of hesitation and/or reluctancy. I purchased this brand new for $450, how would you review them at that price point? I am just wondering what some consider a fair price on this headphone. I appreciate your opinion, and really enjoy your work. I hope this comment doesn't come across the wrong way. I know you asked for a simply was this a negative or positive review. I don't believe it was either. I do feel this was a very good review based on your opinion surrounding value. I appreciate you are conscious of that and understand that we are all not wealthy, and able to spend endless money!! Do you feel these should be prices the same as the HD600, or HD650's? The 650 cost more than the 600, what do you deem a fair price for the 660s2? Keep up the great work.

[@ricardocarmo3464]

I was trying to get the HD660S but now i'm torned, first because the HD660S are unavailable and second because i think that spending a bit more will make me keep them for a long time. Specially since i'm coming from the 2014 Sennheiser 373D. So i was going for a HD660S2 + FioO K7 what do you think ?

[@larrym5606]

@@ricardocarmo3464 I think overall you will be very pleased with the performance of these headphones. I am not very familiar with the FiiO k7. I use this with the Zen Can and Zen Dac, along with a tube pre amp when at my desk. I use a FiiO BTR7 when chilling on the couch or on the go. The hd660s2 sounds amazing with all, they even sound good with a simply dongle Dac I purchased for $20 on Amazon. Overall I stand by my initial thoughts and comments on this headphone. They are simply awesome to ME… others and your mileage may vary. But I honestly feel you will love them, especially if you like the overall Sennheiser sound signature these are a mature sounding HD600/650. Good luck and let me know which way you went.

[@SpiritofPoison]

@@ricardocarmo3464I just bought the S2 for $295 lol. You can find them for abt ~$360 usually though. I recommend it.

[@KenValent]

I have the oppo pm-2 magna planer headphones. Can you recommend current magnaplaner headphones to upgrade to?

[@richard5123]

First time here like+subbed cheers

[@EricRosenfield]

Constructive criticism: I think you'd do well not to bury the lede in your reviews, which I think you do pretty consistently. For example, in the "sound" section what I want to know is whether or not you think it's better or worse than the HD600 or HD6XX or who this might be for; saying it has a "more bass" in isolation doesn't tell me anything (especially if you don't tell me whether it makes the headphones sound better or worse or in a way you like or dislike). Then you can go from there and talk about the particulars. You could even be up front at the top of your review and tell us if you think it's better or worse. Contrary to what you might suppose, that actually makes the video more engaging because now I want to know _why_ you think that's the case. Otherwise the video feels like it meanders and doesn't get to the point fast enough, which, particularly with a 30 minute video makes me more likely to click away to something else. Hope this helps!

[@wavetheorysound]

Thanks, Eric. I argue with myself on the better approach here. The feedback is appreciated.

[@carminedesanto6746]

I’ll keep rocking my Sen’s 650’s 🙂

[@bryansheridan6434]

While I do not have the ears or chops that most of you have.. been into this hobby for 3 years. These are my favorite headphones. I am wear them almost all day after breaking them in. Had the 650 for six months. I prefer these hands down. So give them a listen and decide. For comparison my other go to HP LCD-X 2022. Mostly listen on M11 Pro ESS. Asgard II and Woo Firefly 3rd gen.

[@greccoox]

btw perfect analogy with baseball, and perfect thought about the lack of marketing thing, PERFECT.

[@jimhaskayne5860]

I got a pair of these on Amazon for $300 CDN off which made the $500 CdN. What a bargain as I love them. I’m no audiophile but I have been into electronics since I was 11 and sold high end stereo equipment since 1982. I have never heard a better pair of cans

[@GG-zv9ku]

I enjoy mine. Seenheiser tent to put them on sale over time so no worries about price after a while

[@mariodrv]

Good review.

[@stealpriest2245]

Tried it in a headphone bar two weeks ago. Unlike 600, it sounds more like recording than real and natural sound. However, it provide better spatial effect and the deeper pad feels more comfortable. Also the subbase enhancement is definitely noticeable to me. A good headphone for sure but I think it is a bit overpriced. Honestly, I enjoy 600 more than this new released version.

[@wewlad107]

You should be replacing your 6x0 pads anyways...

[@uwemariansteinke972]

(Hd660s 2 or hifiman ananda?...thanks

[@yankee7809]

Around 23 years ago I purchased a Sennheiser HD600. I still have it after many amps, sources and other pieces of Hi Fi gear have come and gone. I've listened to many different phones during this time but never found one even at multiples of the amount of money that I liked so well that I was willing to replace them with. They can be beaten but not for the amount of money I 'm willing to spend. I do own a pair of 6XX's so if something happens to the old guy I will have a phone to listen to while repairs are made. I believe to beat them and still call it a 6 series phone Sennheiser would have to fundamentally redesign the drivers and start over with the basic physical outward appearance the only holdover.

[@chungang7037]

I think the only real upgrade for the HD600 is the Focal Clear or T1 by Beyerdynamic [2nd gen]. The latter is a pain to run because you need an amp that can handle 600ohm and the Clears hard to find and have been discontinued, and even then I wasn't convinced they were worth the money after hearing both.

[@pursuit9827]

Like your honest opinion! I will just keep my 660S. I have listened many comparisons online between S and S2, and the difference is really small. S2 may have lifted the veil, but it is still clearly there.

[@SpiritofPoison]

I’ve heard many say the difference is not small as well.

[@Tripokaridos22]

660s are amazing and in my opinion the biggest soundstage of them all , also the most lively of them all. S2 are warmer compared to 660s, 660s are thinner sounding vs S2. In my opinion all HD6 line is amazing thats why i keep all of them. BUT S1 and S2 are technically better in my opinion. Between S2 and S1 ... S2 are warmer more sub bass and more smooth relaxing headphones. If i had to choose one of them all will be S2 . Does it worth buying if u already have 660s ? I was in the same position and i thought that will sound the same ... they dont . 660s by the way are not 6XX they don have any veil or muddiness .

[@Tripokaridos22]

@@SpiritofPoison There is a difference , both are great ... but S2 do have better low end by keeping the speed, imaging, separation of 660s all that in a smoother way than 660s. Honestly 660s are the most Lively sound headphone of ALL HD6 line . S2 are warmer than 660s, but not warmer than 650. I would say the warmest is 650>660s2>600>660s . strange but true.

[@scottlowell493]

It's as if Tyll has passed the torch. We needed another Tyll. That is, someone to thoughtfully, articulately and honestly review headphones sans the fan boi hype. Pragmatic and to the point. Anything less is worthless. Well done on all the reviews that I have seen so far! Senn just seems to slightly nudge response from the 5XX-7XX. It's a bit more profound than Grado changes in the price bracket.

[@TheKizersoze13]

I like my 660s but I did buy them for $320. I’ll be getting these when the price drops a little.

[@mala2743]

If anyone is able & willing to share thoughts on where the 560S fits into the mix, I’d appreciate that. Cheers.

[@KingFiercer_zip]

I'm pretty sure the HD560S is somewhere between the HD600 and HD660S2, they sound more airy and open than the HD660S and HD650, but don't have the density and timbers of the more expensive models. Good model for gaming, also easy to amplify due to 150 ohms.

[@mala2743]

@@KingFiercer_zip I appreciate the feedback. I’m relatively new to the hobby. The 560S was the first “audiophile” headphone I owned. I really enjoyed it for many genres of music. I actually made the move of upgrading to the 660S (version 1)-and unfortunately just cannot sync with the 660S even after many hours trying. I never heard the 600, 650, or 6xx.

[@KingFiercer_zip]

​@@mala2743 In my opinion HD660S is the good for heavy and high-paced, raw-sounding, modern and bright music, they're good for long listening without any fatigue. Because they have a slight dip in the upper mids and highs, they are slightly less airy and less expressive with female vocals, but very versatile and comfortable with almost any genres of music. Also, like the HD700 and HD560S, they have slightly better imaging and soundstage compared to older HD600/HD650, so they are also better for gaming. You most likely like a more open sound. With a brighter gear (amp, DAC) and brighter music, the HD660S could be more comfortable and enjoyable. HD600 and HD660S2 might suit you better, if you didn't like HD660S1 because of their darker nature.

[@mala2743]

@@KingFiercer_zip Thanks again. I appreciate your helpful feedback and insight. Cheers.

[@yamato1420]

The $500 price range is finally being filled out with appropriate contenders that also clearly transcend the $100-$250 price range. Sennheiser probably thought that they'd jump into it as early as they could with a rebrand of a headphone that is essentially ~$200 now. Hifiman and Focal did it much better: they took their tried and tested $1000+ sets, stripped them down without taking essential characteristics like sub-bass and staging away, and moved those into the lower price ranges. Sennheiser really should try to do something new one of these days.

[@mikeg2491]

I have a Focal Utopia and a Radiance. Honestly the Radiance is 90% of the quality of the Utopia but at 25% of the cost, and frankly it’s more pleasant to listen to with it’s warmer signature, bass shelf and best of all, no clipping problems like the high-end open backs.

[@SpiritofPoison]

I wouldn’t call this a rebrand

[@Tripokaridos22]

I have to Disagree , I own and use all HD6 line and 58x... HD 660s and S2 have way better imaging, speed, separation and sense of soundstage , honestly its not even comparable . BUT HD600 have the best vocals they create a bubble around them and HD650 have the smoothest warmer sound of them all. I really dont get it how anyone can say that on a technical level 600,650,580x, are close to 660s and S2... I can understand if someone told me i like more HD600 or HD650 for sound signature ... But on a technical level ? Nope no way .

[@saint_odonnell]

You are absolutely bang on the money! Haven’t heard anyone say it better yet. I think everyone wants Sennheiser to win but they keep on slinging us foul balls, resting on their laurels and past victories. It’s time they stood up to the plate and truly swing for the grand stands like their mighty reputation affords them from days of yore.

[@sebanambrus9265]

Can you compare it to the focal clear?

[@mariodrv]

LOL

[@sebanambrus9265]

@@mariodrv dog

[@hitechrr]

My senn HD580 is over 30 years old and the only thing changed it the foam.

[@FabioKasper]

I'll get mine for 350 or less. Brand new. Not in a rush here.

[@SpiritofPoison]

I just bought these for $295 without tax.

[@h-dawg6462]

S2 is an outline of heart ♥ (sort of!!)

[@ronrusso6133]

Was never thrilled with my 660s, but I kept them for late night movie enjoyment. They clip at my preferred volume/bass levels with music, so Edition XS to the rescue. I'll pass on 660S2.

[@SpiritofPoison]

You should definitely hear it yourself before passing.

[@colingordon0986]

I mean there not a bad headphone if you don’t have any of the 600 series headphones! Just not worth upgrading if you already have the 600, 650 or original 660

[@alainmc4147]

Get the HD 560s for review 🙏

[@shreddherring]

An updated hd700 series release would make a lot more sense than rehashing the hd600 sound over and over. If you want a reason to upgrade from the 600 series, but cant afford an 800, the 660 isnt that compelling as its made to sound like the 600... You aren't getting enough difference to justify the purchase. And as the driver was initially made for the 700 series, you're probably missing out on some of the potential by putting it in a 600 frame and tuning it to be a 600 clone

[@provisionalhypothesis]

I mean the 660 was using the HD700 driver anyway. Don't expect Senn to lead at this point

[@arthurhaywood2184]

I concur. My opinion on the 660S2 was there was nothing to differentiate it from the already existing 600 models. More of the same…. I’d much prefer that Sennheiser bring back an improved 700 Series in both an open and closed version while simultaneously filling up a gaping hole in their price range.

[@o.f.ftrack3444]

I think people are a little too selective when it comes to pricing. Most headphones in the mid to high price range are more expensive than they probably should be. I've listened to both the LCD-X and 660s side by side and of course the LCD-X is noticeably better. But......is it that much better to be worth 3 times the price? I would say yes if the 660s was $300. I've listened to the Utopia and it's absolutely amazing, but $4,500? I understand that every percent in improvements might result in a bump in price but no one seems to look at it from that point of view when it comes to the 600 series. I think the problem that any new 600 series headphone will have is that it has to compete with the nostalgia that comes with the 600 and 650.

[@thaflybear]

If price wasn't a factor, would you pick 660s2 over 650/600?

[@provisionalhypothesis]

no it's not if you have to ask about price. if price is no object you don't care what you pay

[@nikolaygramchev]

Waaaau, the DT880 rocks it better! and the XS is beating it badly. So, no place for the S2 in the line of DT880, DT1990, Elegia, HD700, Arya, HD800s

[@greccoox]

strike 2 means in our wallets, with terrible adapter. With this price point no matter what, should come with amazing cable. but is ok is easier to do a copy and paste of some product that impact and take the extra $ for profit.

[@SeanLiu4]

As someone who bought the HD660 (original/S1) at $500 USD , I can confirm that's the 660s series is overpriced. Its a pleasing and easy headphone to listen to, but even at 150 ohms, its not efficient enough to drive from a mobile phone, not satisfying enough when driving from your computer's on-board audio. The lack of improvements or any further stand-out qualities from its predecessors/siblings never ever warranted the $500 USD price tag. Now tack on an additional $100 USD for minor adjustments and some sub-bass extension??? That...doesn't sound worth the price..... I'd rather buy the Hifiman Ananda at $700 or even an Audeze LCD-2F/2C ($800 for 2C, around $900 for 2F)

[@supergwizzo]

660s2 is 300 ohm .. 😊

[@Michael_mki233]

Not really sure an argument can be made for this being a positive review, lol. Price-wise though, keep in mind that this is the same company that charges $2000 for the HD820. It's a wonder they didn't charge $700-$750 for the 660S2. 🤣

[@wavetheorysound]

The more I think about it the more it bugs me TBH. I can understand overpricing the first edition. Everyone misses one here and there. But to release a 2nd version with the same core issue is... I'm not sure what it is exactly lol but it doesn't come across well.

[@Riotdrone]

bought a 660s2 for 400 bucks and i'm glad i'm not a real audiophile so i don't have to endlessly analyze and second guess myself. i just enjoy the headphones

[@chungang7037]

Well I am glad they screwed up. They need to find the engineers that were in charge of the HD600 and bring them out of retirement or find their dev notes and find out what worked and why. Only then can they know how to make something better, or scale up the performance to make the price tag worth it. You'd think they would have the resources to do so. That, or perhaps the HD600 was a fluke and they don't know why it performs as it does. Judging from the amount of ho-hum headphones they have made, with a litany of issues, I suspect it was a fluke. Come on Sennheiser, get the research and development going and science the shit out of it.

[@supergwizzo]

No factory seal on box feel cheap dark stuff in recordings not heard .. Sending these back..😮 total rip off 😊

[@carminedesanto6746]

At that price point, you better off saving a little more and getting the Meze’s 109 pro

[@I_beat_up_cuckolds]

Edition xs runs circles around meze 109 pro for 300 dollar less. Meze produce overpriced headphones but somehow escape criticism because ' oh look wood'.

[@pappsa8]

Still the hd600 the best in that line!

[@SpiritofPoison]

many people say this and many people say the opposite

[@shawnpwatsons1]

Try the Theiaudio Ghost against the 660S2 for $129 and report back.

[@yttean98]

Takes you 30min to review a pair of headphones, too long.

[@eiskalterorangensaft]

sennheiser hd660s2 is just a joke and a cashgrab compared to the price and market nowadys what we have. edition xs is WAY WAY BETTER and people who say the sennis are better than hifiman are just delusional. I want to buy a edition xs but am scared of the QC

[@beaverish]

The only headphones worth buying from the HD 6 series is the HD600. I have tried 650 and 660s and they both sounded like cheap 20$ headphones but with fancy exteriors.

[@KingFiercer_zip]

"20$ headphones" 🤣

[@beaverish]

@@KingFiercer_zip yessir.

[@kentbergstrom3020]

It's ridiculously overpriced, I bought an HD600 instead and couldn't be happier.

[@SpiritofPoison]

I got it for $295

[@I_beat_up_cuckolds]

Another example of a highly overpriced mediocre headphone is meze 109 pro The "how are they this cheap???" are the edition xs. Phenomenal cans

[@user-hb9fp4vs2f]

Too dam long homee.. Cut the BS analogies out and the video will be a great

[@JustAnotherRetard]

Average rodent brain tiktok scroller.