Customer Reviews

Excellent sound.

Can't imagine needing to spend any more (than what I paid for these) to get audiophile quality sound.

Have questions for
?

Crutchfield response on

Solid, True Phones for Reasonable Cost.

Light and easy to wear for long periods of time. The 660S2 is an excellent example of the sound difference you get with an open design vs. closed. I've tried a modest number of higher quality 'phones' and these are my current favorite by quite a margin. They seem to my ear to be very true and open sounding - no pun here. I haven't actually seen the response curve but it sounds admirably flat and stays that way across various sound levels. Build quality seems to be very good but time will tell.

Have questions for
?

Crutchfield response on

Worth the price.

Definitely better sound than my old HD 650. Much clearer and the sound has more detail. The total treble and bass is balanced.

Have questions for
?

Crutchfield response on

Great Sounding headphones

This is my first pair of open back headphones and I am loving them. The sound stage is great and very clear. I really like the crispness of the headphones and how they sound with every genre of music. I don't feel the bass is amazing, but it certainly is more than adequate. They are tight on the head out of the box, but they have been becoming more comfortable the more I use them. The ear cups are the perfect size for me and are very very comfortable. Overall, I would certainly recommend these headphones. Just make sure you have a decent headphone amp and you will be just fine.

Have questions for
?

Crutchfield response on

Great Sounding Headphones

I really wanted a good pair of headphones so I can listen to without disturbing anybody in the house. I've heard good things about Sennheiser headphones so I decided to give these a try. Man am I glad I did. They sound so good. Everything sounds perfect even at high volume. Best pair of headphones I've ever owned.

Have questions for
?

Crutchfield response on

Fine Sound for Classical Music

The first test out of the box was the opening minutes of Also sprach Zarathustra (Karajan/BerlinPO 1973 analog) - Wow!

Have questions for
?

Crutchfield response on

Amazing Sound!

I got a pair of these all the way back in December of 2022 and man, let me tell you, these have been the best headphones I have ever used in my life when it comes to natural sound staging. Additionally, I thought I wasn't going to be able to get as much bass response compared to some of Sennheiser's closed back headphones, but these set themselves great in comparison to any pair of headphones I've heard! GREAT PRODUCT!

Have questions for
?

Crutchfield response on

Solid addition to the HD600-series!

Big fan of these headphones - they've got enough of the HD600-series DNA to feel like a "fit" in the series but have a bit of their own thing going on so as to not make them a redundant addition. Great midrange and a non-fatiguing voicing like the other models in the series, though perhaps not quite as lush in the mids as the HD650. This is voiced a little more closely to the HD600 (a fairly neutral but slightly warm tilt) but what it adds is a little more upper end air and bass is stronger. Maybe not a true bass-head set of cans, but if you're looking for that Sennheiser HD600-series sound and comfort but want a little better bass and a tad more neutrality in the mids than the HD650, this would be an excellent choice!

Have questions for
?

Crutchfield response on

No base but trouble .

No base, no power or fidelity. I'm blown away how poor these sound coupled with a very tight fit . The sound of the open back penetrates throughout the house not giving everyone privacy from what you're listening. Overall a decent design (worth the 1 star) but maybe just maybe these sound better with an headphones amp.? Who knows, not willing to take that chance, I couldn't return these fast enough, not worth the time.

Have questions for
?

Crutchfield response on 12/17/2024

Sorin contacted our Customer Support team and set up a return. Purchases from Crutchfield can be returned or exchanged within 60 days.

Sennheiser HD 660S2

After having purchased wireless headphones and earbuds for the past ten years, I decided to invest in a pair of wired headphones. There IS a positive difference, but as someone who would not classify oneself as an audiophile, I can only say that these Sennheiser's create a noticeably more expansive experience. The sound moves my spirit. I also hear little licks and short contributions from instruments that I have heretofore not noticed in my past experiences with the same songs. When used with a Dragonfly Cobalt attached to an iPhone, the sound is impactful, and slightly more so than with the AirPods Pro, second generation, which I shall always cherish for getting around town and traveling. The setup is unwieldy to carry around for long distances, but I bought these headphones for home use so as to not negatively impact other family members. It's well worth the workaround around I use to do home chores and walkabouts. You won't be sorry ...

Have questions for
?

Crutchfield response on

Best Headphones

I have perused several headphones for my PC over the years including those that weren't just gaming headphones. These are by far the best I have ever had.

Have questions for
?

Crutchfield response on

Reommended

I have really enjoyed these headphones in the short time that I've owned them. I've got them plugged into a Cambridge DAC-MAGIC 200M at my office. The open design of these headphones provide a really open and large sound . The Cambridge unit is powering them to a satisfying level. They are also very comfortable and stable.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

nice sound

Have questions for
?

Crutchfield response on

Good quality, but comfort is a problem . . .

Bought these after wearing out a pair of Sony open-backs that I've had for 29 years. I don't demand a lot out of headphones other than Are they musical? Are they comfortable? and Are they reasonably-priced? I think these deliver good sound. I use a Bellari PA550 and their EQ570 unit. The PA550 has a nice headphone pre-amp. I listen to cassettes, CDs, & vinyl and it all sounds musical. Bass midrange & treble are all present and balanced. Testing them with mixes that do a lot of panning (ELP, Floyd, Queen, etc.) reveals that these cans track as they should. Also, I listen to TV streaming audio through my Denon DRA-900H, and the quality is just fine. Comfort is a different issue, because these are *way* too snug; I know no one likes loose cans, but why design them to mimic your temples being stuck in a vise? Another complaint is loosening them for a more comfortable fit and then when you remove them, it's too easy to get your hair pinched in the side adjustments. I nearly returned them because of these issues, but I wanted to see if the breaking-in period helped them settle down. After five months, let's just say the jury is still out.... And then the cost kind of shook me. A $100 pair of Sony cans purchased in 1995 compared to $700 Sennheisers in 2024. That's way more than keeping with inflation, in my view. I could've gone cheaper, but didn't dare. If comfort is extremely important, look elsewhere. If you can overlook it, these may

Have questions for
?

Crutchfield response on

Excellent build quality, perfect audio?

I normally don't review products but these headphones demand it. They are by far the best I have ever listened to and leave me wondering just how much better it can get.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

Great sound, comfortable to wear, going to order another pair

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

The 660S2 is a really solid set of cans! Very true to the Sennheiser sound but with an extra dose of low end to round out the really well presented mids and highs. Even though they're a high impedance, I didn't struggle to power them off of any of my gear. When hooked up to something like the Cambridge Audio DacMagic 200M though, they really shine! Comfort wise, the clamping force is pretty snug out of the box, but they do loosen up slightly to give you a very secure fit without feeling like they are squeezing you.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

These are perfect! I was afraid the open back would be loud but it's not. Sounds are perfectly balanced, very natural. Fit is very comfortable. Well-made headphones!

Have questions for
?

Crutchfield response on

Prefer to the 6XX

I've had a pair of Massdrop HD6XX for years, and so decided to give these a shot given their favorable reviews and sale price (bonus on the open box from Crutchfield). I wasn't sure how different they would be from the 6XX, but was pleasantly surprised. They're not night and day - the two headphones are in the same line after all - but the differences and slight upgrade over the 6XX made me keep the 660S2. The biggest improvement is the bass and soundstage. When swapping them back and forth, the 6XX feels far more congested than the S2. The bass on the S2 isn't crazy as compared to the 6XX, but it definitely has more detail and doesn't bleed into the mids like on the 6XX. Lastly, I also noticed that the S2 have a touch more detail and sparkle in the treble, which I like. The only negative I could find was that the lovely mids from the 6XX took a bit of a hit on the S2. Vocals still sound much better on the 6XX, so I will be keeping those for when listening to singer/songwriter type music. Are they worth the upgrade at full retail? I honestly don't think so - I would just have kept the 6XX. But at the sale price (I paid $360 open box) they definitely are.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

Used to have the original 660S. They were the most comfortable headphone I have ever owned. That was many years ago. I don't know what happened to this model and why Sennheiser went from super comfortable to very uncomfortable in only one iteration. The clamping force is very high and the top of my head hurts after 5 minutes because the foam is so rigid. I hope these will break in. Keeping them for now as the sound is top notch for metal, which I listen to almost exclusively.

Have questions for
?

Crutchfield response on

Sonically neutral

These are incredible headphones in that they provide a high quality listening experience. I have listened so far to CDs as intimate as Nanci Griffith live at Anderson Fair; as dynamic as the Verdi Requiem; as harmonically dense as the Durufle Requiem with only organ accompaniment; and as damaged as a 50 year old LP of the Kingston Trio on my Planar 3 turntable. These headphones are absolutely as neutral as science and technology can deliver. I heard what was on the source material with all its flaws. If the recording is limited, that's what you hear. If it is exemplary, you'll hear that. The soundstage is expansive. The comfort is wonderful. I'm delighted with the purchase.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

I was looking for headphones to listen to while at my desk, but better sound than most Bluetooth headphones can provide. These deliver. Amazing sound!

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

I have always owned a pair of Sennheiser headphones, going back to at least since the mid 70s, and the 660S2 model is probably the most comfortable pair I've ever owned. The sound is great and the bass is very well defined, especially with an open air design like the 660S2. Midrange and upper range is also very clear and distinct. I also still have an old pair of 565 Ovations that sound great too, but the 660S2s are a definite improvement over the older ones. Sennheiser makes great headphones.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

Great looking, great fit & most important superb sound. Merry xmas to me!

Have questions for
?

Crutchfield response on

Not a Surprise

Not a surprise because I've been researching various headphones for about one year. These 660S2s are comfortable and delivery my music cleanly, authentically & offer the low end like no other headphones I've sampled. Very satisfied until the bug bites again.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

I am searching for a replacement for my old Sennheiser HD 650 (with Cardas cable) head phones. I listened to the HD 660S2 headphones for 2 days and will be returning them. To their credit, they are superior to the HD 650 in the bass and treble presentations of recordings; however, I found the solo instrument, whether it be the vocals or an instrument, have been moved from the foreground of the sound stage to the background which is disappointing for me. Also, the included cable is much shorter than my 10 foot Cardas cable as well as lacking in the sonic qualities of the Cardas cable. I'm very thankful to the Crutchfield audio advisors for their assistance and very appreciative of the 60 day return policy, too!

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

I've had my Sennheiser HD 280 headphones for over 25 years and they still sound great... but not as great as these 660S2s! I tested them with the Bluesound NODE X, which has a really nice built-in headphone amp. They delivered great, well-balanced detail on Steely Dan's Gaucho and Stevie Wonder's Hotter Than July albums. I appreciated the cushy-but-firm fit and could easily listen through these 'phones for hours at a time. I also appreciated the packaging, storage bag, and high-quality cables. Sennheiser is a model company in my eyes, doing what they do extremely well.

Have questions for
?

Crutchfield response on

What The Original 660s Should Have Been

This review is based on a short period of time with the S2's. Preface by saying that I've been using HD650's for years. I tried the original HD660s and simply couldn't find an improvement on the 650's. Yes they were different, but not better. At this time I have to S2 is better than the HD650's at many things. As good as the 650's at most everything. The S2 is what the original 660s should have been. It's amazing how a manufacturer can change so little hardware and drastically change the overall product. They're keepers!

Have questions for
?

Crutchfield response on

The best of the 600 series

Mine are an "open box" purchase. The headphone is like brand new albeit the Sennheiser box was a little worn. I'm a BIG Sennheiser fan and own or have owned many variations of their headphones or IEMs. The amount of clean bass that these generate is amazing and I can't detect any bleed over into the mid range. I find the treble is a little better and cleaner than my other 600 series headphones. At 300 ohms, these require an amp or dac/amp to sound their best. I use a iFi hip dac v2 to drive these. Plenty of power in that awesome dac/amp to power them. The only negative caveat is: The plastic housing at the end of the 3.5 mm plug is squared off at the end and stops the plug itself from going any deeper. It should be tapered and a hair longer. Mine barely makes a connection into the dac/amp itself and I've found that if you move much, the plug may loosen and fall out but YMMV. Enjoy the sound!

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

Great set of headphones. I have always used Sennheiser headphones and decided to upgrade. Great sound and are comfortable. Great quality at a decent price. If you don't want to spend $1000 for a set of headphones, I would recommend the Sennheiser 660S2.

Have questions for
?

Crutchfield response on

Sennheiser HD 660S2

Know Sennheiser audiophile sound with basic equipment

Have questions for
?

Crutchfield response on

Lovely open-back sound for bass lovers

These are my first serious pair of Sennheiser's though I have 2 other nice pairs of open-back phones, the HiFiMan Edition XS planar magnetics and the Beyerdynamic DT 1990 Pro. I usually prefer closed-backs, of which I have 3 pairs, because they tend to have better low bass extension and of course sound isolation. Compared to those, the HD660S2's compete very well in the bass delivery arena. I have not yet tested these with my mobile DAC/amp but they work very well my desktop amps: xDuoo MT-604 (with 4 GE JAN 5654W tubes) as well as the Schiit Jotunheim 2. Desktop DAC is SMSL VMV D1se connected via I2S HDMI to a Denafrips Iris which connects to a PC via USB for Qobuz. The HD660S2's sound quality is impressive over the musical range with nothing lacking. Bass, mids, and highs! However, the build quality is sub-par, especially for the price. Aesthetically, they haven't updated much from the HD660's. It's mostly plastic and has a cheap feel. The box it comes in is very small, nothing fancy. The carrying bag is a better-than-nothing situation but a carrying case should be expected at this price point. However, it is nice they have included both an unbalanced 6.35mm cable as well as a 4.4mm balanced cable, although the cable quality appears to be very basic. Unlike the Edition XS, these are well-suited to people with smaller heads. I had to extend the headband quite a bit to get it on comfortably. Having said that, they are comfortable once fitted, especially the ear

Have questions for
?

Crutchfield response on