Sennheiser HD 660S - Official Discussion

I think there is a difference, at least in my mind. Layering is the perception of multiple instruments playing the same note, violin, cello, tuba… what have you. Adds meat to the music. Instrument separation, as I will currently use it, is more about location (perhaps a simplification). So you could have a headphone that allows you to follow separate instruments fairly well but may not layer well when those instruments are called upon to play the same note - kind of smudged together. At least that is my current thinking, may change in 5 minutes.

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Focal Elear/Elex are song exploders. Due to their massive (exaggerated) dynamics they tend to pull instruments out. Given their clarity they don’t smudge so much a merge and magnify.


So would you term that as having exaggerated layering? Is that an enjoyable effect? Havent had the opportunity to hear any Focal stuff much less the Clear/Elex.

I’ve always loved the Elex for the way it makes its upper mid range fly at your ears. And you’re right, it is quite dynamic.

Separation or distancing of instruments rather than layering. It’s not so enjoyable unless you really like punchy, slamming dynamics. I don’t like them for regular use in many genres.

ELEAR, not Clear. The Clear is fantastically detailed and neutral. The Elear is a lower cost product. With a moderate retune it became the Mass(Drop) Elex. The Elex has less overwhelming bass, but still explodes songs.

Yes, it has a ton of glare. I spent a lot of time trying to reduce that…and now just use the Clear instead…


Maybe the glare was fixed with the Modius and Lyr 3? I’m not noticing them being nearly as sharp as they used to be. Might get the Clear in the future. How you like it compared to the Elex?

Never rely on gear to fix the shortcomings of headphones. Just my opinion.


We’ve trod this difference in the Focal threads – lots of great info from @Torq and others there.

The Clear is “clear” as in neutral, transparent, and extremely sensitive. One can hear lots of details and air. The Elex is punchy, intense, has high-mid glare. I’d honestly think twice about buying the Elex over anything in the Sennheiser 600 family, while the Clear is a thorough upgrade.

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Is this a Focal thread? Cough cough… :smile:

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My Review of the HD 660S now live on The Headphone Show’s YouTube channel!

Check it out here:


Just watched it. Great job!

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Good stuff Chrono,

It’s Thursday DSP night, and here I am testing your settings. Does the Track 6 in picture above look like your suggested EQ?

There are 3 other V-shape flavors and a flat representation available as well. Still trying to define yours. :smile:

Only conclusion though is: it’s genre and mix dependent. Nothing new after all. :+1:

Cheers. :beers:

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“Thursday DSP Night,” I like that haha

Yeah it looks pretty much exactly like my settings, although I ended up removing the fourth filter. I really appreciate you trying it out, hope you found it good in some tracks!



I am looking forward to trying these out. I bought an “open box” pair last week.

I am not a huge Sennheiser fan and have a checkered past with them. My current record is 2 and 2. I have bought three new amps this year and so figured I would give Sennheiser one more chance. I do like having a variety of sounds, so this will be interesting.

I will try to take several months to form a complete opinion on them.

I went to to get a 4.4mm to 4-pin XLR adapter, but no luck. I ended up rebuying a cheapie balanced cable that I bought last year instead.

Headphones are scheduled to land on Tuesday and I am looking forward to it!

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One of my favorites, great choice!

What’s good to know is that these respond really well to equalization. Of course I’d encourage you to first get familiar with them as they are, but if you’re just not quite feeling satisfied with them after a while, some tricks with EQ can work wonders.

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I will keep that in mind. I don’t listen to my music out of a computer, but I do have a Schiit Loki. It is pretty much just dedicated to my Koss Electrostatics system.
Honestly, if the headphones need to be EQ’d to work, I will probably just move them on. I make an exception for the Electrostats, because they sound like nothing else. However, without the Loki, the Electrostats would be gone in a week. :smiley:

I have three amps, one is tube, one is hybrid and one is SS. If they can’t find a home with one of those amps, then they will likely find a new home elsewhere.

After 2 months

Damn it Sennheiser. Two months with these cans and I have been reaching the 660S more often than the 6XX (still the daily driver).

First time I wore them I remember the sound being like a boosted ‘Presence’ knob in a guitar amp. Nowadays, after brain burn-in (or simply normalization as some say), it sounds so much natural to me. And the layering. It’s really cool even when in laid-back listening mode.


Mid focused songs. Being a guitar player hobbyist myself and someone who grew up in the 90s Rock/Grunge scene, crunched guitars are a must. And voice focused songs are part of this package as well.

I can’t speak for the bass/treble heads out there. YMMV. :grimacing:

Gear used: entry level DAC/Amp. E.g.: Modi 3 and Liquid Spark.

With :eyes: wide open

Every now and then there’s a sale on these cans, like when this post is being written, for instance. Benjamin Franklin x 4.

All arounder beast

Looking back Tyll’s review and many other DT1990 comparisons and stuff… So many negative reviews (or frustration) – relative-wise. This is the perfect example when hype trains benefit consumers looking for alternatives.

@Chrono, looking back this week’s video – on Tier 1 @Resolve’s classification – for 50 bucks more and conditioned to a sales campaign, it is a very competitive headphone. Assuming one follows the context up above, of course.

My 2 cents.

Cheers, :beers:


When I started my headphile (headphone audiophile) path many years ago the available choice in Italy was simple and straight: Grado or Sennheiser headphones.
At that time as bass player I wasn’t listening to a lot of bassists stuff since I didn’t wanted to be influenced by other players’ style and thanks to a good degree of ignorance I went down the Grado path ended with a GS1000. A good headphone for sure but laking in many aspects that have become more and more relevant to me as a listener.
What if I went the Sennheiser path instead?
Groving as an headphone listener I did myself that question time and again.
Recently I had a kind of a “sliding doors” opportunity and the chance of experience my “what if”.
A customer deleted his order at the local store where I repair turntables and I had the opportunity to buy a HD660s for less than €200.
I’ve listened to these headphones many time in the store in the last year but as for many of us my question was: “How will the HD660s sound at home?”.
When I am out whatever I listen to seems to sound good to me.
My brain’s looks to be hungry for new experiences and approves everything I listen to when I’m away from my usual audio chain.
I started listening to HD660s at home with my Rega turntable, my Lehamann Black Cube and Schiit Asgard 3 and after a month there wasn’t a day that I didn’t pick my Senneiser for a listen.
Many things have been written and said about these headphones.
Probably too much.
From “the best Sennheiser headphones ever” to the worst possible in 600 series I’ve read it all.
My experience with these headphones is very positive.
They deliver a kind of sound that engages me and keeps my attention focused on the music.
As much as I love my Sundara and Aeon Noire with these headphones I tend to relax and get lost somewhere in the space and at night I can fall asleep with them on my head.
With the HD660s I can experience a kind of engaging with the music that my other headphones don’t give me (or not so strong as with these ones).
I listen to music for an hour and I feel like I want to listen more time and again.
They are not the most comfortable, not the best in soundstage, not the best in dynamics but their sound involves me to a point I can focus on the music score and feel every single note, every variation in passages I know well.
A nice, punchy bass tone.
A very spot on midrange with an intimacy that gets you into the music as if you’re on the stage with the musician.
A treble sometimes is too pronounced for my tastes but that has a sense in the whole SQ.
I feel like these headphones at the moment are my end game.
Not the best headphones possible but for sure one that allows you to deeply concentrate on the music you are listening to.
I’m curious to try them with my incoming Valhalla 2.
But this is another story to be told.


Got them yesterday! it was the last piece on my local retailer. It was faulty and the right bass was blown :pensive:


I’m very saddened to read this.
I love my HD660.
I hope you will get a new one in exchange of your faulty ones.

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