[MattV0822]

https://en-us.sennheiser.com/headphones-audiophile-high-end-hd-660-s

Price: $499.95 USD

Technical Data
Impedance - 150 Ω
Connector - Stereo jack plug, gold-plated 6.35 mm, unbalanced, 3-pin 4.4 mm, balanced, 5-pin Frequency response - 10 – 41,000 Hz (-10 dB)
Sound pressure level (SPL) - 104 dB at 1V 1kHz
Ear coupling - Over-ear (circumaural)
THD + N, total harmonic distortion and noise - < 0,04% (1 kHz, 100 dB)
Transducer principle (headphones) - Dynamic, open
Weight w/o cable - Approx. 260 g (without cable)

A new audiophile versatility
The new HD 660 S lets you enjoy sophisticated audiophile sound in even more listening situations. The successor of the legendary HD 650 excels with the improved performance of its new transducer design. Thanks to its lower impedance, it delivers reference-class sound also when connected to hi-res mobile players, thus offering much greater versatility. The HD 660 S is an elegantly designed piece of high-quality engineering that indulges the demanding listener with aural precision and great wearing comfort.

Sound for the passionate music enthusiast
Made for the demanding listener, the HD 660 S surpasses the exceptional performance of its predecessor, the legendary HD 650. With a crisp bass, excellent mid-frequency response, and a gentle, pleasantly natural treble, the HD 660 S has an expressiveness that immerses you in every emotion and nuance of music. Still, it always stays exceptionally accurate and transparent.

Cutting-edge Sennheiser technology
The HD 660 S features a new transducer design developed by Sennheiser. This results in improved control of the diaphragm movements thanks to a specially manufactured precision stainless steel fabric, which is adapted to the contour of the diaphragm. Extremely light aluminum voice coils ensure the highest impulse fidelity. The transducers are carefully selected and paired by hand to ensure consistently narrow (±1 dB) tolerances.

Supreme connectivity
The HD 660 S has been created to enjoy music in supreme quality and from many different audio sources. Thanks to its low impedance it also offers reference-class fidelity with hi-res mobile players. Naturally, the HD 660 S reveals its full potential when it is connected to the balanced outputs of a dedicated headphone amplifier such as the HDV 820 or to the balanced output of a mobile digital audio player. Accordingly, it comes with a choice of cables for just about any occasion. All cables are made of highly conductive OFC copper, featuring very low handling noise and sturdy para-aramid reinforcement.

Designed for high-end comfort
Everything about the HD 660 S makes listening a pure pleasure – not least its strong yet lightweight open construction. The elliptical ear cups are shaped to follow the anatomy of the ear, while thick padding on the headband and the replaceable ear cushions guarantee hours and hours of listening in supreme comfort.

 

[Schwibbles]

To me, that frequency response makes it look more like the midrange of the HD600, the treble of the HD650, and a little added sub bass. If that's true, I see this being more of a HD600 successor.

I personally preferred the HD600 to the HD650 because I did not want the mid bass hump of the HD650. With the HD660S, I don't see that hump.

My two biggest complaints about the HD600 would be the resolution and the somewhat shallow pad depth. If both of these things are better on the 660, it may be worth buying (for me). I guess I'll just have to wait until there are more reviews/impressions out.

 

[mks100]

The Website says it includes a Balanced "5 Pin" Cable? Anyone know what adapter I would need for a 4 Pin XLR for my Jotunheim? I am not familiar with any 5 Pin Balanced connectors. Thank you.

 

[AxelCloris]

I'm going through some images we took of the Sennheiser HD 660 S and I figured I'd post a couple photos that show the new pads.

Here are two normal photos of the HD 660 S and one next to the HD 650 (click on the images to see larger sizes):


And here are the same images with the shadow levels pushed to accentuate the "scoop" of the new pads (click on the images to see larger sizes):

Spoiler

In the first image, you might notice that the HD 650 (left) has a more rounded pad while the HD 660 S (right) has a flatter, more angled slope on the inside. As Jude mentioned in his post, the HD 660 S's pads feel more spacious than the HD 650's. While this could also be due to a lower clamping force of the headband, I'm sure the new angle on the inside of the pads are making a noticeable difference in comfort.

I don't know about everyone else, but I also love the HD 660 S's new embossed grills.

 

[TWerk]

So this explains the hd6xx!! Finally!

 

[phthora]

I would have bought a pair of these just for the improved styling. These are IMO the handsomest of the Sennheisers. And yes, I love the embossed grills too.

 

[trybeingarun]

The Website says it includes a Balanced "5 Pin" Cable? Anyone know what adapter I would need for a 4 Pin XLR for my Jotunheim? I am not familiar with any 5 Pin Balanced connectors. Thank you.

I think the 5 pin cable was built to serve both in balanced & single ended mode, if i'm not wrong. It basically has left+, left-, right+, right-, ground and depending on the amp's socket (not our current trs or balanced) it can support either single ended or balanced.

 

[XERO1]

The Website says it includes a Balanced "5 Pin" Cable? Anyone know what adapter I would need for a 4 Pin XLR for my Jotunheim? I am not familiar with any 5 Pin Balanced connectors. Thank you.

This is referring to the 4.4mm Pentaconn balanced cable that comes with the HD 660S.
IFAIK, there are no 4.4mm-to-XLR4 adapters that are currently available (Sennheiser really should have included one). So if you want to use your Jot's balanced output, you'll still have to buy an additional XLR4 cable.

 

[castleofargh]

please, get a FR with the pads switched.
even better would be with the drivers switched if they happen to have identical mounts. to see the driver's impact, but also to see a little what the changes on the back are doing to the FR. and of course personally I'm mostly curious about distortion levels in the low end. it's one aspect where the 650 could really improve.
so far I was fully determined not to care about this headphone, but the idea of a slightly roomier pad got me interested, my ears aren't growing smaller.

 

[Solrighal]

...my ears aren't growing smaller

Are they growing bigger? How big? Photos?

 

[DoctaCosmos]

and Just today I finally got an hd600 after all these years. Poop

 

[castleofargh]

Are they growing bigger? How big? Photos?

ears keep growing. it's like 1cm in half a century but it's happening ^_^.
I don't have impressive ears sorry. a big head all over, but my ears are nothing special in context. it's just that there is no HD650 XL. you were already planning to put me in a cage along with the bearded woman, the child wolf, and the smallest giant in the world, but I saw through your plan. (it's not because I'm paranoid that they're not all after me).
honestly I do find a placement that's comfy for hours on with the 650(else I would have dumped it long ago), but I don't have that much latitude before some part of the pads start poking my ear and slowly put pressure on it. so I wouldn't spit on a little more room.

 

[ithilienrp]

The frequency response looks good, and a driver "based-on" HD700 isn't a bad idea. That driver technology/line deserved better usage/exposure. And the "upgraded HD650" seems to be better position than "downgraded HD800" (while not really official stance and many might not feel that way, at least this is what many other people perceived), IMHO.

The matte black finish, though, interests me more than the frequency response and the driver

I like the HD650, and I should be getting one of this.

 

[Hooster]

and Just today I finally got an hd600 after all these years. Poop

Me too, pretty much. Don't be annoyed. The 600s are great cans. Just enjoy them and don't go running after the next great thing. Look on the bright side. The price of 660 will surely come down after a few years.

 

[Me x3]

From the FR measurement, it seems to be an HD650 with less bass and less treble.

Less bass could be considered a fine move for a reference headphone, but less treble... I'm not entirely sure about that one.
Dialing the bass down like that makes the headphone drier and more upfront, they've probably toned down the treble as well to preserve a relatively 'soft' presentation.

It's quite curious that while many companies are going v-shaped, Sennheiser is going n-shaped.