🔶 Sennheiser HD660s

This is the official thread for the Sennheiser HD660s. This thread is for discussion and reviews.

  • Over Ear
  • No Amp needed
  • Open Back

:red_circle: HifiGuides Amazon link


Z Reviews




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Can I suggest corrections here? The hifiguide headphone recommend tool shows a broken review link for the HD660s. Thanks for the recommendations and info over the years Zeos.

My daily drivers, running balanced off a CMA 400i. Best 600 series cans, loses the bad and gains detail retrieval. Some like to say the 58X are as good, but they’re not. I can say this as a 58X owner. Those have a very similar sound and more (good) low end, but they aren’t as good with detail. My 660 pads are starting to get a little flat, as 600 pads do, and it does affect the sound just like other 600s. Plan on buying new pads every year or two.

CMA 400i is a nice choice. Congratulations on this one

Had the 600 and now the 660s+58x
The new ones are the best allrounders but miss bit detail compared to 600/650 or my Beyerdynamic DT1990 Pro.
I use them from my SMSL M6 and ifi xDSD or Earstudio ES100, Fiio BTR3, Fiio Q1 II

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my dear fellow community members, i seek your help and experience!
I finally found a forum where i can ask for help choosing a very good pair of headphones!
I do not have the money or the services to try and find my suited headphones and i come to ask for your opinion: Which Hi-fi headphones should i buy if i am a BLUES enthusiast?!! (example: Gary Clark Jr, Crossroads live experience etc)
I am in the area of 500 $ price range (soon, cause now i’m saving for the near future)

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Unpopular opinion
The 660s are overpriced, not special and mechanically inferior to HD600s and HD650s
Measurements support theory but I’m sure people will still attack me personally for saying this

Also with some minor modifications that Solderdude demonstrated in his Website you can get the MD 58X J’s to sound as good as the 660s


I completely agree with you. When you put them on, the 600 and 650 are immediately smoother sounding whilst being more refined. I also find it odd that most late-20th century cans from Sennheiser and Beyerdynamic were absolutely awesome but now it seems everyone is pushing for detail and speed. Maybe all the old engineers have died. I do have to say though, the DT 1990 with analytical pads are really fantastic with a little front damping to reduce the treble mountain.

I have also tried Solderdude’s HD 58X mod in direct comparison. While they do measure pretty much identical, the 660 still retains better clarity and detail all around but the difference isn’t large.


I own 660s/58x and the 1990s
Prefer for critical listening the Beyers with analytical pads
for movies the 58x
and as perfect allrounder with less soundstage than 1990s the 660s

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Between these and the 6xx, which is a better for general purpose?

Totally agree with AFK. The 660s are overpriced and do not improve the sound enough past the 600/650 for me. Mine went back to Amazon. I also found them to be grainy and not nearly as smooth sounding in comparison to the 600/650. I’d only suggest them over the 600/650 if you were only running them off a smartphone and not a dedicated amp.

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I’d go 6xx in a hearbeat for the price savings alone. The 6xx is a fantastic headphone at an incredible pricepoint as long as you plan to drive them with a dedicated amp.

Every audiophile should own a 6xx. There’s no reason not to.


What about getting used 660S for about $270 so the price difference isn’t that much?

the 660s are on sale - 289 Euro at Amazon Germany with Prime shipping at the moment

Are they still on sale?

No. Now 379 again. But maybe get some used?

I’m afraid that my pads are wearing out, but I can’t be sure. Does anyone know how the sound changes when the pads are worn?

The pads will physically flatten when they wear out, you’ll be sure. You don’t judge by the sound, it’s the change of shape of the pads and the subsequent change in how close your ears are to the drivers that changes the sound. If your pads aren’t squished flat, usually more on the sides, your pads aren’t worn out.

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I don’t have the 660S, but having read reviews as I want a pair, it’s said that you should replace the pads at least once a year.

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I am looking to just upgrade the pads to something softer and possibly a solid sheep skin version.

Does anyone have pad makers they suggest?

I keep hearing people say the sound changes, I have never swapped pads before. Anyone have experience with pad swaps?

I am thinking about dekoni pads. Opinions?

With most if not all Sennheiser headphones, stock pads work the best and yes, sound will change. For the worst in this case.