Sennheiser HD660S Review (Headphone)

[solderdude]

Not really feasible passively, at least not without loosing sensitivity.
Something like this may well do what is needed when digital EQ is not an option or the Qudelix 5K.

 

[Blew]

That's very strange. Solderdude, RTINGS, Crinacle, Oratory and Amir... these five reviewers consistently show that the 660S has a warmer signature compared to their own measurements of the 600. If both headphones had new pads I really doubt the 660S had "far more clarity" unless one of the pairs had a frequency response that was very different from what's "normal" (aka it was faulty).

Where have they mentioned that?

By "clarity" I mean they are extremely detailed. I'm not referring to tonality or frequency response linearity. They are mercilessly revealing, so they sound fantastic when playing well produced tracks but can sound terrible when playing poorly produced music.

In my experience with them I have also found that, despite their lower impedance and their marketing towards mobile devices, you really need decent headphone amplification to bring out their best. I suspect this is why a lot of people don't have a good experience with them, because they haven't used them with the right equipment enough too hear their full potential. I wasn't impressed with them when listening to them on a SMSL M500 and Topping EX5, but they sound very good on the Singxer SA-1.

Amir's measurement below shows how impedance increases to 368 Ohm at the low end.

The redesign from HD650 seems to have been to lower the impedance:
View attachment 211589

 

[Mimimetal]

Hi, I ve bought this headphones for about 190€(second hand) and I would use it with my smartphone. Is a shanling up4 2022 enough? Thanks in advance for your helping

 

[IAtaman]

Hi, I ve bought this headphones for about 190€(second hand) and I would use it with my smartphone. Is a shanling up4 2022 enough? Thanks in advance for your helping

Hello! Congratulations! You got a great headphone for a great price.

Specifications of Shanling UP4 only specified output power at 32ohms which makes me think maybe they don't produce enough voltage to drive high impedance headphones like HD650S. Do you have the headphones yet - if you do, plug them in and see if it gets loud enough for you.

 

[Mimimetal]

Hi, i ve bought 660s not 650s, I haven't the headphones yet so I can t test it but I ve bought the up4 for about 50€ from Amazon and I m using it with moondrop chu

 

[IAtaman]

Hi, i ve bought 660s not 650s, I haven't the headphones yet so I can t test it but I ve bought the up4 for about 50€ from Amazon and I m using it with moondrop chu

Oh. My bad. 660S is a great headphone as well though.

I found online that it can output 1.7V. Not sure how reliable that data is but looks like you will mostly be fine.

 

[Wicky]

Hi, i ve bought 660s not 650s, I haven't the headphones yet so I can t test it but I ve bought the up4 for about 50€ from Amazon and I m using it with moondrop chu

I've got the 660S, it's only 150 ohms, I find it runs acceptably from an iPhone with the standard apple usb-c dongle

 

[Mimimetal]

I m considering the apple dongle a2049 but I live in Italy and i can order it only from USA. It wil cost about 20€ shipping included, worth it? If it is relevant my phone is a oppo find X3 neo

 

[Wicky]

I m considering the apple dongle a2049 but I live in Italy and i can order it only from USA. It wil cost about 20€ shipping included, worth it? If it is relevant my phone is a oppo find X3 neo

it's a pretty good little unit with a convenient form-factor, measurements here: https://www.audiosciencereview.com/...pple-vs-google-usb-c-headphone-adapters.5541/
You definitely get better measuring devices with a more power for not a whole lot more money e.g. Shangling UA1 or UA1S

 

[Mimimetal]

I read on shanling website that balanced output 2,5mm is 2,3v /32ohm 165mw. I could use this adapter https://amzn.eu/d/2NXEpde

 

[Wicky]

I read on shanling website that balanced output 2,5mm is 2,3v /32ohm 165mw. I could use this adapter https://amzn.eu/d/2NXEpde

The UA1 and UA1S as 3.5mm single ended, to the standard 3.5mm SE cable adaptor that comes with the HD660S will work. If you wanted balanced you'll need to pay a bit more... the same brand, the UA2 (~$85) has a 4.4mm balanced, which you also have with the HD660S.
Myself, I tend to use this https://www.hidizs.net/products/hidizs-s9-balanced-single-ended-mini-hifi-dac-amp

 

[Mimimetal]

I referred to up4 https://en.shanling.com/product/422
I d prefer a Bluetooth device

 

[Wicky]

I referred to up4 https://en.shanling.com/product/422
I d prefer a Bluetooth device

yeah, that will work

 

[soundwave76]

Sennheiser now sells these refurbished 199€ with a guarantee. Had to order a pair.

Outlet | Sennheiser Germany

Discover outlet products at reduced prices - tested, checked, and thoroughly inspected to meet the same high-quality standards as our new products.

www.sennheiser-hearing.com

 

[soundwave76]

Any pro tips here for softer pads? The stock ones are quite firm and start to hurt my ears with the eyeglasses.

 

[Mimimetal]

Any pro tips here for softer pads? The stock ones are quite firm and start to hurt my ears with the eyeglasses.

I have sold them also for uncomfy, above all when I m wearing reading glasses. Consider also that mine has been used for above 4 years by first owner

 

[Tallulah]

Any pro tips here for softer pads? The stock ones are quite firm and start to hurt my ears with the eyeglasses.

I would recommend lowering the clamping force by bending the headband. There are some tutorials out there since it's the same for many headphone models (600, 650, 6XX...).

I did this to my HD 600 and I'm very happy with it, much better comfort now. Just make sure that you only put pressure on the metal, not on the plastic!

Here's a tutorial:

 

[bodhi]

I would recommend lowering the clamping force by bending the headband. There are some tutorials out there since it's the same for many headphone models (600, 650, 6XX...).

I did this to my HD 600 and I'm very happy with it, much better comfort now. Just make sure that you only put pressure on the metal, not on the plastic!

Here's a tutorial:

Modified this way HD600 is by far the most comfortable headphone I have. You can have the clamping force tuned perfectly so that seal is good and still you don't feel them at all. The only downside is that you might feel guilty not using your "better" headphones as much, just because of worse comfort.

 

[aliaksej]

hello, audioscientists. Bought HD 660s from Thomann. Wonderful headphones. But noticed that pads are differently installed and are of different height from different sides. Is that normal for new headphones?

 

[Berwhale]

hello, audioscientists. Bought HD 660s from Thomann. Wonderful headphones. But noticed that pads are differently installed and are of different height from different sides. Is that normal for new headphones?

The pads are angled and are thicker at the back than the front. You may need to remove and rotate one of your pads by 180 degrees.

*edit* Actually, i'm not sure that come angled, mine are now after 3 years of use! I have the <2021 pads, so I think the front part of the pads has compressed more than the back. Comparison of older vs newer pads here: https://www.audiosciencereview.com/forum/index.php?threads/new-sennheiser-pads-measured.24845/

Video showing how to remove and replace the ear pads here...