I purchased these headphones to be used as a check against my Adam A8H monitors and I've loved them from the moment I listened to my first song. They are clean and clear and have a great feel to them. I have some great headphones from Beyerdynamic (2 different models) which I absolutely love and several pairs of Audio-Technica's, but these are in a class of their own. Wearing them is like having a small set of monitors strapped to your head, but they are not only the lightest headphones I've ever worn, they are also perfectly balanced so when you turn your head they feel like they are part of you. I wear headphone for hours some days and these are amazingly comfortable and have experienced no ear fatigue. I don't like writing reviews but these headphones demand it.

After a year using this headphones, the sound is amazing, I have several headphones and this are my favorite ones. I know there are several headphones better than this ones, but for the price range, I believe this is the best option.

I've had these for about 6 months and absolutely love them. They are very comfortable. I can wear them for a long time without any problems. But, of course, the best part is the sound. Truly amazing. I feel like I can reach out and touch each instrument. Unbelievable clarity.

I've got a big head. And... big ears. After i ordered these headphones, I started seeing negative comments about the "clamping" issue and lots of folks complaining about how tight they are for even medium-sized heads.

Please take it from a large-headed guy, I love the feel of these phones.

And... they're a nice upgrade from my decades old HD265's!

Greetings you all. The Sennheiser HD 660S2 Open-back Headphones are the Best
Reference Headphones under $ Dollars.
We have been a Sennheiser fan for a few decades
And we Love the balance and powerful sound.
Compared to much more expensive headphones we own, the Sennheiser beats them all for the
Money they sell for.
If you buy them Please ENYOY

One of the best headset

These headphones are superb, I strongly recommend them. I own the Sennheiser HD650s and the HD660S2 easily surpass them. When EQ'd using a low shelf filter by about 5dB around 100Hz, the slam in the bass for an open-back headphone is really awesome and a massive improvement over the first generation HD660 and HD600/650. These headphones really excel at any genre of music I throw at them, whether it be classical, jazz, electronic, folk, blues, pop, rock, or alternative/indie. Somehow they sound more detailed and clear/resolving to me than the HD650s. I know this doesn't seem right based on raw FR graphs comparing the two, but the redesigned transducers and drivers seem better at detail retrieval to me. No harshness or sibilance in the treble, though. Soundstage is similar to other HD6-- models, but doesn't feel claustrophobic or narrow. Just silky smooth treble and lovely midrange for vocals with a greatly improved, tight bass response. The clamp force feels appropriate and keeps them securely on my head. I love that the included cable is shorter (1.8m) with a full-size 6.35mm gold-plated jack so I can plug it directly into my JDS Labs Atom+ DAC/Amp stack without a cumbersome adapter. To me, these headphones look and feel luxurious as well as sound superb. The bronze accents on the lovely grilles and beautiful openly-visible transducers are pleasant to look at. The velour pads and headband cushion are quite soft and comfortable. Worth the price in my opinion just for the improved detail retrieval (particularly with vocals), overall presentation, and bass extension over its predecessors in the HD6-- line. Interestingly, FR graphs show a striking similarity between the HD660S2 and the HD58Xs from Drop but these definitely sound more detailed and refined to me than my HD58Xs. These headphones easily best others in the ~$500 price range and I'd argue even sound better than some planar magnetic headphones I've tried, particularly in terms of the very refined frequency response out-of-the-box. For a dynamic driver pair of headphones, the HD660S2 are about the best you can get for the price. Sweetwater offered exceptional warranty service and customer support, so I'm confident this was a good purchase. These headphones will be my new daily drivers at my home office setup. If you are on the fence about shelling out more money for the more premium model, you really can't go wrong with this purchase. Best-in-class headphones with a relaxing just-right presentation.

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I wore out my 660S (first generation) set and replaced them with this. This is, by a wide margin, the best fidelity headphones I've ever bought. Sounds are crystal clear and comfort is at a premium. Connectivity will leave you satisfied. If you're going to be focusing for long periods of time and just want the best sound you can get at any price point, this is the set.