SENNHEISER HD 660 S - HiRes Audiophile Open Back Headphone

Ill be comparing it to the HD600 which I bought at the same time to try. TLDR: Im keeping the HD600 and returning these.

I mostly listen to classical, which sounds very detailed but warm on these. However, they also sounded great on jazz recordings from the ‘20s. What little pop and rock i’ve listened to has also sounded great. My only warning would be that if you like “in your face” headphones, these are not for you.

After 2 months of intensive use, I think Ive found the best headphone so far. Im listening different kind of music (pop, electro, accoustic live etc),you miss no detail, and there is no fatigue. Bass seems better after break in. It s not a show off sound, but a very natural, enjoyable sound. Voices are especially amazing.

The 150ohm impendence makes the 660S much easier to drive then 600/650, it has a typical Sennheiser rich and warm sound signature. Im using the balanced output of Fiio M11 to drive my 660S and it sounds amazing. The sound stage is smaller than 600/650, thus you can feel the intimacy between the singer, especially female vocals. The base is rich and warm, but in decent amount, and does not overpower the treble.

Extremely detailed sound quality and fairly lightweight too, can recommend.

I bought this after using audio technica ath-m50x for about 5 years. 660s sounds much better for me. Its kind of similar sensation I felt when I heard the sound from floor standing speakers after replacing book shelf speakers with them.

Ive been using Beyerdynamic DT990 Pro 250 OHM for almost 10 years now. I bought these 660S to upgrade my sound and comfort. After an hour or so the ear cups would start to hurt my ears on the Beyerdynamic headphones. I finally took the jump as I didnt want to spend the money, but am so glad I did. They sound fantastic and I can barely tell they are on my head. I bet they get even better after some burn in time too. As noted by others, as an open back headphone there will be a lot of sound bleed in to the room. Since I live alone this is not something I care about, however, for others it might be. 5 stars, would buy again.

Have used these for gaming, on the plane, and in the studio and they work great in every aspect. The sound is clean and crisp and the mids are very distinct and clear

Sounds great, good Bass for a pair of headphones with great mids and highs. Best headphones that I ever owned. the only minor negative is that they dont look or feel expensive although maybe they needed to keep the weight down to make them feel as comfortable as they do while wearing them.

Absolutely love these, I also own the Massdrop HD6xx and I would absolutely chose the HD660S over the 6xx. Using it with my Audio-GD NFB11.28