Sennheiser HD 660S2

“They are my go-to primary headphones.”

“I am happy about the sound profil and the quality. The retail price is kind of ridiculous though”

“I wouldn't say the 660S2 is an upgrade. It's really on a similar technical level to the 600, but the tuning is quite different. I didn't like it as much as the 6XX and 600.”

“It's not just louder bass. It's more nimble, more detailed. Play a song with a fast, complex bass line, and you'll hear each note individually on the S2, while the 6XX blurs them with or without EQ.”

“I have the 660s2 and the hd800s, the soundstage is definitely better and the comfort imo is way better but in saying that I don't think it's worth replacing unless soundstage and imagining is something you really want.”

“I had the hd660s2 i was very disappointed with them... boring tone. Everything sounds the same, IMO.”

“I absolutely love the HD660S2, definitely an upgrade to the HD600”

“The 600 and 650 sounded different enough from the 800 to justify keeping them, but I got rid of the 660S2 and kept the HD800.”

“I have HD660S2, and from my experience, they benefit from proper amplification, the voltage to be exact.”

“The treble on the 660s2 isn't particularly great + with the added warmth in the low end, not so great sub bass extension and poor pricing, it's hard to recommend for me personally.”

“the S2 is my favorite of the 600 series. By a wide margin. I enjoy the added kick in the pants out of the bass performance as well as the extended upper frequencies.”

“detail retrieval is similar, 660S2 is not that much better either but 490 Pro (Plus) has even better soundstage and imaging than already good one on 660S2, I do prefer 660S2 for music”

“I have the HD660S2. They sound amazing with every genre except rock. I need more Bass. For everything else, I really enjoy listening to them. I can wear them all day.”

“Just received my 660S2'S today wow what a difference from the 6XX”

“I own both the HD660S2 and Hadenys. The Hadenys are a much cleared headphone with performance across the board. The S2 honestly sounds muffled in comparison. I vastly prefer the Hadenys.”

“only have the HD660s2:   - bass is a bit lacking which you can improve with eq   - soundstage sounds flat, but got used to it   - very comfortable for wearing all day”

“in weekend when children are at grandparents, HD660s2 are beating all of them…”

“I fiddled around with eq and made my 660s2 sound like px8 but whatever I did, it never sounded better than px8. I love rich lush mids and vocals and I returned 660s2.”

“For the headphones I own, I would rank my enjoyment as Bokeh Closed > Empyrean II = LCD-X 2021 > HD 660s2 > HD 650 > DCA E3 > DCA Noire X > HD 800S.”

“In a way it reminds me a lot of my beloved 650 but better ,enough so that I am finally selling 650 and bying 660s2.”

“I have both and I feel HD660S2 only wins marginally in treble quality. Everything else, even soundstage, sounds better to me on the 620S.”

“The proprietary plugs make the 660s2 a worse headphone lacking functionality. They aren't as a good of a daily driver as they could be.”

“I love my Sennheiser HD 660S2’s but I really really needed to run them balanced and push the BTR7 to get them to where I wanted them, given that they’re 300ohm.”

“660 S2 are great headphones!”