19% of 231 verified Sennheiser HD 660S2owners don't recommend it — based on real owner comments from Reddit, enthusiast forums, and YouTube.
For balance: 61% recommend it. This page collects the complaints so you know what you're signing up for — read the full owner report for both sides. How we score
“At $250-$350 I would consider giving these a go at $600 they are a pass.”— @mindhead1 on YouTube
“I have to agree with the complaint on the box, at $600 you should be getting something way better than that.”— @Valyraen0341 on YouTube
“I'm gonna have to go with the older, equally as good model lmao”— @SzymonSaysStuff on YouTube
“I have hard time believing you that 660S2 are better than 660s yet still worse than 650”— @Father_Celeron on YouTube
“So its a less extended 6xx for almost double the price?”— @En_Joshi-Godrez on YouTube
“not really better than the 660S (and because of the big price difference… I would pay 660S”— @Zaudi_Jonas on YouTube
“I've never had a Sennheiser with a slamy punchy bass. I guess this is no exception.”— @kyron42 on YouTube
“Hearing that the bass extension isn’t as good as the anemic 6xx is disappointing to say the least.”— @sonickiller360 on YouTube
“it seems that it's not really an upgrade just a different tunning :(”— @ccdani2 on YouTube
“good, but why pay extra when you can get a 6xx/650/600 for hundreds cheaper?”— @lockjaw333 on YouTube
“Passing to 600 after a good listen with 650, it immediately sounds rough.”— @daniluzzu on YouTube
“I just dont see how this can compete at that price point with other offerings like Hifiman Edition XS”— @liam2 on YouTube
Not complaints — practical notes from owners that didn't affect the score.
“I have HD660S2, and from my experience, they benefit from proper amplification, the voltage to be exact.”— Ok-Tune-9368 on Reddit
“The 660S2 is luscious, intimate, and engaging. Excellent for intimate acoustic music or jazz.”— BurntFemboyWater on Reddit
“Cable is not boomy or rather microphonic, very silent, relatively flexible and light as well. Especially compared to the thick chungus you get with the HD800S.”— Takanaka on Audio Science Review
“My own HD660s2 didn't wear out in two years almost at all. Maybe plastic bended ever so slightly like 2%, but earpads wear was way noticeable.”— UndefFox on Reddit
“don't give it a quick listen in a store. It won't impress like some other headphones do. Give it some time and throw all kinds of music at it.”— solderdude on Audio Science Review