HD 660S2 Open‑Back Hi-Res Audiophile Headphones, Ultra‑Light Aluminum Voice Coil, Extended Sub‑Bass, 300 Ohm Impedance & Airflow Transducer, Plush Ear Cushions, Premium Comfort, 2Y Warranty

Been using for 6 months now, even with rough use its been holding up better than my gaming headphones (Logitech G pro X). It was able to run off my motherboard audio(supremefx audio chip with 9 resistors) But even with full volume it only gave out what my Dac & Amp gives in 15-20 volume Pros: long lasting comfort for my big head with ample earcup size, no matter how high the volume is, the headphones don’t crackle or cut out the sounds, you may need a appropriate Dac and amp to support these headphones (the one I use it Fiio K11 R2R). Can be run off iphone with iphone’s headphone dongle too. Cons: the size adjustment Sometimes feels very hard to adjust which in turn feels like breaking, but the build quality is insane for what its worth, and even with getting the headphone get hit or banged on table, i dont see any visible scratches after 6 months. The velour earpads need some maintenance tho If u r a bass lover, open back headphones are not for you But if you try these out, u wouldn’t want to go back to closed back or bassy headphones much

Wow ,paired with Fosi DS2 balanced output and voila! What a soundstage. Everything is perfect,I didn’t know fosi has so much details and neutral soundstage. Apple Lossless sounds like never before on iPhone 14

Amazing detail in sound. The HD820 headphones are very comfortable with moderately good sound isolation. The headphones originally had an issue with the right side driver emitting soft rattle with heavy bass frequencies. Contacted Sennheiser (Sonova India) and got a replacement under warranty. The experience with Sennheiser Service (Sonova India) was seamless. Everyone along the chain were prompt in responding & updated me on the status. The Rep assisted me by guiding me on how to send them to the service centre in Delhi. Everything went seamless. With this service experience with Sennheiser India, i now have more confidence in buying more Sennheiser products. I constantly keep track for deals on Sennheiser Headphones. Started my Audiophile Journey with Sennheiser MXW1 (World's 1st Wireless Earbuds) in 2008 and bought several Sennheiser Headphones all over the world since. No matter what country i was in i was able to find Sennheiser products easily compared to any other brand. The journey continues.

Extremely good sound quality, I have airpods pro 2, sony 1000xm5 headphones , a hyperx one .. and in pure sound clarity and quality terms , this beats all. But no ANC mode is probably the only con.

Amazing Sound, A good upgrade from HD 599. The headband can be a bit tight at first, but it fixes itself in a couple of weeks. People who liked HD 559 or 599 can expect more clarity, better soundstage, and more BASS.

I upgraded from bunch of headphones like the HD650 and the DT990 edition. The headphones build quality is good despite being lightweight, the earcups are bigger and puts less strain on someone like me who needs reading glasses. The sound is neutral type. Which means it's very good at mids if you have a neutral sounding DAC. Yes a DAC is needed since except my macbook M2 max not other device can drive it that good. The last thing is that these double as a very good gaming headset. Wish there was an option for a cable with a strap on mic like vmoda or my beyerdynamic for gaming. It's a missed opportunity I guess. Def justifies it's price.

I'm not a proper audiophile, I was using the sony 1000xm3s before this which I was really happy with. But this Sennheiser is on a different level in every aspect except outright bass. I'm Starting to understand why audiophiles spend so much money on their audio.

I use many wireless Bluetooth headphones from Bose and Sony. First time I’m trying to understand the Hi-Res headphones, definitely there is a noticeable difference when I listened first time with this Sennheiser HD660S2. But this needs an Amplifier/DAC, without amp/dac it’s not good, not portable like any other wireless headphones. I’m happy I bought this headphones, it’s amazing to listen some of the Hi-Res tracks.