Sennheiser HD660s2 Open-Back Headphones - Official Discussion Thread

Not at the moment, I’m working on a big post though that might help with that.


Yes I would also like to make that comparison as I do highly enjoy the 650 sound.

For my preferences, the 600 is my least favorite, and the 650 and 660s2 are my personal favorites in the 6 series lineup especially when paired with more analytical chord gear.


I’ve had these for a little bit now and have been directly comparing to the HD 600, and yeah they’re definitely not a definitive upgrade. I tend to eq them both to a very similar target so my impressions are mostly focused on the more supjective/technical aspect.

Relative to the 600’s, the 660S2 portray a better sense of macrodynamics and the transients are faster and more clearly defined, but the 660S2 aren’t as profficient in the detail within the trailing ends of tones and the decay of stringed instruments isn’t as natural sounding IMO. Treble is ‘sweeter(?)’ sounding on the 600. I find the biggest difference to be in the bass whereby the 660S2 is better controlled and tighter. Headstage is similar enough that it shouldn’t be considered in a purchase between these headphones, perhaps the 660S2 is a hair less 3-blobby but the difference is very slight, however the image seperation is a bit better on the 660S2.

I do think the 660S2 is noticeably less grainy and coarse sounding than the 660S version 1 which is a nice improvement but if the 600 and 660S2 were at the same price I’d still pick the 600 six out of seven days of the week.


I love the way these headphones sound with guitars. That dip in 4.7k leaves a little more room for the 7-8k grit to come through in the rock tracks I’ve been enjoying.

The low end is warmer, but still not as impactful as I might like. iFi’s xBass gives it a little more excitement, which I think makes up for that gap. Overall, Im enjoying their sound signature and really like the look. The matte black and copper accent looks suuuper clean.


As one of the commentators said it is but yet another variation in the 600 series. Sennheiser is milking the cow, which is fine as long as they would stayed in the price bracket of the other models. Right now it is seriously overpriced. Personally, I also think they should have stayed with the standard naming convention and have called it HD665S or 670S. Now we are in Asian naming territory where the next model could be a HD660S2XA!

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