[Pedro Oliveira]

Had the chance to spend around 10 minutes with the HD660's on the Sennheiser Hdv820 using the balanced pentacon connection. Source was flac via USB from my Android. They put a stupid-smile on my face straight away - mainly because they do everything the HD650 does, and then some. They have DETAIL in the treble, punchy bass, and THAT mid-range we all know and love. Comfort-wise they're pretty much exactly the same, the pads maaaay have been a bit thicker? There was also an HD800s connected to the same amp via 4-pin XLR, meaning I could A/B test them directly. What amazed me was how well the 660s managed to keep up on terms of sparkle, whereas the 650 politely drops away at the top end. The soundstage was unsurprisingly less, but seemed on-par with the 650's.

These are going to be a bona fide smash hit, and I'll be getting a pair immediately. I didn't realise they were only 150ohm impedence until now know, so still think my 650s will be seeing plenty of use with my Crack and Speedball.

How did it compare in terms of sub bass with the hd650?

From your description it truly seems like a very good blend between the hd600 and 650. I do not doubt they will become a hit but the price will have to drop a bit before that. At their msrp you can basically buy both the hd600 and 650 new.

 

[Mightygrey]

How did it compare in terms of sub bass with the hd650?

From your description it truly seems like a very good blend between the hd600 and 650. I do not doubt they will become a hit but the price will have to drop a bit before that. At their msrp you can basically buy both the hd600 and 650 new.

Hard to say without a direct comparison, but it had plenty of impact and slam. IMO the bass of the HD650's is just great already.

 

[Pedro Oliveira]

Hard to say without a direct comparison, but it had plenty of impact and slam. IMO the bass of the HD650's is just great already.

The hd650 has much more bass impact and slam than the h600? I was really set to buy a hd650 because despite loving my hd600s i always felt like i needed a tiny bit fuller and richer bass without sacrificing the rest of the h600 qualitys and presentation.... and then the hd600s was anounced.... now i feel like i should wait a bit for the reviews to come out. You hd650 is a older version or a silver driver one?

 

[erics75]

Is it me or does this seem like an hd700 driver? 150 ohm, more treble, even the profile of the driver behind the cover looks similar to the hd700's. Just something to ponder.....

 

[kman1211]

Is it me or does this seem like an hd700 driver? 150 ohm, more treble, even the profile of the driver behind the cover looks similar to the hd700's. Just something to ponder.....

Definitely uses a similar capsule design but the tuning is likely different and the drivers are placed notably closer to the ear than on the HD 700.

 

[Lourens]

Just as I was about to buy the 650's! Thanks Sennheiser!

 

[Evshrug]

Definitely uses a similar capsule design but the tuning is likely different and the drivers are placed notably closer to the ear than on the HD 700.

Whatever driver is in the HD 660 S, it definitely sounds distinct from the HD 700 and HD 650.

 

[Evshrug]

Had the chance to spend around 10 minutes with the HD660's on the Sennheiser Hdv820 using the balanced pentacon connection. Source was flac via USB from my Android. They put a stupid-smile on my face straight away - mainly because they do everything the HD650 does, and then some. They have DETAIL in the treble, punchy bass, and THAT mid-range we all know and love. Comfort-wise they're pretty much exactly the same, the pads maaaay have been a bit thicker? There was also an HD800s connected to the same amp via 4-pin XLR, meaning I could A/B test them directly. What amazed me was how well the 660s managed to keep up on terms of sparkle, whereas the 650 politely drops away at the top end. The soundstage was unsurprisingly less, but seemed on-par with the 650's.

These are going to be a bona fide smash hit, and I'll be getting a pair immediately. I didn't realise they were only 150ohm impedence until now though, so still think my 650s will be seeing plenty of use with my Crack and Speedball.

This is one of my dudes from the "Willy Wonka and the Sennheiser Factory" event, right? High five!
To me, it felt like the clamping force was lighter, and the earpads were less round donuts and more bowl-shaped. How much output impedance is on the Crack? Because the HDV 820 sounded great with the HD 660, and that has a 40 Ω output impedance. The pleasing result might be good for thought...

 

[endgame]

Whatever driver is in the HD 660 S, it definitely sounds distinct from the HD 700 and HD 650.

Since you’ve heard it, could you please elaborate more on its sound qualities?

 

[Evshrug]

Since you’ve heard it, could you please elaborate more on its sound qualities?

We'll see, I have to get on a plane now, last leg in returning from Germany and Sennheiser's headquarters.

 

[kman1211]

Whatever driver is in the HD 660 S, it definitely sounds distinct from the HD 700 and HD 650.

I am pretty set on getting these when I can, most likely around Christmas. Definitely want to see more impressions and some measurements. Dampening and housing design has a massive effect on a drivers sound and honestly probably just takes some design elements from the HD 700, just because it looks similar or even the same, doesn't mean it's the same.

 

[pietcux]

I placed an order as soon as it was available in the Sennheiser Germany shop. To be able to compare them, I listen to the HD650s exclusively until the HD660S arrives. So far no shipping information available, I hope on mid next week now.
@Eveshrug: Nice to know that you are with Sennheiser now, good luck for the future.

 

[Mark Up]

650/600 is semi open. 660s picture shows true open as 800/800s.

No, the above headphones are all true-open. A little fabric or foam on the outside doesn't make them semi-open. Philips Fidelio L1 / L2 is an example of a semi-open.

The hd650 has much more bass impact and slam than the h600?

These are very similar in the lower mids (kind of thin to me but many say warm). The 650 has a bit less higher mids and highs than the 600, but is still called "veiled". Personally I find the treble level perfect on the 650 but I'm treble-sensitive. The 650 has a touch more sub bass extension but is still weak in that area. I'm now highly interested in hearing how the 660 S does in that regard. If they could make a 670 that is truly semi-open/ vs. fully-open, it could deliver more much needed sub bass.

 

[cthomas]

Why are these cheaper in the US compared to Australia? No fair

 

[Evshrug]

I placed an order as soon as it was available in the Sennheiser Germany shop. To be able to compare them, I listen to the HD650s exclusively until the HD660S arrives. So far no shipping information available, I hope on mid next week now.
@EvShrug: Nice to know that you are with Sennheiser now, good luck for the future.

Thanks pietcrux! Now you know why I've been posting a lot less. I'm not a mover or a shaker in the company (yet?), but we'll see what influence I and a lot of Head-Fi trends and research can have on Sennheiser

Since you’ve heard it, could you please elaborate more on its sound qualities?

So, as a biased source (freelance employee), I don't want to hype you with my subjective impressions. And I don't have measurements on-hand to quantify "how much." All that said, there have been reductions in THD, reductions in clamping force, the included 4.4 mm Pentaconn balanced cable as well as the 6.35 mm unbalanced cable (common receiver/guitar sized 1/4" plug) means there are more connection options included in the box, and relaxing the power requirements will let more setups (with low-distortion amps) have a non-bottlenecked experience. We had some portable music players of different brands in the Headquarters' listening room, and I saw a lot of toe-tapping, head-bopping, and the occasional lost-in-listening faces in there. I don't have hype for you... just confidence that community impressions will put the HD 660 in a good light above the legendary HD 650 and HD 600.

I am also greatly looking forward to impressions on Sennheiser's newest "baby."