[tamleo]

No idea, but probably a fact checking miss from the maker of the website. From Sennheisers own posts here it should be the same driver but tuned different, different diaphragm and a new voice coil. Main differences according to Sennheiser is a lower resonance frequency and a higher impedance.

At hd650’s page it said the hp is rated at 38mm transducer and 42mm diaphragm . Only the hd660s’s page it said “42mm transducer” . So it is maybe a typo.

 

[Mike F]

At hd650’s page it said the hp is rated at 38mm transducer and 42mm diagram . Only the hd660s’s page it said “42mm transducer” . So it is maybe a typo.

But the 660S is not originally a six series driver. It was from the 700, so maybe it is different?

 

[tamleo]

But the 660S is not originally a six series driver. It was from the 700, so maybe it is different?

my bad. Only the specs of the S2 showing “38mm transducer”. I think it is just a typo and we have nothing to worry about

 

[headstef]

Hi. Does anyone know why Sennheiser website rating the hd660s at 42mm driver and the hd660s2 at 38mm?

The dimensions (diameter) of the driver have not changed. It has always been a driver with a 38mm diaphragm (moving part) in its 42mm chassis. This is mentioned as a 38mm driver in some specs or as a 42mm driver elsewhere.

 

[Rob80b]

And a separate question. Did the HD630VB precede the HD820 in that case? I had presumed that it was more recent?

The HD630VB came out in 2015, preceding both the HD660S and HD800S...the HD820 was announced in 2018.....

Nothing hanging on this except in that case the chassis for ''that'' headphone has been around for a while and presumably proven to be durable.

Hard to really get all the answers and it has never been established, and your guess is as good as mine, if the NDH20 was not just the 630 resurrected minus the variable bass and inline controls.
The 630 had a newly designed driver by Axel Grell and probably used in the NDH20, impedance is different, but they share the exact same chassis and baffle with slight modifications, and most likely still made at the Sennheiser plant in China.....so who knows. ????
A closed back HD660S2...we will have to wait and see.

 

[Rob80b]

"The can that shall not be mentioned" has different ear cups, different internal wiring (balanced), different enclosure and different driver. Not too much in common with the NDH 20 really, and even less in common with the HD630VB.

On a positive note "The can that shall not be mentioned"...may have been the incentive needed for the development of the S2.

 

[headstef]

On a positive note "The can that shall not be mentioned"...may have been the incentive needed for the development of the S2.

A month ago I wrote that maybe the 660S2 was developed under recent competition pressure (implying the Meze 109 pro and the NDH 30) but this was practically denied by @ericpalonen:
https://www.head-fi.org/threads/sennheiser-hd-660s2-thread.966685/page-124#post-17432679

 

[Rob80b]

I sincerely appreciate the enthusiasm. A few quick notes:

The HD 660S2 was actually ready last year but we pushed it to Feb '23

A month ago I wrote that maybe the 660S2 was developed under recent competition pressure (implying the Meze 109 pro and the NDH 30) but this was practically denied by @ericpalonen:

Ah ha!... so the NDH 30 was maybe influenced by the development of the S2 or call it a tie and say at the same time.

....shall this banter never cease? lol

...Your Neumann are great, nothing to worry about, nothing to prove, enjoy!

 

[pietcux]

As I work from home, I have the pleasure to listen to music most of the day. I must say the HD660S2 is made for endless listening sessions without any fatigue at least for me. Rod Stewart "Unplugged and Seated" is in my ears right now...
The HD660S2 outperforms most other cans I ever had, only the HD660S and HD650 come close.

 

[marekm]

I am totally hooked on Sennheiser

HD560s in my office, HD650 in my living room and HD660S2 in my home study (competing for my ears with Meze 109 Pro)

Needless to say S2 are my top pick

 

[Mike F]

The HD630VB came out in 2015, preceding both the HD660S and HD800S...the HD820 was announced in 2018.....

Hard to really get all the answers and it has never been established, and your guess is as good as mine, if the NDH20 was not just the 630 resurrected minus the variable bass and inline controls.
The 630 had a newly designed driver by Axel Grell and probably used in the NDH20, impedance is different, but they share the exact same chassis and baffle with slight modifications, and most likely still made at the Sennheiser plant in China.....so who knows. ????
A closed back HD660S2...we will have to wait and see.

The only thing I know for sure is that the 30 is a very different headphone from the 20, which is currently my favourite closes back.

 

[ericpalonen]

A month ago I wrote that maybe the 660S2 was developed under recent competition pressure (implying the Meze 109 pro and the NDH 30) but this was practically denied by @ericpalonen:
https://www.head-fi.org/threads/sennheiser-hd-660s2-thread.966685/page-124#post-17432679

I was listening to the 660S2 in September 2022 with final tuning -- it had been in development long before that even. Competition is good for the end-user but we do not see product development and launches as a race to market (that much should be evident by now haha).

 

[Rob80b]

Moving away from Miles Davies and Rammstein's Operas, here's a good one for showing off the dynamics of vocal expressions on the S2. Overall the S2 has an extremely well controlled driver IMHO, very noticeable in the higher vocal treble areas, have yet been able to get to trip up.
https://tidal.com/browse/album/59284867

 

[Arniesb]

Yes, swapped back. Everything is in the exact same condition. The headphones are designed to be disassembled and vice versa quite easily. I was probably more careful than the person who originally assembled them ha

Thats shameless behaviour. No wonder there are tons of complaints when people receive stuff scratched and abused when it should be pristine.
I received my hd800S when i bought it, with its box seal broken and never did and never gonna do business with that dealer again.

 

[Luckyleo]

Well, I've been pretty much lurking here since the start. I finally broke down and ordered the S2 a few minutes ago. I really enjoy the 660s, as well as the 560s, and 6xx. Thought I'd try the S2 out as I greatly appreciate the Sennheiser house sound. I'm hopeful! Thanks for the great conversations and opinions during the first 211 pages of this thread!

Leo