[Plieb]

Can anyone comment on the efficiency of the S2 sound vs the 660S, vs 650? On my singxer amp the 660s has plenty of headroom but my 300 ohm 650 has some problems especially on low recordings.
I heard someone say that it's more efficient than 650 but less efficient than 660s.
To what degree?

 

[Mike F]

BTW @Rob80b, just wondering how you're getting on with the HDVD800? off topic, but at least it's Sennheiser! I suspect that the Senns have good synergy with it, but how would you say it compares to the Bryston, both with the S2 and your other cans?

And........ back on topic, which would you say you ultimately prefer, the S2 or the 800S? And which would you say is ultimately 'better'. (That might be different from your preferred headphone Or not........!)

 

[Rob80b]

How is the sounding depth on the hd660s2 in comparison with the hd800? Sometimes I wish my 6xx to be less flat. Though it is not as bad as on some planar wall-of-sound. Tks

Obviously depends on the recording and ancillary equipment, but the presentation is different between the two phones. The HD800/S presents more of a dome where usually stage is at arms length, not always but the S2 starts off more intimate and then expands out, quite wide in fact with good layering and depth... definitely anything but flat....IMHO leaps and bounds over the HD600/650s.
Still the imaging, definition and separation prowess of the HD800/S is hard to be beat, so can be more dexterous technically.

 

[Rob80b]

BTW @Rob80b, just wondering how you're getting on with the HDVD800? off topic, but at least it's Sennheiser! I suspect that the Senns have good synergy with it, but how would you say it compares to the Bryston, both with the S2 and your other cans?

Interview time. : )
The HDVD800 is working out fine, with competent designed solid state amps it's hard sometimes to discern any obvious differences but both the Bryston and Sennheiser do a really good job with both phones. The little SMSL HO100 I also have on hand, although super clean with lots of volume isn't quite capable of reaching the same level, the BHA-1 and HDVD800 reproducing more natural and richer harmonics and bass digs deeper and more authoritative, believe it comes down to their ability to better power 300 ohm phones.
The Bryston, though, powering the HD800S I find is just so slightly more palatable,warmer/organic?
Should also mention that the more efficient HD660S performed more or less the same with either the HO100 or BHA-1 and the differences between the HD660S and S2, while evident, were less pronounced..

And........ back on topic, which would you say you ultimately prefer, the S2 or the 800S? And which would you say is ultimately 'better'. (That might be different from your preferred headphone Or not........!)

To quote myself. ...

Obviously depends on the recording and ancillary equipment, but the presentation is different between the two phones. The HD800/S presents more of a dome where usually stage is at arms length, not always but the S2 starts off more intimate and then expands out, quite wide in fact with good layering and depth... definitely anything but flat....IMHO leaps and bound over the HD600/650s.
Still the imaging, definition and separation prowess of the HD800/S is hard to be beat, so can be more dexterous technically.

 

[Rob80b]

Can anyone comment on the efficiency of the S2 sound vs the 660S, vs 650? On my singxer amp the 660s has plenty of headroom but my 300 ohm 650 has some problems especially on low recordings.
I heard someone say that it's more efficient than 650 but less efficient than 660s.
To what degree?

Don't know the SA-1 at all but it looks like a really nice and competently designed Class A amp.... I like!



The S2 being 300 ohm may sound fine but like the 650 will not reach their full potential if not powered accordingly.
But the amp looks more than capable, what is your source and are you running it balanced to the SA-1 which should double the power to the phones.

Just to add after a little Google.
https://www.audiosciencereview.com/...xer-sa-1-review-balanced-headphone-amp.23365/
"Singxer SA-1 Headphone Listening Tests
With my Sennheiser HD-650 and its balanced cable, the SA-1 was able to drive it cleanly to insanely loud levels. I am talking full skull resonances for the 1/10th of a second I could tolerate to push it up there!!!"

 

[Plieb]

Don't know the SA-1 at all but it looks like a really nice and competently designed Class A amp.... I like!



The S2 being 300 ohm may sound fine but like the 650 will not reach their full potential if not powered accordingly.
But the amp looks more than capable, what is your source and are you running it balanced to the SA-1 which should double the power to the phones.

Just to add after a little Google.
https://www.audiosciencereview.com/...xer-sa-1-review-balanced-headphone-amp.23365/
"Singxer SA-1 Headphone Listening Tests
With my Sennheiser HD-650 and its balanced cable, the SA-1 was able to drive it cleanly to insanely loud levels. I am talking full skull resonances for the 1/10th of a second I could tolerate to push it up there!!!"

I'm running single ended input at 2 volts utlizing balanced output. Gain is obviously set at high. Singxer has been criticized a bit for having a lower than usual maximum gain.
I think 11db.
Yes i realize that going balanced input at 4 volts would make a big difference but im not ready to make that move.
So i was hoping that s2 was a bit easier to run than 650 even though the impedance is the same.
Still up in the air about purchasing Neumann or the S2. Will be one or the other.
I should also mentiom i have the full class A Rebel amp which even at 1 watt worked better than the Singxer via 650. With the Rebel (2 volt dac)in high gain it will blow your ears off with the 650.
I do love sennheiser house sound but since i have 2 600 series versions i thought it may be a wise move to go with the Neumann's. However S2 is very tempting.

Very conflicted! Lol

 

[Rob80b]

I do love sennheiser house sound but since i have 2 600 series versions i thought it may be a wise move to go with the Neumann's. However S2 is very tempting.

Unless there is somerthing that is missing for "you" with your "2 600 series versions" the Neumann might be more fun and a complimentary addition, just saying' : )

 

[equalspeace]

I want someone else to pop the S2 driver in their 650 for some confirmation on what I'm hearing.

I'm in heaven with this set up. I guess that's all that matters ha

 

[IXOYE]

Listen to this ideally on Tidal or at least something like Spotify:


I've always loved that track to benchmark headphones, and I'm pretty sure that the 660S2 actually presents the most natural and overall balanced signature of all the hp's I've tried so far - Now given this is mainly from memory and it's a big statement, but every headphone in the end had something that bothered me personally (expect the 58x's, despite having a slight "veil" compared to the S2's imo). I do not think there is anything negative which will come up here, also since the longevity itself has been proven over decades now.

At this point I'd really only love to try a 660S3 or a 670 or whatever some time in the future if it ever comes out, now I'm convinced even more that Sennheiser just has the overall knows what balance is and if these small driver changes already had such an impact in the S2's then I'm excited for what's coming next. Until whenever, I'll be more than happy with these. What a blessing.

I have never heard this before, sounds incredible on 800s too

 

[Mike F]

Unless there is something that is missing for "you" with your "2 600 series versions" the Neumann might be more fun and a complimentary addition, just saying' : )

I won't be any fun for him when he hears the difference and feels compelled to come back here and tell everyone about it!

 

[gimmeheadroom]

Can anyone comment on the efficiency of the S2 sound vs the 660S, vs 650? On my singxer amp the 660s has plenty of headroom but my 300 ohm 650 has some problems especially on low recordings.
I heard someone say that it's more efficient than 650 but less efficient than 660s.
To what degree?

The 600/650/6XX are essentially identical in efficiency and impedance.

The 660S is much easier to drive, it was probably intended to work with portable devices.

The 660S2 is rated 300 ohm impedance but 104 dB/mW which is somewhat more than 6X efficient than the 600/650/6XX as rated.

I would expect that if you're not happy with your 650 out of your Singxer the 660S2 will be borderline.

 

[pietcux]

the slightly recessed vocals,

I still fail to notice this one, to me it is inaudible.

Absolutely worth listening to on this headphone. Nice how her voice matured over time.

 

[Rob80b]

I still fail to notice this one, to me it is inaudible.

Absolutely worth listening to on this headphone. Nice how her voice matured over time.

Sounds pretty good hear here. : )
Compared to my HD800S and the HD630VB which are both sounding more recessed... and for my personal preferences the S2 could be even a little less intimate.
Overall though the recording is IMHO pretty good. Thanks

 

[sebiambrus]

Sennheiser HD660S2 arrived 1 hour ago... we will se how it compares on its own amp with the older brother..

after 2 day non stop listening , i can make some first impressions;

After owning almost all TOTL hp and almost all mid fi HP . IMHO this HD660S2 sound is the most close to lifelike sound presentation. It is a totally natural sound for my ears, no need to EQ. I sometimes go to Jazz Clubs and Opera life concerts and imho the HD660S2 is the most close presentation to them. Also I am a guitar player and I know how the guitar sounds in my hand when I am playing, the HD660S2 gives the same tonality and naturalness without coloring the sound. The HD660S2 has the Sennheiser house sound signature with the best tonality from their headphones.

It is a much more speedy driver than the older HD6 series. I think the transient speed almost reaches HD800 levels which gives a nice flow to the sound. The whole freq spectrum is super clear but it does not have spikes for my ear . Honestly this is the first pair of HP which I used 6+hour sitting in a row without getting ear fatigue. So tonality is spot on.

The low freq and dynamics are MUCH better than the old Hd600 and HD650 . it is almost focal clear lvl or dynamics and bass but with much better tonality.

Technical vise I hear all details but not as spread out like the hd800 and not as micro details but for listening music and NOT analyzing the HD660S2 gives much better listening experience .



Vs Focal Clear MG : the Mg got the lead on technicalities (but not much) and trades some tonality to dynamics, therefore the MG got more bite but more artificial sound it got this aggressive metallic sound in the upper freqs . The HD660S2 found the sweet spot in technical vise and tonality the HD660S2 gives much more lifelike sound , ( i mean what you hear in live concerts with your own ear ) honestly it is more lifelike which is i think the most important for me.



Meze 109 Pro: Honestly the meze is a super colored sound with aggressive treble and lacking technicalities and booming bass. For my ears the Hd660S2 got better speed, more flowing sound, more transparent AND super natural sound vs the ultra colored sound of the meze. The meze got a bigger soundstage, however the HD660S2 gives better depth z axis. The Meze got boosted bass and a really spicy treble (which is good for half -1 hour listening but after that I realized that mezes aren't for me due massive coloration).



hd600: Imho the HD660S2 improves everything for me TONALITY TOO. The hd660S2 has better speed, more details, more slam, more transparency , better soundstage, better depth...

HD650: same for sound.

(maybe the revieves are deaf or not listen lifelike music i do not know, if they say that the HD660S2 is not a step up from the existing hd6 lineup...))



Hifiman Arya Stealth: Well you can kill me for this. But for me the Hifimans got this plastic timbre which kills the naturalness of the sound. The HD660S2 has a better listening experience, better dynamics , and much lifelike sound. The Arya got a much bigger soundstage, (almost Hd800) the Arya got better micro details, more extended in both ways but it sounds like a plastic bag vs the Sennheiser house sound. Also the dynamics is non-existent on the Hifimans. ( the transient speed is better on the Arya obviously but this not gives dynamics to the sound)



I used Sennheiser OWN amp (HDV820) for most of the listening with my HD660S2. So maybe that's why I got these good impressions. I believe the Sennheiser guys tested the hp in this amp ( I know it has high output impedance which can alter the sound but they engineered it for the HD800S to give some slam and 3 d effects to the hd800 series ) . I also listened to my OTL dual mono tube amp which was really good paired with via chord dac (mojo2) (the OTL tube amps got extreme high output impedance which can alter sound). I am not an ASR guy. I just know as a musician how the live music sounds.



The negatives: cheap paper box, it has the same build q as a NEW hd600. My older hd650 which was made in Ireland got a premium feel and plastic in it, this new plastic in the Hd6.. line up gives this cheap feeling . (it not alters the sound but feels cheap in the hand )

Also when i Opened the box the cable which was installed to the hp ,6,3mm, was badly bent near the connectors . Obviously the hp can be damaged without a proper box in transportation. it is a negative. Also when I opened the box it was not a good experience . I remember when I opened my first old HD650 a long time ago and it gave me that satisfying unbox therapy feeling. Now opening the HD660S2 box for the first time gives a disappointment after I owned a lot headphones.

 

[chesebert]

after 2 day non stop listening , i can make some first impressions;

After owning almost all TOTL hp and almost all mid fi HP . IMHO this HD660S2 sound is the most close to lifelike sound presentation. It is a totally natural sound for my ears, no need to EQ. I sometimes go to Jazz Clubs and Opera life concerts and imho the HD660S2 is the most close presentation to them. Also I am a guitar player and I know how the guitar sounds in my hand when I am playing, the HD660S2 gives the same tonality and naturalness without coloring the sound. The HD660S2 has the Sennheiser house sound signature with the best tonality from their headphones.

It is a much more speedy driver than the older HD6 series. I think the transient speed almost reaches HD800 levels which gives a nice flow to the sound. The whole freq spectrum is super clear but it does not have spikes for my ear . Honestly this is the first pair of HP which I used 6+hour sitting in a row without getting ear fatigue. So tonality is spot on.

The low freq and dynamics are MUCH better than the old Hd600 and HD650 . it is almost focal clear lvl or dynamics and bass but with much better tonality.

Technical vise I hear all details but not as spread out like the hd800 and not as micro details but for listening music and NOT analyzing the HD660S2 gives much better listening experience .



Vs Focal Clear MG : the Mg got the lead on technicalities (but not much) and trades some tonality to dynamics, therefore the MG got more bite but more artificial sound it got this aggressive metallic sound in the upper freqs . The HD660S2 found the sweet spot in technical vise and tonality the HD660S2 gives much more lifelike sound , ( i mean what you hear in live concerts with your own ear ) honestly it is more lifelike which is i think the most important for me.



Meze 109 Pro: Honestly the meze is a super colored sound with aggressive treble and lacking technicalities and booming bass. For my ears the Hd660S2 got better speed, more flowing sound, more transparent AND super natural sound vs the ultra colored sound of the meze. The meze got a bigger soundstage, however the HD660S2 gives better depth z axis. The Meze got boosted bass and a really spicy treble (which is good for half -1 hour listening but after that I realized that mezes aren't for me due massive coloration).



hd600: Imho the HD660S2 improves everything for me TONALITY TOO. The hd660S2 has better speed, more details, more slam, more transparency , better soundstage, better depth...

HD650: same for sound.

(maybe the revieves are deaf or not listen lifelike music i do not know, if they say that the HD660S2 is not a step up from the existing hd6 lineup...))



Hifiman Arya Stealth: Well you can kill me for this. But for me the Hifimans got this plastic timbre which kills the naturalness of the sound. The HD660S2 has a better listening experience, better dynamics , and much lifelike sound. The Arya got a much bigger soundstage, (almost Hd800) the Arya got better micro details, more extended in both ways but it sounds like a plastic bag vs the Sennheiser house sound. Also the dynamics is non-existent on the Hifimans. ( the transient speed is better on the Arya obviously but this not gives dynamics to the sound)



I used Sennheiser OWN amp (HDV820) for most of the listening with my HD660S2. So maybe that's why I got these good impressions. I believe the Sennheiser guys tested the hp in this amp ( I know it has high output impedance which can alter the sound but they engineered it for the HD800S to give some slam and 3 d effects to the hd800 series ) . I also listened to my OTL dual mono tube amp which was really good paired with via chord dac (mojo2) (the OTL tube amps got extreme high output impedance which can alter sound). I am not an ASR guy. I just know as a musician how the live music sounds.



The negatives: cheap paper box, it has the same build q as a NEW hd600. My older hd650 which was made in Ireland got a premium feel and plastic in it, this new plastic in the Hd6.. line up gives this cheap feeling . (it not alters the sound but feels cheap in the hand )

Also when i Opened the box the cable which was installed to the hp ,6,3mm, was badly bent near the connectors . Obviously the hp can be damaged without a proper box in transportation. it is a negative. Also when I opened the box it was not a good experience . I remember when I opened my first old HD650 a long time ago and it gave me that satisfying unbox therapy feeling. Now opening the HD660S2 box for the first time gives a disappointment after I owned a lot headphones.

Would be helpful to understand your sound profile preference, music preference and experiences with other TOTL cans (i.e., how long you had Utopia, for example).