[RiflemanFirst]

Well, I liked the extended treble response over the 650 in theory, but not in practice. With my equipment setup, there was some peakiness (is that a word?) to the 660s treble that made me cringe. Then again, I am very sensitive to sharper-sounding treble. YMMV, but they just weren't a good match for me with my particular equipment.

Interesting. I'm not experiencing overly sharp treble with my setup, fortunately. I can understand that some people are definitely more sensitive to treble than others and that is why headphones such as the HD650 are so popular.

 

[McCol]

My experience of open headphones is fairly much zero but these sound excellent using my Mojo/Poly.
The treble seems just right to me, no spikes or harshness.

 

[Caruryn]

It really depends on the source but these are not overly smooth on the highs ,there is some edge to them,not close to piercing at all but for some it may be fatiguing for long sessions.Example there is great synergy with the N6/mojo but in sharp roll off and on bright recordings like some chillout,the rich overtones in guitar strings/violins,can be borderline for some sensitive to treble.

Ie something like this https://itunes.apple.com/us/album/chillout-winter-2018/1314441154 ,song 11,33 etc

 

[dcguy73]

Can you identify the frequency of the said preak? It shouldn't be more peaky than HD650 based on graphs and om my @nd others' hearing

I wish I could help, but I returned my 660s for a refund last month, so I can't do any more critical listening with them.

 

[Laurence11]

My experience of open headphones is fairly much zero but these sound excellent using my Mojo/Poly.
The treble seems just right to me, no spikes or harshness.

Hi there

Totally agree! That’s my combo (with stock cable) and it’s simply heaven.

High res from Glider.

Loving the 660’s! And the mojo/poly!

 

[psikey]

The HD660S also sounds great out of a ZX300 balanced. I'm enjoying more than with Mojo. Perfect through the range but with wider sound stage/placement. The Mojo can drive them much louder though.

 

[Caruryn]

The thing is that with mojo it is not that clear-cut,really depends the source you connect it with.Sounds better with a dap than with a phone and the better the dap the better the sound that comes out of mojo and hp.

 

[Sigmaaa]

Can anyone then identify the frequency of the "peakines"? There were a few who noticed it. I'm wondering if it's more like a high-midrange treble thing, like hd600, 3.5kHz, although graphs don't show anything there. Or maybe is the slight 5kHz peak that graphs show, but that's lower than hd650. It can be the more dynamic and vivid character that's bothering, but hey, the hd650 were bashed continuously for sounding dead, lifeless, flat, veiled. Add just a tiny bit of dynamic and openness and voila, now they're peaky, harsh, edgy, aggressive. I wasn't bothered by the hd650 smooth character and I am not bothered by the hd660s livelier character, they're both ok for me.

 

[kman1211]

Can anyone then identify the frequency of the "peakines"? There were a few who noticed it. I'm wondering if it's more like a high-midrange treble thing, like hd600, 3.5kHz, although graphs don't show anything there. Or maybe is the slight 5kHz peak that graphs show, but that's lower than hd650. It can be the more dynamic and vivid character that's bothering, but hey, the hd650 were bashed continuously for sounding dead, lifeless, flat, veiled. Add just a tiny bit of dynamic and openness and voila, now they're peaky, harsh, edgy, aggressive. I wasn't bothered by the hd650 smooth character and I am not bothered by the hd660s livelier character, they're both ok for me.

It’s honestly probably the slightly forward upper midrange causing the issue as the HD 660 S can have a bit of a hard and slightly dry characteristic to it reminiscent of the HD 600 and DT 1990, it’s the only part of the HD 660 S tuning I can see bothering someone. The Amiron is more relaxed in this region, the Amiron can have occasional sharpness in the upper treble whereas the HD 660 S can have occasional hardness in the upper midrange.

 

[kiromn]

Guys please keep in mind that without burning in (at least 100 hours) my HD660s also gave me some strange ear resonances in the midrange. Now they sound incredible to me with vali2 and philips SQ tube.

 

[DavidA]

Can anyone then identify the frequency of the "peakines"? There were a few who noticed it. I'm wondering if it's more like a high-midrange treble thing, like hd600, 3.5kHz, although graphs don't show anything there. Or maybe is the slight 5kHz peak that graphs show, but that's lower than hd650. It can be the more dynamic and vivid character that's bothering, but hey, the hd650 were bashed continuously for sounding dead, lifeless, flat, veiled. Add just a tiny bit of dynamic and openness and voila, now they're peaky, harsh, edgy, aggressive. I wasn't bothered by the hd650 smooth character and I am not bothered by the hd660s livelier character, they're both ok for me.

It’s honestly probably the slightly forward upper midrange causing the issue as the HD 660 S can have a bit of a hard and slightly dry characteristic to it reminiscent of the HD 600 and DT 1990, it’s the only part of the HD 660 S tuning I can see bothering someone. The Amiron is more relaxed in this region, the Amiron can have occasional sharpness in the upper treble whereas the HD 660 S can have occasional hardness in the upper midrange.

The HD600 did bother me at times and with the help of others figured it was in the 3.5-5khz range that was the issue for me with some tracks. While the HD660S is fairly close to the HD600 the issue of the 3.5-5khz peak never bothered me on the HD660S but it is a sharper sound in the upper mids/lower treble than the HD650 with some gear that I can see being an issue for some.

I've never considered the HD650 veiled, lifeless or flat but its probably due to the choice of amp (BH Crack + tubes) for me.

@kiromn, the HD660S that I heard had about 200+ hours on them and per the owner and his two daughters they didn't change with burn-in. There was no noticeable "burn-in" with any of my headphones except for my EL-8 open which the changes were so drastic it was hard/impossible not to notice the overall change from dark/warm > warm/neutral (+50hrs) > neutral (+200hrs) and to this day is still one of my favorites.

 

[Mike F]

It's possibly not widely known here that the HD650 has for many years been considered a serious tool for critical listening, editing, and even mixing by sound engineers. In fact I would say that the HD650 is generally preferred over the HD600 (which is usually regarded as more neutral here) because the HD650 is more resolving of fine detail and has a slightly better sound stage. It also has less distortion of course. I personally think that it is also tonally the more accurate of the two (more natural) even though it's less neutral.

I presume that Sonarworks needs no introduction here, but check them out if you're not familiar with them and what they do. Here is a review from them of the HD660S https://sonarworks.com/blog/studio-headphone-review-sennheiser-hd660-s/

Here are a few highlights:-

'This probably is what everyone is dying to see. The graph shows that the HD660 S basically mirrors the older HD650 up until 6kHz and then starts doing its own thing. This really isn’t AKG or Beyerdynamic grade brightness, but for critical listening it’s a no go. Voice, string and other overtones will get unnatural emphasis. Sweeps will also be hard to get super precise.'

'The HD660 S is an attempt to evolve the HD650 into something more exciting. The problem is that much of what made the HD650 great for sound editing has been therefore lost. It’s still a decent headphone for recreational listening, because of extra sparkle up top.'

I'm sure that Sennheiser will make plenty of sales with the HD660S, but personally I'm staying with the HD650's (I also have the HD800). In fact, just in case Sennheiser really do discontinue the HD650 in favour of the HD660S, I've ordered another pair!

 

[amartignano]

It's possibly not widely known here that the HD650 has for many years been considered a serious tool for critical listening, editing, and even mixing by sound engineers. In fact I would say that the HD650 is generally preferred over the HD600 (which is usually regarded as more neutral here) because the HD650 is more resolving of fine detail and has a slightly better sound stage. It also has less distortion of course. I personally think that it is also tonally the more accurate of the two (more natural) even though it's less neutral.

I presume that Sonarworks needs no introduction here, but check them out if you're not familiar with them and what they do. Here is a review from them of the HD660S https://sonarworks.com/blog/studio-headphone-review-sennheiser-hd660-s/

Here are a few highlights:-

'This probably is what everyone is dying to see. The graph shows that the HD660 S basically mirrors the older HD650 up until 6kHz and then starts doing its own thing. This really isn’t AKG or Beyerdynamic grade brightness, but for critical listening it’s a no go. Voice, string and other overtones will get unnatural emphasis. Sweeps will also be hard to get super precise.'

'The HD660 S is an attempt to evolve the HD650 into something more exciting. The problem is that much of what made the HD650 great for sound editing has been therefore lost. It’s still a decent headphone for recreational listening, because of extra sparkle up top.'

I'm sure that Sennheiser will make plenty of sales with the HD660S, but personally I'm staying with the HD650's (I also have the HD800). In fact, just in case Sennheiser really do discontinue the HD650 in favour of the HD660S, I've ordered another pair!

Those Sonarworks site sound evaluations based almost only on measurements (!!my God still there they are...!!) are completely questionable. Indeed, Hd660S has somewhat slightly subdued voice and string overtones (aka a slightly subdue mid-high frequency region), the exact opposite of what they try to imply from their (very strange)* measurements. Moreover, the critical listening / mixing is more a fact of properly knowing your headphone behavior (above a decent quality level obviously), than the use of a particular headphone. I know renowned people that uses Beyer T1 and produces worldwide appreciated recordings.


*For example, Innerfidelity measurements show the Hd660S to have a smoother behavior in the mid to high frequency range, compared to the 650.

 

[Mike F]

Well, as you mention Innerfidelty, here's what Tyll had to say about SW recently.

https://www.innerfidelity.com/conte...orks-headphone-correction-equalizing-software

Here's an excerpt:-

'No surprise, with numerous successful studio tweaks under their belt, recording professionals started asking if they could do similar things for studio headphones. They started looking into it...no surprise, they found out it was a lot harder than they expected. When I told them I felt EQing headphones was at least four times harder than EQing speakers they both nodded their heads in agreement. None the less, they persisted.

Though they wouldn't go into detail, they've found a way to transfer their understanding of neutral on speakers to headphones. They do have at least four measurement systems to acquire data for over-ear, on-ear, in-ear, and intra-conchal (ear-bud) headphones. They've taken may thousands of headphone measurements, and currently have compensation curves for 117 headphones.'

Be assured, they know how to measure headphones!

But yes, you're right, mixing on headphones is more about knowing your phones than about which phone you're using. Nonetheless pros want to use something which is as 'correct' and therefore helpful as possible. I think the reference to 'Beyer bright' was more a reference to the likes of the DT880 rather than the T1.

 

[amartignano]

Well, as you mention Innerfidelty, here's what Tyll had to say about SW recently.

https://www.innerfidelity.com/conte...orks-headphone-correction-equalizing-software

Here's an excerpt:-

'No surprise, with numerous successful studio tweaks under their belt, recording professionals started asking if they could do similar things for studio headphones. They started looking into it...no surprise, they found out it was a lot harder than they expected. When I told them I felt EQing headphones was at least four times harder than EQing speakers they both nodded their heads in agreement. None the less, they persisted.

Though they wouldn't go into detail, they've found a way to transfer their understanding of neutral on speakers to headphones. They do have at least four measurement systems to acquire data for over-ear, on-ear, in-ear, and intra-conchal (ear-bud) headphones. They've taken may thousands of headphone measurements, and currently have compensation curves for 117 headphones.'

Be assured, they know how to measure headphones!

But yes, you're right, mixing on headphones is more about knowing your phones than about which phone you're using. Nonetheless pros want to use something which is as 'correct' and therefore helpful as possible. I think the reference to 'Beyer bright' was more a reference to the likes of the DT880 rather than the T1.

Ok, but they imply from the measurements something about the sound of the 660S that is almost the opposite at listening.
And measurements in the high frequencies with headphones is still a tricky thing, that not even mighty sonarworks people has completely solved (see the differences I stressed before)
Not mentioning that to imply sound impressions only from the frequency response is completely silly. There are more players in the game, even only looking at measurements.

I know they do good work with their products, I'm only saying that these review has to be taken with a grain of salt.