[Xerosnake90]

I grabbed a pair of the 660s off another head fi user about a week ago. I've always been a soundstage lover. The 1990s are spacious and the Arya even more so. I like my 1990s for use on my keyboard and don't use it much to listen anymore. The Arya V2, while mystical are heavy, uncomfortable and the sibilance is bothersome.

I always avoided the 600 series cuz of their intimate presentation but people just kept talking about them so I had to give them a try. I prefer them quite a bit over the Amiron Home that I had. There's not an ounce of sibilance, and it's almost never hot. Even my treble friendly pop songs are smooth and comfy. It took me a couple of days to get used to the presentation and their sound.

The mids are warm and beautiful in a way that never muddies up the mix or interferes with the upper frequencies. I like how smooth they are up top, and they're versatile. While they're not as bass heavy as the 1900s or Arya V2 they have just enough to keep things fun.

This is the best I've heard mids sound, and with that the best I've heard vocals. I'm hearing vocal nuances I've never noticed. The imaging is also very good, the wall of sound I was worried about isn't really there. Songs are layered, separated and the sound is surprisingly large and full. Even without my beloved Soundstage, I feel immersed in the music.

While I don't touch EQ with my 1990s and Arya I'm finding the 660s sound even better with Oratory's EQ profile.

They've definitely given me a huge appreciation for a more mid centric sound and I don't even mind that they're not as open as my other cans are

 

[kman1211]

I grabbed a pair of the 660s off another head fi user about a week ago. I've always been a soundstage lover. The 1990s are spacious and the Arya even more so. I like my 1990s for use on my keyboard and don't use it much to listen anymore. The Arya V2, while mystical are heavy, uncomfortable and the sibilance is bothersome.

I always avoided the 600 series cuz of their intimate presentation but people just kept talking about them so I had to give them a try. I prefer them quite a bit over the Amiron Home that I had. There's not an ounce of sibilance, and it's almost never hot. Even my treble friendly pop songs are smooth and comfy. It took me a couple of days to get used to the presentation and their sound.

The mids are warm and beautiful in a way that never muddies up the mix or interferes with the upper frequencies. I like how smooth they are up top, and they're versatile. While they're not as bass heavy as the 1900s or Arya V2 they have just enough to keep things fun.

This is the best I've heard mids sound, and with that the best I've heard vocals. I'm hearing vocal nuances I've never noticed. The imaging is also very good, the wall of sound I was worried about isn't really there. Songs are layered, separated and the sound is surprisingly large and full. Even without my beloved Soundstage, I feel immersed in the music.

While I don't touch EQ with my 1990s and Arya I'm finding the 660s sound even better with Oratory's EQ profile.

They've definitely given me a huge appreciation for a more mid centric sound and I don't even mind that they're not as open as my other cans are

There is a reason the HD 6xx series is quite beloved. I think every audiophile needs to at least try one of the series. The imaging on the HD 660S and HD 660S2 is very good and the imaging on the older pairs the HD 600 and HD 650 isn’t as bad as people say imho.

 

[Tripokaridos]

There is a reason the HD 6xx series is quite beloved. I think every audiophile needs to at least try one of the series. The imaging on the HD 660S and HD 660S2 is very good and the imaging on the older pairs the HD 600 and HD 650 isn’t as bad as people say imho.

Fully agree both 660 have amazing imaging, even compared to my Sundara .

 

[kman1211]

Fully agree both 660 have amazing imaging, even compared to my Sundara .

Yeah, very solid in their price range. Not quite R70x good in terms of imaging but very good and better than most in the price point range. The HD 660S/660S2 are mid-tier Beyer level in terms of imaging which is very good as Beyer’s excel at imaging.

The R70x is basically the best at imaging in its price range, don’t really hear better until I get to a Beyer T1.

The R70x is around the HD 660S in terms of fidelity and has a similar sound; it is a good alternative considering the HD 660S is now discontinued as it sounds closer to the HD 660S than the HD 660S2 does imho. The HD 660S2 is of higher fidelity but it’s a different sound signature leaning more on the warm and lush side.

Basically I view the HD 660S as a modern take on the HD 600. Whereas I find the HD 660S2 a modern take on the HD 650. Though the HD 660S doesn’t outdo the HD 600/650 in terms of fidelity whereas the HD 660S2 actually does outdo them in terms of fidelity.

 

[Angel III]

The worst flaw of the HD660S was that they play inside your head.My HD650 (2013) sound significantly further away and let me hear more musical details.
I would like to buy the HD660 S2, but I have some doubts about the soundstage.

 

[kman1211]

The worst flaw of the HD660S was that they play inside your head.My HD650 (2013) sound significantly further away and let me hear more musical details.
I would like to buy the HD660 S2, but I have some doubts about the soundstage.

Do you have an old or recent HD 660S? The newer ones after the pad refresh have by far the widest soundstage of the HD 6xx series to me. My HD 660S is a 2022/3 pair. The early ones were intimate and a bit too energetic in the upper mids to my ears. My HD 660S2 soundstage is around the same size as my HD 650 (2023) soundstage.

 

[Angel III]

Mine were from 2021. The first HD660S, if I'm not mistaken, were produced in 2017. In my opinion they were too stressful to listen to. My HD650s with the Violectric V200 and DBX1231 equalizer make me have a lot of fun.

 

[kman1211]

Mine were from 2021. The first HD660S, if I'm not mistaken, were produced in 2017. In my opinion they were too stressful to listen to. My HD650s with the Violectric V200 and DBX1231 equalizer make me have a lot of fun.

I had an early one myself, was funner to listen to but at the same time fatiguing to listen to. Newer ones are fairly flat and not that energetic. Maybe I won the lottery on mine and got one with excellent soundstaging because it's consistent across systems. But honestly been gravitating back towards Beyers more lately (T1.3, DT 900 Pro X, and DT 700 Pro X), though have always been more of a Beyer person. In terms of Senns I've mostly been using the HD 660S2 lately and occasionally use the HD 650. The HD 600 is just too fatiguing for me despite liking it more than the HD 650 and HD 660S. I'm using a G111 MKII and a Modi Multibit 2 for my system.

 

[Tripokaridos]

The worst flaw of the HD660S was that they play inside your head.My HD650 (2013) sound significantly further away and let me hear more musical details.
I would like to buy the HD660 S2, but I have some doubts about the soundstage.

That's strange my 660s have the biggest soundstage of them all 600 650 580 58x and 66s2 not by a lot but no way smaller.

 

[Tripokaridos]

Mine were from 2021. The first HD660S, if I'm not mistaken, were produced in 2017. In my opinion they were too stressful to listen to. My HD650s with the Violectric V200 and DBX1231 equalizer make me have a lot of fun.

Do u use EQ on both 650 660s when u compared them ?
Without EQ I also think that 660s are more lively.
My point of view to all HD6 line is that if u like this signature line u like all of them some more and some less ... I understand that 650 are the warmer or the 600 vocals are the best or the 660 have the best imaging and separation etch etch but I can't understand if someone like one of them , hate the others it's not possible ...
I tried many times using same song ,DAC amp and all HD 6 line side by side and there was difference's but no way big enough for anyone to say the one is masterpiece and the other crap.

 

[Angel III]

When I performed the stage test I used some audio tracks that I know well, I test with and without equalizer.

 

[Xerosnake90]

I don't get the inside my head feeling with the 660s. They're definitely the tightest out of my trio (DT 1990, 660s, Arya V2) but they still surround me and actually have a pretty impressive holographic imaging thing going on.

 

[SHAMuuu]

There is a reason the HD 6xx series is quite beloved. I think every audiophile needs to at least try one of the series. The imaging on the HD 660S and HD 660S2 is very good and the imaging on the older pairs the HD 600 and HD 650 isn’t as bad as people say imho.

You can just mash them together old and new as well

 

[kman1211]

You can just mash them together old and new as well

I noticed the HD 660S/S2 grills do change the sound some, some changes in imaging and it seems to calm the upper mids some. Though I am slowly using the HD 6xx line less and less, ended up favoring the R70x with an aftermarket cable to any of the HD 6xx line. Some reason each HD 6xx headphone has me searching for something sonically except the HD 600 but that is a little intense in the upper mids. The HD 660S2 is almost there, may simply be finding the right system for it.

 

[SHAMuuu]

I noticed the HD 660S/S2 grills do change the sound some, some changes in imaging and it seems to calm the upper mids some. Though I am slowly using the HD 6xx line less and less, ended up favoring the R70x with an aftermarket cable to any of the HD 6xx line. Some reason each HD 6xx headphone has me searching for something sonically except the HD 600 but that is a little intense in the upper mids. The HD 660S2 is almost there, may simply be finding the right system for it.

The grill swaps may play a small role. Baffle swap might also play a small role. Clamp would play a small role. And I guess old pads vs new pads etc.
But doing all of them defo results in a noticeable change.

The 660S driver sounds like a 6 series, but it also has some ... i don't even know what word to use... some sort of "edginess" . Perhaps I have used that word before, and someone else used the term "digital glare"

I tried the 660S driver with an older black paper baffle, and a headband from past which was much looser. With a buffer (itube) in system, it sort of smoothed it over.
It's not unlistenable or bad or anything like that, but it leaves me with similar feelings like ath-ad1000x after longer periods of time vs some other Sennheisers.

E.g 580 (II gen) driver with the new (660 S1/2 baffle), Custom Cans copper ring, older model pads, and the 660S chassis (more clamp, new cable), and it's smoother and less fatiguing.

I know the newer drivers might excell in the bass and treble regions vs the older stock versions (580/600/650), but where the mids sit, it might be personal preference.

There are differences in where the mids sit, the mid bass hump levels, and fatigue factors.

Again, it's all relative as I don't think the 6 series overall are fatiguing per se.

I will say, you were quite right about that r70x. It shocked me how much more natural sounding it is vs its ad1kx/2kx brothers,