[pietcux]

I am just getting started. The HD660S2's sound great from Lotoo Paw Gold Touch. The Sony NW-WM1Z is far too under powered to make them sing. So far, with LPGT, positive impressions initially.

I run them like all my headphones from the Sony NW-WM1A. I cannot call the DAP underpowered. High gain 78% volume. But depending on the condition your ears are in ymmv.

 

[Rob80b]

How many hours of music playback did you put on before you really noticed your headphones to sound fully open and at its max potential? Just curious. One review said 40 hours.

With Senns fresh out of the box I've always found the biggest change was in the first couple of hours, like putting on a new pair of shoes. I crank them up and place them in a drawer or under cushions.

I do have both the Sennheiser HD700 and HD800S, and mine took about 50 before opening up.

My HD700s, like the 660S had the biggest change, wrote both off initially but after a few days they mellowed out considerably, if one could ever call the 700s mellow, lol but they were eventually my daily cans until my HD800S and with their larger drivers, if I remember, took no time at all to settle in.

 

[Quadfather]

I run them like all my headphones from the Sony NW-WM1A. I cannot call the DAP underpowered. High gain 78% volume. But depending on the condition your ears are in ymmv.

It sounds good on my Sony NW-WM1A, but LPGT kicks the quality up with the extra power

 

[pietcux]

It sounds good on my Sony NW-WM1A, but LPGT kicks the quality up with the extra power

First you wrote sounds like garbage.. I am ok with sounds good.

 

[Quadfather]

First you wrote sounds like garbage.. I am ok with sounds good.

I always try to maximize sound. I am a bit picky. I wrote that after using LPGT. It sounds good...but, compared to LPGT...

I REALLY like SRH1540 headphones from the Sonys.

Everyone's ears are different. I was really blown away with HD660S2 after plugging in to LPGT. Sorry to be confusing. I am glad that you're enjoying your Senns. I have had people tell me HD660S2 sounds like crap out of LPGT compared to a desktop. To me it is wonderful. I think HD660S2 probably scales up nicely.

 

[sygnus21]

My HD700s, like the 660S had the biggest change, wrote both off initially but after a few days they mellowed out considerably, if one could ever call the 700s mellow, lol but they were eventually my daily cans until my HD800S and with their larger drivers, if I remember, took no time at all to settle in.

I have the same reaction when I first got my HD700 phone; they sounded so bad, I thought they were defective and was going to send them back, but after asking questions in the HD700 forums, users got me straight, and sure enough after about a week, things got better.

I will also say, your amp has a lot to do with it also. If your amp is weak.... or too bright sounding as my Teac UD-503 DAC / headphone amp bright, you'll be taken aback how the Sennheiser HD700/800/800S will initially sound, and especially if this is your first foray into open back headphones as it was for me.

Give them time to settle and you will be happy

 

[WailingBanshee]

With Senns fresh out of the box I've always found the biggest change was in the first couple of hours, like putting on a new pair of shoes. I crank them up and place them in a drawer or under cushions.

My HD700s, like the 660S had the biggest change, wrote both off initially but after a few days they mellowed out considerably, if one could ever call the 700s mellow, lol but they were eventually my daily cans until my HD800S and with their larger drivers, if I remember, took no time at all to settle in.

Agreed. For me the first week of using them, the mids sounded a bit muddy. It eventually mellowed out and became much more balanced. I had to compensate with EQ at first and but one day I turned it off and was surprised at how quickly my impressions changed.

Also worth noting that these headphones work best with a neutral but well extended source. Too much warmth from lets say your amp could make the mids muddy. I've been experimenting with different tube combinations on my amp and have had the most success with more neutral tubes.

 

[nuxos]

After a couple of months enjoying the HD660S2 with the Fiio K9 Pro (ESS), it was time to deliver my humble feedback to the thread

Introduction

To begin, I had a HD650 around 2016 and sold it with many regrets after maybe a year. Later on in 2020 was the Philips Fidelio X2HR which was just incredible for the price point (100€) driven by a Fiio K5 Pro (AKM). I had tried again the HD650 in 2022 but the bass was not so much to my liking anymore and returned it to the seller. Then came a home period since January 2024 for which I had time and money to spend on a totally new setup. I discovered the HD660S2 and it seemed to really meet my expectations.
The source I was the most interested was the K9 Pro (ESS). Alternative choices were the Asgard V3 multibit DAC and the DX7Pro Plus. Went for the Fiio and bought a XLR cable for the occasion. The idea was to get a very neutral source, all in one solution to avoid trying too many different DAC and Amps.

My thoughts

Until now, I have listened to a good variety of styles on QOBUZ - jazz - rock - classical - reggae - country - blues - electronic - and the 660S2 is clearly versatile. The signature is globally on the slightly warm side, still very natural. Treble is not so softened nor too present : for me it's the right balance. And for the bass, while it's not the most basshead headphone you will find, the impact can be visceral if needed.

And of course, I find back what I loved the most on the HD650 : those magical vocals and guitar/piano notes! I also feel more width, separation and overall technique to be on top. Of course, the K9 Pro helps to bring the best technical presentation possible. Compared to the K5 Pro, the power is of course more important, but the technical difference really shines on the well (re)mastered albums. It remains rather forgiving with poor recordings. On the sound ability, it is superior to the HD650 without a doubt.

Comfort wise, I have a bit smaller than average head and a thin face, hence what I like the HD6XX series for being so lightweight and kind of low profile. At first with the HD660S2, the clamp was lower than on my two previous HD650 which is a good thing. The low weight also allows for extended period without too much discomfort.

Conclusion

The HD660S2 paired with the K9 Pro (Ess) is a well balanced headphone, entertaining yet very detailed, and not fatiguing. Great comfort once the clamp is lowered a bit over time. Listening to well mastered albums is always a pleasure, while it can forgive quite well poor recordings. The best evolution I could hope for the HD650!

 

[csch92]

After a couple of months enjoying the HD660S2 with the Fiio K9 Pro (ESS), it was time to deliver my humble feedback to the thread

Introduction

To begin, I had a HD650 around 2016 and sold it with many regrets after maybe a year. Later on in 2020 was the Philips Fidelio X2HR which was just incredible for the price point (100€) driven by a Fiio K5 Pro (AKM). I had tried again the HD650 in 2022 but the bass was not so much to my liking anymore and returned it to the seller. Then came a home period since January 2024 for which I had time and money to spend on a totally new setup. I discovered the HD660S2 and it seemed to really meet my expectations.
The source I was the most interested was the K9 Pro (ESS). Alternative choices were the Asgard V3 multibit DAC and the DX7Pro Plus. Went for the Fiio and bought a XLR cable for the occasion. The idea was to get a very neutral source, all in one solution to avoid trying too many different DAC and Amps.

My thoughts

Until now, I have listened to a good variety of styles on QOBUZ - jazz - rock - classical - reggae - country - blues - electronic - and the 660S2 is clearly versatile. The signature is globally on the slightly warm side, still very natural. Treble is not so softened nor too present : for me it's the right balance. And for the bass, while it's not the most basshead headphone you will find, the impact can be visceral if needed.

And of course, I find back what I loved the most on the HD650 : those magical vocals and guitar/piano notes! I also feel more width, separation and overall technique to be on top. Of course, the K9 Pro helps to bring the best technical presentation possible. Compared to the K5 Pro, the power is of course more important, but the technical difference really shines on the well (re)mastered albums. It remains rather forgiving with poor recordings. On the sound ability, it is superior to the HD650 without a doubt.

Comfort wise, I have a bit smaller than average head and a thin face, hence what I like the HD6XX series for being so lightweight and kind of low profile. At first with the HD660S2, the clamp was lower than on my two previous HD650 which is a good thing. The low weight also allows for extended period without too much discomfort.

Conclusion

The HD660S2 paired with the K9 Pro (Ess) is a well balanced headphone, entertaining yet very detailed, and not fatiguing. Great comfort once the clamp is lowered a bit over time. Listening to well mastered albums is always a pleasure, while it can forgive quite well poor recordings. The best evolution I could hope for the HD650!

still wondering how the k9 might be
the s2 is really amazing on my k7 pro. it sounds natural and very crisp and get very loud without any distortion. i don't think i would need an upgrade

 

[sygnus21]

if one could ever call the 700s mellow, lol but they were eventually my daily cans until my HD800S

Yeah, I kept mine going for 8 years before replacing them this year with the HD800S. I'm keeping the HD700, but they're relegated to the second team

 

[nuxos]

still wondering how the k9 might be
the s2 is really amazing on my k7 pro. it sounds natural and very crisp and get very loud without any distortion. i don't think i would need an upgrade

Power wise, the K5 Pro was already a beast and enough for the S2. The K9 amp is even more powerful and would allow to drive crazy demanding heapdhones if needed especially when balanced. The DAC retrieves a lot of details and gives a better separation, sense of layers compared to the K5 Pro. Not a night and day difference but I wanted the most of the S2 and I got it.

Last but not least : the K9 Pro gets warm quite a bit and I use it sometimes as a hand heating haha

 

[csch92]

anyone here with a pair of focal clears? how would you compare them? these catched my eyes after i bought the 109 but to be honest they where not that much of an upgrade to me, they where maybe a tend brighter while they keept a nice bass response but i demoed them and it wasn't a home experience so it should not count

 

[Bassheadd]

I’m glad the earcups are noticeably larger on the 660s2. I gave the 650 a try last December in the store and didn’t like the small earcups. Was worried the 660s2 would have the same size cups but they’re much larger.

 

[Shane D]

Had a good time today with the S2's and my Schiit Valhalla 2. First time I had these on since January and I really have missed them.

 

[kman1211]

Been spending a lot of time with the HD 660S2 lately, really starting to like and appreciate them more. Took a bit to get them just right on my system but now I am satisfied fully with them.