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Sennheiser HD650 Review (Headphone)

Robbo99999

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Hi folks,
I would like to buy a new open headphone.
I currently own a Sennheiser HD25 that I use daily, and I'm planning to had a new headphone for the living room.
I already own a RME ADI-2, are there any others valid options in Europe in the price range of the HD650?
I'd recommend the AKG K702, I like it better than my HD600 which is very similar to the HD650 you mention. K702 has better soundstage, and better bass reproduction than the HD600, whilst being on par (or maybe just only slightly behind) with the HD600 in other areas like midrange....but only get the K702 if you're gonna be EQ'ing your headphone, as a bonus in Europe the K702 is very cheap in comparison. If you're not gonna EQ your headphone then get the HD600 as it's so close to the Harman Curve without EQ, but only get the HD600 & HD650 if soundstage is not particularly important to you, as they have the worst soundstage (very closed in on your head) than any of the other headphones I have in my signature.

EDIT: I have an EQ for the K702 which I did that is based on a measurement of the K702 by Crinacle, I'm pretty happy with the result, but I'm sending my K702 to Oratory for measurement of old vs new pads too, so Oratory would be creating an EQ profile for the K702 in the coming months if all goes to plan.
 
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solderdude

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I would like to buy a new open headphone.
I currently own a Sennheiser HD25 that I use daily, and I'm planning to had a new headphone for the living room.

What kind of music do you listen to ?
Do you prefer the sound of the HD25 (which version ?)
Do you plan to use EQ ?
 
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amirm

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I did try Amir's filters (minimum phase, constant Q, 16384 taps), and it sounds pretty good. I was afraid the bass would be overwhelming (knowing what a bass head Amir is), but it's not at all.
I actually am quite sensitive to mid to upper bass bloat. The EQs that I apply bring up sub-bass which normally are not even audible. This not only fixes that flaw but also balances the highs. Our hearing is so insensitive to deep bass there is little danger of overdoing it there.
 

ishouldbeking

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Actually.....yours is from Feb 2019, the one I have is from October 2019.


Seems like he changed the bass correction to get rid of that distorted flab which some of the HD650 EQ's have.

Unless I'm misreading something, the one I shared is the parametric EQ from February 2019 (v2.8).

The ones you just shared as attachments are (1) the same exact parametric EQ profile from February 2019 (v2.8), (2) the 6-band EQ from February 2019 (v2.8), and (3) a 10-band graphic EQ (not parametric) profile from October 2019 (v2.9). The bass setting would be different (in this case less precise) because you can't target specific frequencies or adjust the Q-factor like you can with a parametric EQ. I just checked his index again, and I don't see a newer parametric profile.

EDIT: hope that didn't come off argumentative; just trying to clarify. Let me know if there is a newer one, as I'd love to see it if so!
 

Docteur Poulet

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Hi,

Thank you for the answers, and please pardon my broken english because of omelette du fromage!
I listen all kind of music, mostly electronical music. Also jazz, sometime classical, instrumental music...
Of course I'm open to EQing the headphone, this is the reason why I bought the RME DAC.

I really like my HD25 but tend to be uncomfortable for long listening periods.
Confort and "balanced sound" is my goal. By balanced sound, I mean neutral sound.
One another reason I enjoy the HD25 is the profusion of spare parts. It is easy to repair it. The HD650 seems to be like this too.
 

Robbo99999

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Hi,

Thank you for the answers, and please pardon my broken english because of omelette du fromage!
I listen all kind of music, mostly electronical music. Also jazz, sometime classical, instrumental music...
Of course I'm open to EQing the headphone, this is the reason why I bought the RME DAC.

I really like my HD25 but tend to be uncomfortable for long listening periods.
Confort and "balanced sound" is my goal. By balanced sound, I mean neutral sound.
One another reason I enjoy the HD25 is the profusion of spare parts. It is easy to repair it. The HD650 seems to be like this too.
K702 is very comfortable too. They're OK for electronic music with deep bass, but not the best headphone on the planet for that. I also have the HiFiMan HE4XX, which is a planar headphone and that does superb bass after EQ, and it's got a good soundstage, 2nd place to my K702 on soundstage out of my 4 different headphones, it praps doesn't resolve detail quite as well as the K702, but it's got beautiful bass. For you to get a feeling on how much bass these headphones can deliver after EQ, have a look at my EQ I did to fit the Harman Curve of both the K702 & the HE4XX that I'm recommending you, and note that these are optimum levels of bass for the headphone, particularly the K702 where I felt there were negative effects by giving it more bass than what you see here (in terms of boosting it too much removes bass definition and also takes clarity away from the rest of the headphone), so this is the optimum:
AKG K702:
Crinicle K702 best measurement EQ (clear bass).jpg
Hifiman HE4XX:

HE4XX second attempt.jpg
So this gives you a feel for the bass capabilities of these headphones once EQ'd, and also how close they are to the Harman Target when stock.
 

solderdude

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Hi,

Thank you for the answers, and please pardon my broken english because of omelette du fromage!
I listen all kind of music, mostly electronical music. Also jazz, sometime classical, instrumental music...
Of course I'm open to EQing the headphone, this is the reason why I bought the RME DAC.

I really like my HD25 but tend to be uncomfortable for long listening periods.
Confort and "balanced sound" is my goal. By balanced sound, I mean neutral sound.
One another reason I enjoy the HD25 is the profusion of spare parts. It is easy to repair it. The HD650 seems to be like this too.

The HD650 is well supported and will still be so in the future. It will take getting used to compared to HD25, tonally.
No deep bass, smoother treble and more comfort.
I would recommend to go for HD650. EQ is not really needed but some gentle EQ does improve them. I would call the HD650 an 'honest' headphone with an intimate soundstage. Well suited for the RME.
 

ishouldbeking

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Hi,

Thank you for the answers, and please pardon my broken english because of omelette du fromage!
I listen all kind of music, mostly electronical music. Also jazz, sometime classical, instrumental music...
Of course I'm open to EQing the headphone, this is the reason why I bought the RME DAC.

I really like my HD25 but tend to be uncomfortable for long listening periods.
Confort and "balanced sound" is my goal. By balanced sound, I mean neutral sound.
One another reason I enjoy the HD25 is the profusion of spare parts. It is easy to repair it. The HD650 seems to be like this too.

I think it depends on the type of neutral sound you like. I would describe the stock tuning of the 650 (and 6xx) as warm-neutral, with rolled off sub-bass and smooth, slightly muted treble; the focus is really on the midrange. With EQ, you can add back a lot of the missing sub-bass and a fair amount of treble, and you can tune it to suit your tastes; I really enjoy Amir's EQ profile that aims for the Harman target, though I think of that tuning as more of an idealized "fun" tuning, where the bass is quite pronounced, just not overwhelming. I think some folks think of a neutral tuning as more of a lean/tight bass presentation and quite a bit more treble (like a stock Beyerdynamic DT880 or maybe a Hifiman Sundara). You could EQ the 650 to have that kind of bass pretty easily, but I'm not sure the treble would have that kind of airy sparkle that some folks look for. Soundstage is also pretty intimate compared to a lot of brighter open-backs that have a wider soundstage (in particular, something like an AKG K712).

Personally, I love the 650 for jazz, classical, and orchestral stuff (as well as all other genres like rock, metal, and electronic), but I'm also somewhat treble sensitive.
 

Coach_Kaarlo

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Unless I'm misreading something, the one I shared is the parametric EQ from February 2019 (v2.8).

The ones you just shared as attachments are (1) the same exact parametric EQ profile from February 2019 (v2.8), (2) the 6-band EQ from February 2019 (v2.8), and (3) a 10-band graphic EQ (not parametric) profile from October 2019 (v2.9). The bass setting would be different (in this case less precise) because you can't target specific frequencies or adjust the Q-factor like you can with a parametric EQ. I just checked his index again, and I don't see a newer parametric profile.

EDIT: hope that didn't come off argumentative; just trying to clarify. Let me know if there is a newer one, as I'd love to see it if so!

Apologies - you are indeed correct! PARAMETRIC EQ is not the same a graphical EQ with fixed Q factor. Little differences with the RME-ADI version makes me curious tho.
 

Lefty9

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I spend the last week at home A/B/C ing the 600,650,660s with all kinds of music. At the start I liked the 600 the best but after eq with the harman target oratory1990 preferences I think I might end up with the 650. The 660s where unlistenable without eq way too much blot for my liking but after the eq they cleared up alot. Still the 650 are the "smooth" option, homogenous but still detailed sound. So, although bringing the tonal balance of all the cans very close to the harman target, they still sounded quite different to each other. My conclusion,correct me if I am wrong, is that the frequency response tells only a part of the story. I am guessing there are other factors contributing to the sound of a headphone
 

ishouldbeking

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Does anybody know if it would be possible to get a similar EQ for the Sundara?
I think I gave a similar answer in another thread, but both Oratory and AutoEQ have Sundara profiles. Don't treat them as gospel; just use them as a starting point and tweak from there. Presumably Amir will develop his own profile whenever the inevitable Sundara review arrives.
 

ishouldbeking

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I spend the last week at home A/B/C ing the 600,650,660s with all kinds of music. At the start I liked the 600 the best but after eq with the harman target oratory1990 preferences I think I might end up with the 650. The 660s where unlistenable without eq way too much blot for my liking but after the eq they cleared up alot. Still the 650 are the "smooth" option, homogenous but still detailed sound. So, although bringing the tonal balance of all the cans very close to the harman target, they still sounded quite different to each other. My conclusion,correct me if I am wrong, is that the frequency response tells only a part of the story. I am guessing there are other factors contributing to the sound of a headphone

For sure. The physical characteristics of the driver itself are obviously important, and we've seen the difference distortion makes, both in terms of audible grossness (that's my technical term) and ability (or inability) to tailor the frequency response through EQ. But also enclosure design, damping, earpad construction, and other physical aspects of the design all impact what and how we experience sound in various ways. Frequency response is hugely important but not the only thing that matters. EDIT: I'm sure the more technical-minded folks can give an even clearer explanation.
 

infinitesymphony

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I spend the last week at home A/B/C ing the 600,650,660s with all kinds of music. At the start I liked the 600 the best but after eq with the harman target oratory1990 preferences I think I might end up with the 650. The 660s where unlistenable without eq way too much blot for my liking but after the eq they cleared up alot. Still the 650 are the "smooth" option, homogenous but still detailed sound. So, although bringing the tonal balance of all the cans very close to the harman target, they still sounded quite different to each other. My conclusion,correct me if I am wrong, is that the frequency response tells only a part of the story. I am guessing there are other factors contributing to the sound of a headphone
Interesting observations. The 660s had bass bloat for you? Most impressions I've read have had the bass sounding similar to the 650 with the main difference being less rolloff in the sensitivity range resulting in a subjectively brighter or less laid-back sound.

Here is a chart by @solderdude comparing the frequency responses of HD660s (teal) with HD650 (red):

hd660vs-hd650-nr-3.png
 

Robin L

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Interesting observations. The 660s had bass bloat for you? Most impressions I've read have had the bass sounding similar to the 650 with the main difference being less rolloff in the sensitivity range resulting in a subjectively brighter or less laid-back sound.

Here is a chart by @solderdude comparing the frequency responses of HD660s (teal) with HD650 (red):

hd660vs-hd650-nr-3.png
It appears to be the open-back Sennheiser signature sound, to a greater or lesser degree. I've got Drop 6XX, Sennheiser HD579, 599 open backed headphones. Also the closed backed Urbanite XL. The JPEG is of the fat bottomed HD 599, the HD 579 is pretty much the same in the upper bass, lower midrange. The PDF from Inner Fidelity is of the closed back fat sounding Urbanite XL. EQ does wonders to iron out this fatness, thought this means you're tied to playback gear capable of PEQ:

fr-hd599.png
 

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Lefty9

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Interesting observations. The 660s had bass bloat for you? Most impressions I've read have had the bass sounding similar to the 650 with the main difference being less rolloff in the sensitivity range resulting in a subjectively brighter or less laid-back sound.

Here is a chart by @solderdude comparing the frequency responses of HD660s (teal) with HD650 (red):

hd660vs-hd650-nr-3.png
Yes it's like the bass is covering,choking, the other frequencies, although it is a bit clearer, more textured than the 650s bass. Actually the whole frequency range except maybe the upper treble sounds more detailed to my ears than the 650 and a bit smoother than the 600. But overall as a whole it's sounds bloated. That is before eq. After the eq, that bloat lessens significantly and the sounds becomes even more detailed. I could hear everything that was happening, within the headphone limit of course, but it felt as if the frequencies, the instruments, where separated from each other. It lacked the homogeneity and the smoothness of the 650.

Edit. I think the red is the 660s
 

infinitesymphony

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It appears to be the open-back Sennheiser signature sound, to a greater or lesser degree. I've got Drop 6XX, Sennheiser HD579, 599 open backed headphones. Also the closed backed Urbanite XL. The JPEG is of the fat bottomed HD 599, the HD 579 is pretty much the same in the upper bass, lower midrange. The PDF from Inner Fidelity is of the closed back fat sounding Urbanite XL. EQ does wonders to iron out this fatness, thought this means you're tied to playback gear capable of PEQ:

View attachment 107616
I'm really curious about this perception of bass bloat, because if we look at the HD650 FR relative to Amir's target curve, it's actually lower than the target everywhere but 200 Hz, and he chose not to EQ that range. Is a broad 1.5-2.0 dB boost centered around 200 Hz enough to be considered bloat, is the THD in the bass range a factor, or does it come down to individual perception (e.g. the idea some people would consider any headphone matching the target curve to have bloated bass)?

index.php
 

Feelas

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I think it might be the THD, since on K371 there's a massive bass shelf and yet there's no real bloat. I feel my KNS-8400 are bloated, yet they have a lack of bass in impact & size, and it's kind of a veiled presentation of the range, and that feeling doesn't go away when equalized to flat bass (as in "all the bass notes the same"). It's one of the absurd pairs, which are at the same time:
- veiled & unclear at bass
- lacking the impact
- very bright.
 
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Robin L

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I'm really curious about this perception of bass bloat, because if we look at the HD650 FR relative to Amir's target curve, it's actually lower than the target everywhere but 200 Hz, and he chose not to EQ that range. Is a broad 1.5-2.0 dB boost centered around 200 Hz enough to be considered bloat, is the THD in the bass range a factor, or does it come down to individual perception (e.g. the idea some people would consider any headphone matching the target curve to have bloated bass)?

index.php
I hear that broad hill around 200 hz as fat/warm/bloat. I've got my eq set up to reduce the output in that area. I haven't attempted anyone else's eq, I'm happy with mine. I pull up the deep bass, but reduce the upper bass. Works for me with the Drop 6XX. Nothing I've done can really fix the HD 599, it sounds thick and veiled no matter what I do.
 
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