[Sinocelt]

  So the main question seems to be, is a flat frequency response even desirable or 'correct' in a headphone? The Harman target curve is not flat for example.

 
Actually, according to Tyll's first article on the subject, it is. While the Harman team searched for the most euphonic sound, not the most neutral, both happened to coincide: "flat, neutral response was preferred."
 
Neutrality here refers to the sound produced by two neutral loudspeakers in a well-treated room. This is the "flat" we're talking about, since true flatness (as a machine can perceive it) wouldn't sound flat to the human ear.
 
So the Harman curve is [supposed to be] the frequency response headphones should display to sound like two neutral loudspeakers in a well-treated room.

 

[Mike F]

   
Actually, according to Tyll's first article on the subject, it is. While the Harman team searched for the most euphonic sound, not the most neutral, both happened to coincide: "flat, neutral response was preferred."
 
Neutrality here refers to the sound produced by two neutral loudspeakers in a well-treated room. This is the "flat" we're talking about, since true flatness (as a machine can perceive it) wouldn't sound flat to the human ear.
 
So the Harman curve is [supposed to be] the frequency response headphones should display to sound like two neutral loudspeakers in a well-treated room.

Thanks for linking that article, Sinocelt. It's been a while since I read that, and it makes very interesting reading again. I appreciate that an enormous amount of research has been done in this field already and my questions, and indeed knowledge, just scratch the surface, but it's great to be able to discuss these things!
 
I totally agree with with your post, and yes, in one way the Harman curve can be considered to be 'flat' or 'neutral', or rather, that's the sound that it aims to produce. However, unless I'm wrong (quite possible!) the Sonarworks calibration profile produces a FR which is flat along the 0db line which, as you said in the above quote, won't sound 'flat' to the human ear. What am I missing here? 

 

[Sinocelt]

  What am I missing here? 

 
These two posts:
 
http://www.head-fi.org/t/702924/best-studio-headphones/435#post_11613649
http://www.head-fi.org/t/702924/best-studio-headphones/435#post_11615613
 

 

 

[Mike F]

   
Isn't that something the Harman curve is supposed to achieve (though that isn't the premise on which it was developed)?
 
http://www.innerfidelity.com/content/harman-researchers-make-important-headway-understanding-headphone-response
http://www.innerfidelity.com/content/headphone-target-response-curve-research-update

 
 

  Our goals are rather similar - my colleagues have talked with Sean Olive to confirm this. The difference currently is that we have a technology to implement this curve on every headphone out there.

You mean these two? What I don't understand is that in the SW video, the applied compensation results in a flat line along the 0db line, whereas that is not what the Harman curve is........?

 

[Sinocelt]

  You mean these two? What I don't understand is that in the SW video, the applied compensation results in a flat line along the 0db line, whereas that is not what the Harman curve is........?

 
I don't think this 0db line refers to machine-flat. I think it refers to hearing-flat. I quote: "when we do our calibration we strive to make every headphone sound like tonally flat speakers in a well treated room."

 

[Mike F]

   
I don't think this 0db line refers to machine-flat. I think it refers to hearing-flat. I quote: "when we do our calibration we strive to make every headphone sound like tonally flat speakers in a well treated room."

Well, that's what they say, and I understand that and think that it's certainly the ideal, but then what they show at 2.38 on their video presentation of the ATH-M50X is misleading:- https://www.youtube.com/watch?t=158&v=0c4E2LbrT_I
 
This shows the original FR becoming virtually flat along the 0db line with the implementation of the calibration profile, whereas the Harman curve would be a more or less straight line tilted up in the bass. I quote from Tyll's article which you linked above; 'To make a long story short, the results of the test showed a strong preference for the speaker-in-room curves with the modified curve being most preferred. (This modified speaker-in-room curve is essentially a tilted straight line with the bass end about 10dB above the treble end.)'
 
This is not 'flat' as shown in the SW video, so I'm still confused!

 

[RudeWolf]

The graph shown in the video would most accurately be called a Perceived Acoustic Power Frequency Response (PAPFR). As Sinocelt mentioned - flat in our graph isn't machine flat, it's ear-flat (for headphones). I find it to be more helpful in terms that when I hear an anomaly, it will be shown in the graph as something that makes sense in absolute terms. I don't need to keep in mind the compensation curve as it's already implemented.

 

[Darkseth]

Beyerdynamic Custom Studio might be a nice choice.
Removeable cable, Bass-slider (from light bass, over linear to bass-head), customizable, rather comfortable.
Seems like on of the best "allrounders" you could possibly buy.
 
If i would look for a closed (studio) headphone, that would be my first choice.

 

[Mike F]

  The graph shown in the video would most accurately be called a Perceived Acoustic Power Frequency Response (PAPFR). As Sinocelt mentioned - flat in our graph isn't machine flat, it's ear-flat (for headphones). I find it to be more helpful in terms that when I hear an anomaly, it will be shown in the graph as something that makes sense in absolute terms. I don't need to keep in mind the compensation curve as it's already implemented.

Thanks for the explanation! I totally understand that, and I understood that you meant that 'flat' was not actually flat, but when you show the FR of the ATH-M50X becoming virtually flat along the 0db line with the implementation of the calibration profile in the video, it's not clear that the original curve is actual (presumably?) but that the 'curve' after calibration is compensated. I wonder if it would be a good idea to make that clear in future videos to prevent anyone else getting confused?!

 

[Sinocelt]

  Beyerdynamic Custom Studio might be a nice choice.
Removeable cable, Bass-slider (from light bass, over linear to bass-head), customizable, rather comfortable.
Seems like on of the best "allrounders" you could possibly buy.
 
If i would look for a closed (studio) headphone, that would be my first choice.

 
Argh. I already have two Beyers in my opening post, where I try to keep only one option per brand. Do you have any experience with the DT 150 and 1350, to compare with the Custom Studio?

 

[ubs28]

Actually, according to Tyll's first article on the subject, it is. While the Harman team searched for the most euphonic sound, not the most neutral, both happened to coincide: "flat, neutral response was preferred."

Neutrality here refers to the sound produced by two neutral loudspeakers in a well-treated room. This is the "flat" we're talking about, since true flatness (as a machine can perceive it) wouldn't sound flat to the human ear.

So the Harman curve is [supposed to be] the frequency response headphones should display to sound like two neutral loudspeakers in a well-treated room.

Isn't the harman curve subjective? I read somewhere it was created by listening sessions.

Bass from speakers is different from headphones because you can feel bass with your body. Hence why it's possible those people in the experiment added more bass to the headphones as they perceive less bass despite the headphones have the same quantity of bass.

 

[donunus]

Can anyone here talk more about the Sony MDR 7510? Maybe its a less sibilant version of the 7520 even though its not as detailed? 

 

[Sinocelt]

Isn't the harman curve subjective? I read somewhere it was created by listening sessions.

 
http://www.innerfidelity.com/content/harman-researchers-make-important-headway-understanding-headphone-response
http://www.innerfidelity.com/content/headphone-target-response-curve-research-update
 
 

  Can anyone here talk more about the Sony MDR 7510? Maybe its a less sibilant version of the 7520 even though its not as detailed? 

 
I quickly mention my short experience with it in this post, but alas can't compare it to the 7520.

 

[Mike F]

Isn't the harman curve subjective? I read somewhere it was created by listening sessions.
 

 
'In a previous paper, "Listener Preference for Different Headphone Target Response Curves" the team subjectively tested a number of headphone target response curves and showed that listeners preferred curves designed to mimic the sound of good speakers in an acoustically well designed room. The In-Room target responses for this previous paper were basically very educated guesses about what a headphone would sound like if it mimicked speakers in a room. The paper of current interest essentially tests these curves in a series of subjective evaluation experiments to home in on the exact curve that listeners find most pleasing. 
"Listener Preferences for In-Room Loudspeaker and Headphone Target Responses'
 
So, essentially, yes, but how else would any ideal curve be arrived at?

 

[donunus]

Thanks for the feedback. Recently, I listened to a bunch of headphones over five hours.

• Sennheiser HD6 Mix. My biggest disappointment. The most comfortable of the headphones I tried, but the sound was plain weird.
• Shure SHR1540. Good stuff. Maybe the most euphonic of the headphones I tried, but not the most neutral -- the sound is warm and somewhat soft.
• NAD Viso HP50. Ugly, but sounds good! I liked it as much or better than the SHR1540, and it is more neutral. The sound is very cohesive.
• Sony MDR7510. The biggest surprise. I tried it mostly to see if the MDR7520 would fit me, but the sound was actually quite good. On par with the HP50, IMO.
• Sennheiser Momentum. Best looking, with good neutralish sound. I liked the HP50 just a bit better, sound-wise.
• Sennheiser Momentum On Ear. Very cute. Same sound signature as the Momentum, just not quite as refined.
• Audio Technica M50x. Not bad. While it isn't quite a basshead pair of headphones, it is still clear that the bass is north of neutral.
• Sennheiser HD25 Aluminum. This is a basshead pair of headphones! The sound is good, but clearly not neutral.
• Marshall Monitor. Weird sound, if not quite as much as that of the HD6 Mix. Muffled. Its sound can be changed, though, and I didn't try that.

I did see this after reading the whole entire thread hehehe... but yah so far as the detail is concerned, would you say they sound okay while being musical at the same time? hmm I guess I really need to buy one to know that since you can't do any more comparisons yourself if you don't have access to a pair at the moment.