Thank you for your well-considered and thorough reply to my posts here listener. We obviously look at some of this a bit differently, including some of the Harman conclusions.
Since you have occasional interactions with Dr. Olive, you might try asking him sometime if he still believes that most headphone listeners prefer a response close to the in-ear response of neutral speakers in a semi-reflective room. And if this is still one of his principal takeaways from the research he did with Harman. I’d be curious to know the answer to that. Because he has said as much in a number of interviews and talks he’s given about his work there. (Three of these talks can be found here.)
I’m also glad to hear that you’re not advocating for DF as a target. Because it often sounds like you believe that it should be when you simply refer to your target or baseline as “DF”. After reading your remarks above though, it’s a little clearer to me what you mean by some of this. A flat DF (or just “DF” in most audio circles) is not what you want to be using to judge the timbre of headphones though. Because it is simply too bright. I hope that most of us can agree on that. (Though I know of a couple people in your inner circle who still seem to think it should be the target, or who are at least open to using headphones that are close to DF.)
If you want to use DF as your starting point, then you obviously need to make some adjustments or corrections to it to bring it more into line with what most people would prefer, or would likely find more pleasing or neutral-sounding. IOW, you need to make it closer to the in-ear response of neutral speakers in a semi-reflective room. In my book, that means the DF is no longer a DF anymore. Because you’ve changed the timbre or tonal balance to match something else, namely the in-ear response of speakers in an SR room. And presumably this now becomes the new baseline, or reference point, or target, or touchstone, or whatever you want to call it, for judging the frequency response of your headphones. And (potentially) also making some EQ adjustments to correct it.
If you add a negative slope or the Harman filters to a diffuse field measurement to create your target, then the diffuse field measurement is no longer “DF” anymore. It’s DF plus (or minus) something else. And more than likely that DF+something is gonna be closer to something like the in-ear response of neutral speakers in an SR room, which is the reference point or target I’d really prefer for headphone measurements.
I also understand why alot of reviewers don’t want to hear something like that. Because doing good in-ear measurements of neutral speakers would be a costly and involved process… I get that. But it’s something I’d still like to see people try to work toward, instead of just more messing about with DF and different filters… Anyway, thanks for letting me say my piece on some of this.
I think the subject of personalization is also interesting. And maybe we can also have a more in-depth chat on that sometime too.
I’m just not convinced it’s that important for the kind of over-ears I use. And haven’t found it very effective in delivering the kind of results that I want. I can see some value in it for IEMs though. I’m afraid for many people it will be another unicorn chase though… That’s the way it felt to me anyway.