Hello Folks! Recently I've come to the conclusion through my own experience that unit to unit variation in headphones is a massive barrier/influencer to enjoyment of headphones. I've created this thread because I think Unit to Unit Variation is a massive thing that should be focussed upon by manufacturers / users / & reviewers if possible (stipulate x3 units to review each time if "pie in the sky"?). Really the unit to unit variation variable should be a massive decider in which headphone you choose to buy, and should also be forefront in manufacturers & reviewers minds.
We all know that measurements & Harman Target is a massively good starting point (& sometimes end point) for choosing a headphone that sounds great, and also increasingly for a means upon which to apply EQ to such published measurements (be it Oratory / Crinacle / Amir / Resolve or any other GRAS unit measurement reviewers out there). The problem & unpredictability starts though with unit to unit variation - those reviews & measurements only matter for that headphone unit measured, as it's possible that other units of the same headphone model will not measure the same and therefore your experience when you buy & listen to that headphone will certainly not be the same, and as it follows also if you EQ your headphone using those measurements then there's no guarantee you'll be hitting the Harman Target or whatever Target Curve you choose. This is not a problem if unit to unit variation is low, but is increasingly a problem in models & manufacturers that have larger unit to unit variation.
Now for some detail on my own unit to unit variation experience that has informed by conclusions, and you are forewarned this paragraph is long and really serving as a background account for why I think unit to unit variation is so important, so apologies in advance, and feel free to skip read this or ignore it as this thread is not about me but the general significance of unit to unit variation in headphones. In fact I'll put it in a Spoiler to avoid "wall of text"!
My main point being that if unit to unit variation is high then published EQ's/measurements are less reliable and the harder it is to arrive at a good sound if the starting point is so far off. (I haven't provided frequency response graphs showing unit to unit variation I've mentioned as I'm making a general point and this thread is not about me, but I can include them in later posts if asked).
As an additional point of interest/discussion, going back to the title of the thread, what causes this unit to unit variation on a technical level? Is it just the manufacturing tolerances of the driver itself, as in the "plastic capsule" of a dynamic headphone or the "stretched metal paper" of a planar headphone itself that creates the unit to unit variation.....or is it also everything else within the headphones construction including pad unit to unit variation & perhaps variation in how that has been installed, and perhaps variation in the things like foam insert discs and how accurately they have been placed.....maybe headphone band tension variability & all other manner of physical construction tolerances/variables??? So this paragraph is about asking what really causes unit to unit variation? And an additional thought how do manufacturers control these variables? Do we know for sure which manufacturers have the best (lowest) unit to unit variation, do we know which models have the best unit to unit variation....would be great if there was a resource for this that could show us the answers to this question? Hell, manufacturers should strive towards that goal (& publish the variance especially if they want to market their headphone to well-informed buyers?)?
So really this thread is anything related to unit to unit variation, as I think it's a super important topic in order to get a best headphone experience. Let the discussions commence, in my experience it's a very important topic that can be a make or break for enjoyment of a headphone, and one that is often overlooked by both reviewers / measurers & users alike! Looking forward to hearing from anyone with experiences / ideas / thoughts / information / answers.
We all know that measurements & Harman Target is a massively good starting point (& sometimes end point) for choosing a headphone that sounds great, and also increasingly for a means upon which to apply EQ to such published measurements (be it Oratory / Crinacle / Amir / Resolve or any other GRAS unit measurement reviewers out there). The problem & unpredictability starts though with unit to unit variation - those reviews & measurements only matter for that headphone unit measured, as it's possible that other units of the same headphone model will not measure the same and therefore your experience when you buy & listen to that headphone will certainly not be the same, and as it follows also if you EQ your headphone using those measurements then there's no guarantee you'll be hitting the Harman Target or whatever Target Curve you choose. This is not a problem if unit to unit variation is low, but is increasingly a problem in models & manufacturers that have larger unit to unit variation.
Now for some detail on my own unit to unit variation experience that has informed by conclusions, and you are forewarned this paragraph is long and really serving as a background account for why I think unit to unit variation is so important, so apologies in advance, and feel free to skip read this or ignore it as this thread is not about me but the general significance of unit to unit variation in headphones. In fact I'll put it in a Spoiler to avoid "wall of text"!
I mentioned earlier of "my own experience", well I've got 3 units of K702 and 2 units of HD560s, and they do not sound the same within the same headphone model! I sent two units of K702 to Oratory to measure and one unit of HD560s - he also kindly sent me the personalised measurements of those headphone units to me so I could do EQ's to the Harman Curve based on those measurements - thereby defeating any unit to unit variation when EQ'ing to the Harman Curve - turns out I like the Harman Curve! However, a third K702 I bought that has not been measured by Oratory and I tried applying the published Oratory EQ to that and it was an improvement, but due to my experience I knew there was more tweaking to be done.....using his broad customisation filters that are designed to be tweaked by the user I was able to bring again closer to what I experience as accurate/ideal, but still I could not quite reach what I know to be the best target. The reason for this failure is due to the large unit to unit variation of the K702. I say this because that's been "proven" by Oratory's measurements of the two headphones I sent him, but also I have a contrasting successful experience with the HD560s where I was able to tweak my second unmeasured unit of HD560s to sound really the best experience I've had in a headphone, even better than the unit of HD560s I sent to Oratory that was personally measured by him after doing an EQ based on that individual unit's measurement. I think the reason for my success of tweaking my second unit of HD560s was that the HD560s does not have a high degree of unit to unit variation so the Oratory EQ was really a great starting point upon which his "user customisation filters" were able to allow me to tweak them to what is for me a perfect (best so far in headphones) & accurate sound.
As an additional point of interest/discussion, going back to the title of the thread, what causes this unit to unit variation on a technical level? Is it just the manufacturing tolerances of the driver itself, as in the "plastic capsule" of a dynamic headphone or the "stretched metal paper" of a planar headphone itself that creates the unit to unit variation.....or is it also everything else within the headphones construction including pad unit to unit variation & perhaps variation in how that has been installed, and perhaps variation in the things like foam insert discs and how accurately they have been placed.....maybe headphone band tension variability & all other manner of physical construction tolerances/variables??? So this paragraph is about asking what really causes unit to unit variation? And an additional thought how do manufacturers control these variables? Do we know for sure which manufacturers have the best (lowest) unit to unit variation, do we know which models have the best unit to unit variation....would be great if there was a resource for this that could show us the answers to this question? Hell, manufacturers should strive towards that goal (& publish the variance especially if they want to market their headphone to well-informed buyers?)?
So really this thread is anything related to unit to unit variation, as I think it's a super important topic in order to get a best headphone experience. Let the discussions commence, in my experience it's a very important topic that can be a make or break for enjoyment of a headphone, and one that is often overlooked by both reviewers / measurers & users alike! Looking forward to hearing from anyone with experiences / ideas / thoughts / information / answers.
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