Sean Olive's research and the measurement rig he uses is the current state of the art. There are no other rigs or measurements or studies published that shows improved preference by people. Maybe something better will come along in the future, but as of today, this is the reference standard.
If that is considered the reference then one can call it a reference. Just as 1V is 1V etc.
Thus,
@solderdude's claim that different rigs are just as valid or that different rigs are "all good starting points" is false. No offense.
Where did I make this claim ? What I mentioned was that there are many different rigs that all are used to measure headphones that, for technical reasons, all measure differently above 1kHz for obvious reasons.
It is perfectly fine to call a certain transfer function a standard. That's perfectly fine to do so and use it. When one refers to that standard one can see where it deviates. Perfectly reasonable that a very expensive and characterized measurement rig built to strict specs always performs the same way.
I do not disagree with any of this.
This situation is similar to using calibrated vs uncalibrated mics for speaker measurements. Trying to EQ with uncalibrated mic is not any different from randomly fiddling with EQ. Yeah, it sounds "better", but did you fix anything or did you make it worse?
The question is whether or not you fixed anything or made it worse when EQíng exactly acc. to a measurement made with the rig.
Don't get me wrong, I like Sonarworks, Rtings, Oratory and all the others that post 'measurements' and EQ exactly on it.
What I am questioning is whether or not the EXACT same averaged 'target curve' or 'corrections' will apply to different headphones.
Are you 100% sure that because a rig is expensive and complies to a certain standard one can EQ on it (exactly) and get trustworthy results ?
Toole's spinorama and Olive's GRAS measurements are state of the art measurements. Amir's measurements on these forums are the same. As a consumer, I want accurate specs to compare products, no more, no less. All this fuzzy "yeah, but" without good measurements or good data to me are same as fawning over vinyl and tube.
Fully agreed, and certainly in the electrical plane absolutely correct.
Also I am not claiming to have more experience nor knowledge than the mentioned guys or other notable figures in this business at all.
What I am saying is that a 'standard' correction curve is just that, an averaged curve so one can compare results under calibrated circumstances.
That does not mean that correction curve exactly compensates perfectly for all headphones.
There will (with 100% certainty in my mind) be substantial errors with different headphones compared to the actual compensation and measured signal.
If one EQ's on those errors opposite the standard then that is just as bad as using an uncalibrated microphone or doodling about with EQ.
It also is not accurate.
But surely... one can be 100% sure the headphones HAVE been measured to a standard with a high precision.
Can you tell me with
absolute certainty that all headphones are measured exactly as to how they sound with
one single averaged correction curve under all conditions then and that this is so accurate you can EQ small variations on it ?