I love this thread.
I am trying to get down to a relatively straight forward conclusion that can be easily understood by the average reader.
It’s no debate that sound interpretation (perception) is subjective, it differs from person to person. Many factors play a major role in this - structure of the outer ear, middle ear, and inner ear.
This video alone does a great job at explaining that, and I believe it didn’t even take into consideration the variance of pinna and concha, let alone other parts of the ear. The way we interpret sound is subjective, as said before, it is a perception of sound, our individual perception. This means that you essentially cannot trust human ears as a reference, purely due to their vastly different nature from person to person.
I myself started a research on how to test objectively if a headphone is sounds reference-grade. My research ended with a conclusion: you cannot do that - our ears are the limitation that make it a subjective thing. If we (humans) were the ones as to how reference-grade a headphone sounded, that would be our very own and personal perception of it, making it subjective. So, I concluded that the only way to create a truly reference-grade (flat frequency response, aka. as little coloration as possible) would be with the help of measuring systems - they do not have the challenges and variations that our ears have. G.R.A.S. does have their measurement systems that have “ears”, and I think that is kind of going a step back - the ear itself is what makes things impossible to be objective (because all of our ears differ), so adding that to a technical thing (measuring system) is giving it the exact problem we are trying to avoid… that ear is probably based on an average from idk how many human ears, but regardless, the frequency response would be based on that exact ear structure… which would make tuning biased to that exact artificial ear structure.
I concluded that the most perfect measurement system would be the one that does not have this and only has the microphone(s) and the plate that the headphones can be mounted on - much like the G.R.A.S. 45CC that Ollo Audio uses. This way you are just testing the ear-pads and headphone driver on their own, it would avoid reflections or other factors from the artificial ear structure that would affect the sound.
I decided to look at it this way (from this part on I will be specifically focusing on as to my conclusion regarding truly testing and creating a reference-grade headphone):
Our ears are the ones are imperfect, they are the ones that have limitations and imperfections that make them subjective, but there is also the factor of how an individual interprets and perceives sound. The only way to overcome this would be to not trust our ears but let the technology do its job - technology in this case are measuring systems with microphones, specifically the frequency response graphs from these systems. If you tuned the headphone according to this system, then it would truly be a flat frequency response (if you manage to tune it to this frequency response), and our ears would be the filters that interpret it in different ways… but at the end of the day that frequency response really is what it shows it is. This means that the interpretation of this frequency response would differ due to the subjective nature of our ears, but it still makes the true frequency response truly (at least according to the measuring system). This is similar to the concept of an absolute truth/universality in philosophy.
This frequency response method would be technically correct, and that is the most important thing, because you (as a manufacturer) cannot create a headphone individually for every person… I couldn’t find anything closer to being objective than this very method.
My research started because I wanted to prove whether Ollo Audio’s S4X is what it claims to be - and I knew that for my review I needed a different approach than my usual one. I could not objectively test whether it is a reference-grade headphone nor whether it has a flat frequency response just by listening to music and judging its performance. To test it, I had to find a way that is objective, an approach that doesn’t depend on my ears. The only objective way was to have a measuring system that would objectively do that for me, a system that doesn’t depend on our ears, our hearing health, and multiple factors and challenges that make our hearing subjective. This was the only way to truly test how uncolored or colored it is.
This headphone model was intended to be used as a tool for making music, not for listening to music, so if I was to use music to test its reference ability - it would be completely useless.
I mentioned that our ears are like filters, and here is why. As you already know, there is a limitation to what we can hear, which means that there could be sound “data” that exists but we cannot hear it, and a measurement system would not have this limitation, which is why I believe it is the only objective way to truly create a flat frequency response headphone. But it would have to be a raw measuring system, (specifically talking about not having artificial ears on it), here is why:
This is a quote from a long thread from another forum where I had this discussion:
It is like limiting a robot to rotate its arm to a certain extend, when you can very well let it rotate its arm 360˚. This is the simplest example I could make that would make sense to the average reader, if you are limiting the microphone measuring system with a pair of artificial ears, you are going against the grain, you are presenting it an imperfection that human ears face (it doesn’t matter if G.R.A.S. took 10, 10 000, or a million ears and based their fake ear on the average one, from the video above, you can see why this is a big problem), you are going a step back by doing that.
Why am I so crazy about the so called “reference-grade” nature and flat frequency response? Because it should be the rawest and most true form of sound. So my journey was how do you create a tool (a headphone in this case) that does exactly that - let you hear the sound without much coloration? Actually, it was “How can I objectively prove that this headphone does or doesn’t do what it claims to, but do it objectively, not subjectively?”
I post this here because I want to hear others opinion regarding this. It is an extremely controversial topic and a complicated one too. What do you think, how would you prove that a headphone truly can be used as a reference, meaning that it presents the sound in its “truest” forms? Ollo Audio’s claim is that S4X is flat out of the box, how would you objectively approach this? Is there even a thing like this?
Note: If you do answer, expect a healthy debate. I am not trying to argue with anybody, I just think this is an interesting topic that definitely has a lot of arguments present.
