How to approach to review and judge a studio/reference headphone? How to tell if something really is "reference-grade"?

So, I have two headphones that aim to do the same - represent sound without any coloring and boosting of specific frequencies. This is the same job that a studio monitor is supposed to do, to let the person producing the music make it without any “bias”.

Now, I could approach with the review like I do with any other headphones - write what I hear. However, this doesn’t satisfy me, and I am wondering how can I actually test how “reference” they are? How neutral, balanced, and uncolored they are?
This is something that I mainly want to do because that’s what they are being sold as - so my aim is to help one know how true that is. I want to let people know if they can trust this headphone to be reference-grade.

I do not have any equipment to get graphs or anything of that kind, so I am reaching out to the community for some advice. How can I accurately test if these headphones do what they are claiming?

For me it’s easy to listen and judge the headphones based on the usual music that I listen to, but I don’t think that I will be able to truly say if they are reference, mainly due to the fact that I wasn’t the one producing that music… so I cannot know how it was intended to sound. Writing a review is the easy part, writing a good and educative review is something different. I care about my content and I want it to be helpful for others, so any advice would be greatly appreciated.

Two methods. One involves using a collection of easily acquired electronics, see here. This approach is beyond my skill set, so I use a second approach that works fine for me, at least:

I use the Online Tone Generator but any sine sweep tool should do. With the Online Tone Generator set the volume to quiet conversation but not whisper quiet. Move the slider slowly and steadily left or right. Listen for any meaningful departures – either dips or rises. It’s that simple. However, it takes a bit of practice to learn to hear very gradual rises or falls in loudness. And also to distinguish what’s actual loudness vs the psychoacoustic softness of low frequencies and the psychoacoustic piercing-ness of high frequencies.

That said, there is a fundamental problem with your stated purpose. There literally is no such thing as a single neutral frequency response for headphones. People literally hear headphones differently from each other and the differences are not subtle. You may as well tell people that only size 46 extra-wide shoes are comfortable. I’m happy to explain the technical reasons why this is true for headphones yet not for live or loud speaker listening, but that gets into tl;dr territory very quickly.

As a reviewer you need to remind people that they literally hear differently than you do, especially at higher frequencies. I suspect this also carries over into sound stage and imaging perception to at least some degree.

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Thank you.

Of course, but that’s not what I meant. What a reference-grade headphone is meant to do is to represent sound with as little coloration as possible - where it’s me or anybody on this planet, any added coloration or alteration of sound is a fact - not something that is dependent on an individual. We all perceive sound differently, but the manufacturer is probably aiming for something when they decide to make a product, if they are making a reference-grade headphone, they probably have in mind for it to be safely used in studios.

Instead of reminding them, I just go on to carefully explain what I hear, usually with help of reference tracks and detailed minute stamps that explain the exact element I am referring to. I am not one of those people who tries to explain what they hear with descriptive words. There are too many reviews who just say “it’s bright”… how in the world am I supposed to interpret what is “bright” for you…? This is why I carefully explain where I hear “sparkle” or other sound elements. The biggest problem is people writing meaningless words (because they don’t explain a single one of them), this means that the written material is only valid to the person who wrote it, aka the writer. If you write that a headphone has “nice bass”, or it’s “fast”, you did not explain what any of those terms mean, nor where you heard those qualities. Btw when I say “you”, I am referring to people who write like that (>95% of reviewers). This is why I am trying to find an appropriate way to judge these headphones, because they are made to be relied on representing the sound “truly”. And I’m pretty sure you know that reference-grade aren’t made to sound good (audiophile headphones are), but rather to sound true and without the coloration that is present in audiophile-grade headphoes. All I’m trying to figure out is how to test how “true” do they sound.

In terms of your suggestions, I don’t know how well I will be able to use them. How will I be able to tell if there is any coloration? This is something that I would only be able to do if I “knew” (my perception) of how each of these tones and frequencies sounded like. Then I would be able to recognize if any of the tones/freq’s was boosted or decreased. Usually musicians have an instrument and can hear if there is any alteration to the sound of it, but then again… factors like microphone play a role in this coloration too. It is definitely a much more difficult task to be able to tell somebody if a reference-grade headphone is reference… like how do you do it? Coloration can easily have a very very negative impact - if you are a music producer, and you are making a song using a “reference-grade” headphone that has boosted bass, only you will hear this boosted bass coloration, thus the headphone is not reliable to be used as a reference - what will happen is that you will produce a song with less bass than it appears (because it appears that there is bass, while it’s actually just the coloration from the headphones). I hope you get what my goal and aim is.

I would greatly appreciate to hear you out on this. In both scenarios people are using their ears to listen - with speakers there are so many factors that play a major role in how they sound (room acoustics, density of walls, room arrangement, soundproofing, speaker placement, and many more), while headphones don’t suffer from any of those, they sit on everybody’s head and only things like sources can truly affect their sound. So with headphones the only thing that should be present is someones perception of sound, while with speakers not only is there also perception of sound present (perception of sound is how every person individually perceives sound), but also so many other factors that can further affect that perception (I stated some of these factors above). So I’m very interested to hear the deeper explanation as to how speakers sound the same to everybody (you didn’t say this directly, but this is what I concluded from “people literally hear headphones differently from each other”, I could’ve misunderstood you)

Perception is what depends from person to person. But if a headphone is colored, that’s something that is factual (idk if this is the correct word). Ones perception of this coloration is something that differs, but the fact that there is coloration is simply a fact. Now, I am trying to see how can I confirm if somebody can rely on this headphone(s) for representing sound the way it is meant to be represented.

Neutral is a concept that is impossible to nail down with today’s equipment. The measurement systems available do not 100% replicate the human ear. Also a slight placement change of the can on the measurement rig can wildly effect the measurement. Nor are the mics perfect. Or any of the other equipment. You can however get a ballpark. I would look at the available measurements for the headphone you care about and draw a conclusion from that. One measurement is not good enough. You need to look at various sources to get a general idea. Also search out decay measurements. A particular can may have a good looking FR but if there’s a 4ms resonance somewhere, this will be perceived as a response peak by the listener. Do research/homework on measurements. Nothing is as simple or accurate as you may think.


Sorry, but coloration is simply the result of multiple frequency responses sounding together. A headphone that is flat across the frequency range for your hearing will have no coloration.

This is largely true for flat loud speakers in the proper acoustic environment but is simply false for headphones.

Because headphones work on a different acoustic principle from loudspeakers (and live sound) our brains cannot use their exquisite mechanism that compensates for individual ear variations. So each person gets a different frequency response called the head-related transfer function (HRTF). This is not a subtle thing. Somewhere on YouTube there is a video that plays back the wildly different things different people are hearing when they listen to exactly the same source sound.

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^^^ This, I’d wager if you took the top ‘rated/talented’ studio engineers then you’d get a big difference in their personal choices and a lot to their picks would be humble compared to what we call “reference”.


Thanks for clarification. I think I get your point more now. However, wouldn’t this mean that there is no possible way to make a true reference headphone because every person would be hearing it vastly different?

I agree with everything you said. Imagine how hard it would be to make every person place the headphones perfectly… especially considering that everyone’s head and ears are different. Sounds impossible. I was kinda skeptical about technical measurements before because they do not perceive sound the same way we do, but then there is no way to test headphones with a “universal” human ear, so I think the best we can do is use technology to get measurements. It’s an overall complex subject, and unfortunately not as many are trying to get it right.

I am not about graphs, so it’s hard for me to understand it all. Also, it’s not a particularly popular headphone, so I cannot get my hands on many FR measurements. One of the headphones is the OLLO S4X, I’m pretty sure I saw one FR here on hifiguides. The other one is a Direct Sound headphone (I believe the EXTW37)

anyone who says studio reference headphones should be completely flat is kinda doing a fantasy on themselves, flat headphones are really good if you are in the mixing room, but even then its not needed if you are a production person. Billie Eilish’s brother Fineas did all the mastering and mixing for her debut album on audio technica M50X’s, the Beyerdynamic DT 770s are very well regarded in studio scenes and they are HIGHLY V shaped, and sure flat headphones for studio reference are there, but there is hard competition in the sony 7506


Fair point. I do know of Billie Eilish and it’s amazing what she and her brother are doing.

When it comes to music, it’s the least about the equipment… especially speakers/headphones. Those are just fine details that one may care about due to perfection, but besides that… no matter how expensive the mic, or the headphone, or the speakers… or anything is, none of it will make you a better musician.

But something that I have in mind is how do I know how balanced a headphone is - for example, the S4X has noticeably less bass than the EXTW37 from Direct Sound, this would essentially mean that you would be putting way more bass if you exclusively used the S4X for producing music… now, of course, a real producer or mixing/mastering engineer will use a normal headphone or car audio system to listen to the final result, this would let him/her know how the normal people will be listening to it. But I guess it’s worth noting things like that

Ooooh! If you can provide a link that would be awesome. Because I can’t even think of what terms to search for.

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that reminds me…

the beat to XO Tour LLif3 by Lil Uzi Vert. a song that people put as one of the best of the decade, was made exclusively on a beats pill because he didn’t have his studio monitor speakers on him… he just mixed the sound to sound good

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That put further meaning to “all my friends are dead”, producer’s monitor speakers were “dead”. I guess the beat maker and Uzi shared the same pain

Something in my aging, decrepit brain just went click. In the link to the abm0 post he refers to Dr David Griesinger and bingo! that’s the guy. Here’s the YT vid, the demonstrations start just before minute 12: And that’s just a demonstration of ear canal variance. I can only imagine what happens when we add pinna and concha variations.


what im saying is that anything can be studio reference

just dont phone it in and adapt to how your headphones sound…

NTR im looking at you stop complaining about people lying about headphones being “professional grade”


For forever now, I have been trying to find the interview where some modern artist said how he literally mixes (or masters, don’t remember) music on a little mono FM radio. That was like nuts to me, his defense was that the music should sound “fire” even to people in prison or in the “hood”, and I never forgot that interview… but forgot who the person was :confused:

Btw, who is NTR?

No Theme Reviews, basically he is trying to do the ASR shit and talk about how “on this song the subbass was not that strong”… mostly as an excuse to get angry at people like audeze and chord and anyone that he will call a shill company who pays zeos and darko for positive reviews (instead of… i dunno, people having different opinions)

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Well then, he probably shouldn’t even use the mono radio. Just jack everything up to 10 and call it a day lol. I’m really curious now who this dumbass is so I can listen to the mess he’s recorded.

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The interesting thing is that his music was one of those very high quality ones, like clearly it sounded above the quality of others, that’s why it was kind of fascinating to hear him say it.
I am assuming he only used it as one of the devices used for mastering and listening to the final mix - I remember him saying that it would reveal any imperfections and things of that sort.

That’s what bugs me… I couldn’t find the interview, and now that it has been at least 2 or 3 years since I remember hearing it, i just gave up on the search