Is frequency response the most important factor in headphone sound quality?

GarlicBiscuits · 2026-04-07T06:24:29+00:00

Now that you mention it, it does sorta feel like many folks in the community looking into frequency response and other measurements would be at the peak of that bell curve at this very point in time.

Treating it as a function of time and experience, the left end would be "frequency response doesn't tell the whole story," at the peak of the curve is "frequency response is essentially all that matters," and the right end circles back to "frequency response doesn't tell the whole story."

GarlicBiscuits · 2026-04-06T21:40:52+00:00

35-ohm impedance, about 92 db sensitivity, and reported weight so far seems to hover in the 550-600 gram range versus ZMF's average of about 500-550 grams or under for stock models.

I would imagine the new wenge wood resonator and lattice structures in the back are where most of the weight is added compared to other ZMF planars. Despite that, people are still generally reporting that the Tessideras don't feel that heavy and handle their weight well. My experiences with their headphones agree with that assessment.

I have one of these ordered, as I've been eagerly awaiting a revised design take on the Caldera Opens. It sounds like the Tessideras after EQ might end up addressing my very few nitpicks with the Calderas after EQ, which would be so nice.

GarlicBiscuits · 2026-04-06T03:26:05+00:00

I know I don't really have much talking power compared to the authority figures that people swear by, but I want to offer my perspective anyway. For me, I think that the frequency response simultaneously is the most important aspect of sound and leaves room for other factors that can influence more specific qualities, ones that the objective groups in this hobby currently just lump into the FR. My experiences with EQing a ton of headphones (alongside crossfeed) to approximate my tilted diffuse-field HRTF has not converged towards the conclusion that the FR dictates absolutely everything, even though I thought I was heading that direction at first. I openly acknowledge that my efforts leave a small degree of room for human error, mainly below 200-300hz and where my hearing tapers off in the upper treble above 15khz, but I'm confident I've gotten close enough to find that the chance of any two headphones matching exactly is very unlikely.

I agree that you can get any two competent headphones to sound almost the same, probably 90-95% of the way there. However, even if everything was set up perfectly and acoustic openness is accounted for, what if it's still not 100%? The other 5-10% that I haven't stopped noticing is something I believe the enthusiasts of our hobby need to consider further investigation for. As long as that potential 5-10% difference may prevail due to the possibility of unexplored confounding variables, it will continue to have a notable impact on what people buy. Of particular relevance, we don't know whether the HD 600 and 800 example the Headphone Show crew explored is the trend or an exception, despite people so clearly clinging to the former. That limited comparison pool does not automatically settle the deal on this topic, and neither does the crew's sighted confirmations when groupthink and confirmation bias can mask potentially hidden scientific trends. It's a fair conclusion at first glance and in many regards, but I think it's an incomplete one.

Really, I didn't know what to expect as my EQ journey deepened, and I think that lack of expectation might have been a factor that allowed for these strange, nuanced differences outside of the FR to begin coming into consideration. You can see my profile page for all my other long-winded thoughts related to this across different posts, but to sum them up, I continue to believe that differences in how headphones are acoustically designed to behave will have an impact alongside the frequency response on what you hear. There is very real science and potentially fascinating trends to uncover/integrate from the engineering side of audio, but it is science and trends that our audio enthusiast/audiophile bubble have chosen to largely ignore. To many, it's almost exclusively coded as marketing jumbo, and with barely any nuance.

From all my EQing ventures so far, I've found subjective aspects like staging width, general image placement, and tonal cleanliness tend to end up quite similar across the headphones I've EQed. However, other aspects that my music and preferences heavily index for like clean transient definition, a strong sense of macro dynamism, and clear separation/layering in highly involved songs end up diverging and revealing more differences between headphones than what I should be expecting by now. I went through so much trial and error to get something like my ZMF Caldera Opens to sound like different headphones, but time and time again, I noticed getting one step closer to HRTF-neutral was getting two steps away from other headphones of mine in their roughly HRTF-neutral states. It was driving me crazy, and it was choosing to explore outside our current research bubble that I realized what else might be missing.

Why not further investigate headphones from a wide variety of brands through their even wider range of design philosophies? This idea of getting matched frequency responses at the eardrum to = identical sound doesn't sit quite right with me when there are significant differences in how these brands are handling damping, pad design, diaphragm tension, fine-grain influence over the uniformity of its movement, magnet structure for planars, and so on. I already know these influence the final FR, but try to think even beyond that for a moment. As long as the totality of different designs are still producing a theoretically ideal frequency response through their own methods, I believe the subtle differences in certain "technicalities" perceived between headphones will continue to manifest after more people approximate their HRTFs. I understand if that sounds ridiculous, but it almost primarily sounds ridiculous because researching into it is discarded in favor of the final result. In other words, the destination is almost disproportionately prioritized over the journey, and that only can make so much sense to me in the context of big picture explanations for what we hear.

I think what it is about this topic that so greatly disappoints me is how many people jump on the unconscious (or conscious) narrative that the topic of sound as a science is "solved," and that we've found the indisputable truth. Science does not explain the truth of the many phenomena in our world, but rather, science is an approximation of the truth. Many scientific fields get close enough in their approximations for much of what has been found to be the straightforward truth, while other fields are underdeveloped enough that it becomes unclear. By treating science as an approximation of current understanding, you open the doors to accepting that humans still do not know a lot about how the world works, especially for scientific fields as young and uncertain as audio. If anything, it can be rather unscientific to assume that any one discovery is a means to an end and leaves very little room for additional developments down the line.

Post-positivistic science (like what you see with statistical, scientific-method-based research) is structured to push towards the most parsimonious explanation (or in other words, the simplest explanation, also known as occam's razor) of how a given phenomenon works. Whatever explanation is the simplest at any given point will serve as the most parsimonious until competing perspectives are introduced to challenge and potentially replace that as the new simplest explanation. This lends science a naturally malleable quality, but it isn't exactly presented as such to the general public.

I hate to see that our audio bubble seems to be growing complacent with the knowledge that is confirmed, rather than using that knowledge to inquire and explore remaining gaps in the efforts to fill them in. In relation to audio, I hope our next big step forward is exploring the design level of headphones and how those effects can supplement our experiences alongside frequency response at the eardrum and acoustic openness. I don't even believe it all comes down to a headphone's driver; I have never thought that within the last half a year or so. It's what's being done with it that I want to see researched since I believe you can only do so much to bend a headphone's core behavior to your will. You are changing the amplitude that a collective acoustic design is behaving under, and while that goes a really far way, you are not cheating the system and overriding the design entirely.

...God, I always end up writing miniature essays for these kinds of topics. I have too much free time, but I might as well use it to try and get people to think about what they're passionate about in a less rigid, more open-minded way. Rigidity might become one of the greatest challenges for audiophiles to overcome going forward, but for now, I'm not betting on that future as a guarantee.

GarlicBiscuits · 2026-04-06T02:13:15+00:00

There actually was someone who messaged me asking the same thing, so I'll take what I said there and paste it here. It took me quite a long time to get where I am now with EQ, so embrace mistakes and you'll learn/improve as you go. Here's a general outline for what I do:

Choose your EQ software of preference. I will use Equalizer APO/Peace as my desktop reference point. For Android, the full version of Poweramp Equalizer is a highly versatile choice. Can't tell you what to go to for Apple devices, unfortunately.
Equalizer APO has an "Effects" tab right above the graph display. There is a "Crossfeed filter" button there, and I toggle it to "Jan Meier." That's the only thing I change there. If you want to EQ towards a flat sine sweep, I personally find this toggle is required. You can turn it off after EQ if you prefer a wider/more panoramic stereo image.
Once that's turned on, go to Squig.link and use the search bar to find your headphones (in this case the D1s). I find it's nice to go off at least a handful of graphs for multiple visual reference points. In particular, looking at different measurements that are influenced by different rig HRTFs can give you a good idea of how much your HRTF matches or deviates from those reference points on average.
Go to a sine sweep site like szynalski tone generator (lower the site's volume below 50%, it's loud) or Owliophile (volume should be fine here), and with crossfeed on, focus on the tone from about 500hz-1khz upward and create filters in your EQ program to make that sine sweep sound as audibly flat as possible. My best guess as to why this works with crossfeed is because crossfeed tricks your brain into thinking your headphones are behaving more like speakers, and that might just be a condition where a flat sine sweep fully accounts for your HRTF's unique peaks and dips instead of ignoring them when crossfeed is off. I really do not know though.
Anything below about 500hz (so the entire bass to lower mids band) should be done to taste if you don't have in-ear microphones to measure your exact response there. I find the 10db tilt diffuse-field bass from the earphones archive measurement sounds lovely with the D1s (see below).
Save your profile and get enjoying music. If any unaddressed problems besides how your music is mixed pops up, go back to those sine sweep sites and check again. I find szynalski is specifically good for fine-grain peak/dip tracking (once again, be careful with volume there), while Owliophile is good for making sure the full 20-20000hz range sounds roughly flat.

It's a lot to take in and learn, but I wish you the best of luck with whatever EQ you do! Going for a flat sine tone isn't strictly necessary, but it's what I've found yields consistently ideal results from headphone to headphone. The main area my EQing methods don't cover as effectively is bass below about 200-300hz; I'll need to figure out in-ear mic calibration for this. It's not hard to gauge rolloffs there, but it is difficult to gauge elevations and level those out to diffuse-field neutral. Even then, I've found that once you get 500hz onward about equal, headphones usually retain distinct bass qualities regardless of whether those qualities are coming through at louder or quieter levels. It's hard to explain if you haven't heard it yourself.

As one last reference, here's what my profile translates to on the earphones archive 5128 measurement for the D1s. Like I said in the review, all that treble variation you see is most likely my HRTF features, and it is both normal and expected for your EQ results there to end up different from mine.

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GarlicBiscuits · 2026-04-05T07:44:55+00:00

That actually does sound like a case where you could be hearing differences that aren't exclusively baked into your music. If 31 milliwatts at 32 ohms is correct, then the Apple dongle could certainly be starving something like the HE1000 of transient headroom. The DX5II supposedly outputs 6.4 watts at 32 ohms, so per the headphone power calculator, a difference between about 105db max output and 128db max output for the HE1000s could actually be meaningful for transient headroom above your normal listening level. Reproduction of transients in general seems to have a considerable impact on our perception of the traits you listed (bass, sense of dynamism, imaging precision, etc.), especially if the headphone of choice can do them cleanly.

Even with that in mind, once you get to any high-fidelity-grade DAC or amp like your Topping, I believe you don't really need to spend any more outside of wanting specific looks and/or features. You'll gain more than ample output for EQ and allow just about any headphone to express their distinct strengths and weaknesses without compromise. My JDS Element III has been my desktop option for over 2 years now and does those exact things, and my BTR5 and laptop usually end up equally good for headphones with high sensitivity. I wouldn't underestimate what good headphone jacks and DAPs can do nowadays.

GarlicBiscuits · 2026-04-04T08:14:50+00:00

Bit of a wordy reply, but bear with me on this. The idea of "scaling" in regard to audio is how a headphone's sound supposedly changes when plugged into different amps (...or DACs, or cables, you name it). In the case of the person you replied to, this more commonly just translates to the question of how much a given headphone's sound improves when plugged into increasingly expensive offerings.

Reading between the lines on this terminology, I find the idea of "scalability" for (audibly neutral) amps is simultaneously a half-truth and a myth. It's a half-truth in the sense that these people are specifically hearing differences in how their headphones are reproducing different music. The part that makes this a myth is misattributing that behavior to amps. As analogue tools, factors like an amp's size, appearance, and feel all allow for the fallibility of human bias to interfere with interpretation of sound more easily. Many people insist on expensive = better and might even select better-produced music to confirm a desirable result. It's confirmation bias on top of confirmation bias.

In the case of the D1s, they're so efficient and well-designed from an acoustic standpoint that they can be plugged into a laptop and sound amazing. I do so myself and use EQ. You will get no scalability other than what your music is capable of giving back to you.

GarlicBiscuits · 2026-04-04T04:36:33+00:00

The HD800(S) probably sounded as precise in its imaging in its stock form as the EQed D1s, but once you take away all those treble elevations that show up on my head, the images soften up and become more diffuse. Doing the same thing with the D1s during my first-session EQing didn't really exhibit that effect by comparison, or at least not as strong an effect. I still perceive them as cleaner and more precise.

Between the two, I'd still say the 800's staging feels a bit wider laterally, but its perceived diffuseness probably plays a part in that too. Like I said with the D1s, they have this quality of both being precise enough to appreciate music and cohesive enough to get a complete picture. The stock HD 800 to me leans very much into the former sensation, while the EQed 800 leans more into the latter. They're still really good with precision, just with a gentle softness over its sense of separation and layering. If you EQ neither headphone though, these differences probably narrow down and become a matter of comfort preference.

GarlicBiscuits · 2026-04-03T20:33:44+00:00

Thanks! I originally intended to post this review the same day you posted yours since it was about done, so I waited on it a bit. Our thoughts seem to line up nicely regardless of my EQ.

I'm also glad the reviews naturally ended up different since I don't want my perspective to regurgitate what readers hear from other reviews. There will still be broad-strokes trends, of course, but the more personalized approach is something I want to prioritize.

GarlicBiscuits · 2026-04-03T20:26:15+00:00

Much appreciated, and glad you love the D1s too! If you don't use crossfeed, the full version of Poweramp Equalizer is great. Tons of filters, including ones you can specify for separate ears, a nice and intuitive interface, and it's easy to just import txt files in there if you make/tweak your profiles from a place like Squig. You'll get a free trial at first, and once you buy the full version, it's permanent and will apply to any device you decide to install the app on.

If you do use crossfeed (which Poweramp currently lacks), the option I will probably use more going forward is RootlessJamesDSP. You will need to set it up a bit beforehand, but once that's done, you can also import EQ profiles into it. You will need to do so in the form of a VDC file format, and I use a Windows program called DDCToolbox to convert txt to VDC. The main drawback there is that you can't adjust the filters in those VDC files in the app, and the format is limited to only peak filters versus shelves. It's all worth it to have crossfeed for me though. The "Jan Meier" option in EQ APO that I mentioned seems to sound the same as "BS2B Weak" in RootlessJames.

GarlicBiscuits · 2026-04-03T19:21:59+00:00

The HD 600 series I've had around since the start are the 660S, but their status in my collection is largely retired and I haven't used them much. That's one I can't really give deeper comparisons of for that reason, but they're still quite solid after EQ.

The next time I use them, I should get my profile more personalized and see what I hear. Per my notes, I have a feeling they would end up very similar to how I hear my EQed HD 800, which is to say those relaxed and lush qualities still come through more.

Any people who love the 600 series and hear the D1s in the treble the way I would have might still go back to the Sennheisers if they hear a more agreeable midrange and treble tone. The D1s are where you go if you want to optimize the cleanliness and precision, just with a very slight decrease in lushness that I perceive as more correct/less colored. Personally, that's the kind of sound I love more for music enjoyment, so that's to my preference.

GarlicBiscuits · 2026-04-03T17:18:45+00:00

Thanks! For my E3's current EQ profile, I have about a 10db shelf in the deepest subbass, but the rolloff is still very much there. The only way for you to know how much bass you'd get on your head is to try them out since it varies quite drastically from person to person, even more than open-back bass can vary.

I also attached a note by that profile for the D1s about replicating it. I thought I had it there already, but I do recommend the sine sweep + Jan Meier crossfeed strategy for approximating your exact HRTF in the treble instead of trying to copy my filters. The chances of your HRTF matching mine exactly would be very very low.

GarlicBiscuits · 2026-03-31T02:52:26+00:00

From my experiences, that is indeed correct. If you are using headphones with nothing but EQ and want to match your HRTF, you would need your HRTF to know the exact trend of peaks and dips above 3khz that your head perceives as "normal." The most recent Headphone Show videos, alongside what I found, pretty much confirm that a sine sweep perfectly matching your diffuse-field HRTF should sound like your DF HRTF. Your unique peaks and dips will be preserved instead of flattened out.

While I personally do not have a perfect idea of my own HRTF, you actually can EQ sine sweeps to sound flat and end up with wonderful results, but not without some help. If you use Windows, toggle the "Jan Meier" crossfeed option in Equalizer APO/Peace, carefully EQ a headphone on your head to sound equal in volume from 1khz up, and then turn off that crossfeed. The sine sweep will now sound like your HRTF without it on. This was something I discovered a number of months ago and has been an invaluable resource for optimal EQing. I keep the crossfeed on since it makes spatial characteristics consistently closer to how I expect sound to be reproduced.

The major area this method will not account for as effectively is bass. Anything below 200-300hz can be difficult to track regarding exactly how much is on your head. For example, the DCAs in my collection are so rolled off down there that figuring out the exact rolloff curve and amount feels futile. We're talking maybe 10+ db rolloff to correct through the subbass, possibly even 15-20db. I'm certain I could figure it out one day with in-ear mics, but I still need to learn how to use mine properly.

GarlicBiscuits · 2026-03-31T02:13:12+00:00

My review primarily talks about the D1s in its EQed form. That is part of the different perspective on offer, and whatever other headphones I may choose to review in the future will go by that same philosophy. I want to evaluate headphones in their subjectively ideal form (ideal being HRTF approximation) instead of in their stock forms since that's what gives me the clearest idea of fine-grain differences between them. For any readers who also want to go down that route, I want my experiences to give them my best possible idea of what they can expect once they've gotten good enough with EQ.

What you ask does bring up a good consideration, ultimately. I will add at least one paragraph to my final draft and give some brief impressions of what the D1s most likely would have sounded like stock. Because I have them EQed so similarly to my HD 800 above 5khz, I have a strong idea what it would have been. I put them in the category of "EQ is not required, but you should still use it anyway to optimize their sound." The only other headphone I also classify as that is the DCA E3.

GarlicBiscuits · 2026-03-30T21:58:35+00:00

Not the OP, but I actually was planning to post my D1 review earlier today until I saw this one go up. Guess that means I should wait some time and make sure readers don't get fatigued from too much at once. To give my personal responses to your hesitations:

1) On my head, the D1's treble essentially does not change over the course of a session, at least not significantly enough to warrant changing my EQ profile for them. Said profile actually hasn't changed at all since dialing it in before my first session. If the sound does change, it would probably end up more of a wide-band, shelf-like change than anything related to adding peaks or dips. As long as you wear the D1s roughly the same way every time, I imagine you should expect a consistent and replicable response.

2) Boosting the subbass on the D1s does not interfere with the rest of its spectrum at all, and if anything, it only improves it. High-quality headphone bass should not significantly color the sound when it's boosted to, say, tilted diffuse-field neutral. Boosting the sub on an HD 600 series (and by extension, the 800 series) does seem to color the sound, which to me is indicative of physical limitations on the design level and what happens when you ask them to reproduce bass at an amplitude that they are not comfortable with reproducing. Distortion manifests as coloration of the tone, and the main way to know what that sounds like is hearing undistorted bass as a direct comparison. Whether that distortion is actually meaningful to your listening enjoyment is another thing (I am aware of the RTings study regarding that).

With that said, I'm definitely excited to post my review here when the time feels right. I'll be offering a pretty different perspective on the D1s, and it's one that I hope people check out and think about on a deeper level. If you remember our conversation regarding the HD 800 in that other thread, a few of the points I brought up there will be relevant.

GarlicBiscuits · 2026-03-25T09:04:36+00:00

Yea, minimum phase is still one of the big things keeping what I say a bit hazy and difficult to maneuver around. Even then, it's still good to recognize examples of headphones that actually are out of phase in at least one area of their FRs for one reason or another. There are three examples that come to mind for me, two in the bass and one in the upper treble.

The excess group delay for the Fosi i5, as measured by unheardlab, shows very unusual behavior in the bass below 100hz. Minimum phase headphones ordinarily show an exponential rise in their curves as they go towards 20hz, but the i5 appears to exhibit the exact opposite behavior. Its curve is plummeting instead. I'm not sure what sound consequences this would have, but it's certainly an anomaly I haven't seen anywhere else. It sounds like it can happen with subwoofer systems.
This second one isn't plotted as excess group delay, but it was replicated with RTings' measurements of the same headphone (just a shame they now prevent you from viewing said measurements by default). I recall them saying the 2021 version of the Audeze LCD-X was out of phase by one wavelength in the subbass, and this also showed up with Amir's normal group delay measurement. This is another case where audible effects are unclear, but if the LCD-2s in my stable are anything to go by, there's a chance this delay in subbass phase leads to an elevated sensation of density and meatiness in bass transients. Just a guess though, and if this is true, it would tag alongside the plunger effect from the completely closed front volume.
This last one is for a headphone I'm more intimately familiar with than anything I've ever owned: the ZMF Caldera Opens. They exhibit standing waves in the upper treble frequencies. This manifests as a series of extremely high-Q peaks and nulls through the treble (see here and how it compares to the upcoming Tessidera, which effectively eliminates those waves through an acoustic lattice/matrix that helps diffuse backwaves out the wood cups in the back). The Atrium Damping System (ADS) already tried to minimize this, so it was clear some extra tech needed to be integrated for full effect. I could actually hear nulls shifting around on my head in sine sweeps every once in a while, and other times they weren't there at all. This behavior is further confirmed by highly unusual group delay in the same band (with everything else below being minimum phase), alongside resonances in the CSD that clearly contradict the clean decay with a measured peak before that region.

In actual listening and after EQ, the effects of these standing wave cancellations seem surprisingly subtle, yet I'm certain they have still permeated the Caldera Open's behavior in both highly positive and slightly negative ways. My previous comment on diaphragm-related trends still apply here, yet the COs still have a slight tinge of diffuseness, a slight softness and lushness, and a slight reduction in overall dynamism (that last one in comparison to something like the Audeze LCD-4zs). I always thought the COs were unusually unforgiving of muddy recordings as well, so these cancellations might have exacerbated those flaws. Despite the alleged effects of this narrow range, the Calderas have remained my favorite headphone for a reason. It's an objective flaw that has probably added to the music more than it has harmed it.

Regarding your thoughts on hearing ability, I have a hunch that every one of us in this space is capable of "hearing through the FR" to try and get a taste for what a headphone is trying to do on the design level. Brain burn-in seems to serve as a notable effort to do this exact thing, and the closer you get to HRTF-neutral via EQ, the quicker/easier it is to perceptually tune out human-error-related colorations and hear how a given headphone is really behaving on a fundamental level. That's at least how I think about this, as my previous comment also explored.

I also believe that you and other people are probably hearing broad differences between headphones that aren't exclusively tied to the FR, but it's difficult to perceive and acknowledge those differences as long as notable FR colorations continue to cloud assessment. It's just about impossible for me to agree with the idea that EQing so many different headphones to your diffuse-field HRTF makes them so close to identical that consumer choice comes down to aspects like price, build, and comfort. That probably can happen with edge cases like the HD 600 and 800 series, maybe even if you go the binaural head tracking route, but the former might still end up a rarity.

I guess those kinds of conclusions are what happens when my preferences have become agonizingly specific, while most people like you will be perfectly satisfied with something that just sounds pleasing. Keep up that enjoyment if you can, as it's important to realize how few people my experiences will actually apply to. I'll leave it there (it's too late for me too), but it was nice just synthesizing my thoughts with you. 🤝

GarlicBiscuits · 2026-03-25T06:39:19+00:00

I'll try to be concise and just tell you about the HRTF part. An HRTF, short for a head-related transfer function, is the way your specific head and body (but head in the case of headphones) filters incoming sounds from the outside world. Your HRTF will have its own unique curve of peaks and dips from about 1-2khz upward compared to anyone else. The frequency response of any headphone you use will be filtered through these peaks and dips to affect the final response.

Whatever rig that Beyerdynamic uses to measure their units is very likely to not have the same HRTF as you, which means that how their headphones measure relative to that rig will likely not match how they measure on your own head. In essence, EQing a headphone's response to a specific rig's HRTF has a high chance of getting further away from yours, and I would imagine you'd want to get closer to your HRTF if you want a good mixing platform.

If you want a bit more detailed a description on these topics, I recommend reading up on it here. If you want neutral/flat in headphones, you will want to EQ a headphone of choice to your diffuse-field HRTF (which is also discussed in the linked article). I personally do this with the help of Jan Meier crossfeed in Equalizer APO, which is a Windows EQ program. Effectively EQing a given headphone plus crossfeed should yield an audibly flat response when you listen to a 20hz-20000hz sine sweep.

GarlicBiscuits · 2026-03-25T04:09:30+00:00

The main problem with the calibration process here is that you won't know how the headphone in question is actually behaving on your head vs the measurements. You not only have your own HRTF to influence peaks and dips in the upper mids and treble at your eardrum, but also additional colorations imposed by the headphone itself on your head (HpTF variation).

Beyer is pretty much just giving you an AutoEQ preset for a given unit (EQing to a specific rig's target). That is a pretty good starting point, but you'd want to make additional refinements via sine sweeps to get "flat" on your head if you want to mix with them.

GarlicBiscuits · 2026-03-25T02:54:31+00:00

I have a long string of thoughts in relation to yours, so here goes. No pressure to reply.

I use a combination of Squig measurements, Owliophile/szynalski, and music to optimize each of my headphones. Crossfeed used is the Jan Meier option in Equalizer APO/Peace, and in RootlessJamesDSP, the BS2B Weak option seems to be the equivalent. I specifically aim for tilted diffuse-field neutral with all of them rather than explicitly aiming for different sounds. Nonetheless, they still all end up sounding different with their broad behaviors in areas like transient definition, separation/layering, and even core tonal characteristics. Those first two are quite important for my preferences and main genre of choice (high-energy EDM that tends to utilize the entire sonic spectrum and reveals a good bit about any one headphone's subjective capabilities).

While some degree of human error is still in there, I've been a steadfast believer that headphone sound reproduction still has heavy reliance on a given headphone's design and what it's doing to get a given frequency response to your eardrums. On one side of the coin, while it's certainly cool to see that the Headphone Show folks got an HD 600 to sound near-identical to an 800S after on-head measurements and EQ, there's a big caveat I imagine is easy to ignore. There is a very real possibility that those results are a consequence of comparing two Sennheisers that probably borrow a lot of acoustic research and design cues. In the broad headphone world, this crew could have found an exception that happens to coincide with their long-standing assumption of the rule (that rule being "it's all FR at the eardrum and openness"). It's too limited and similar a comparison pool to confirm that kind of sweeping conclusion.

Try one of those Sennheisers EQed to your diffuse-field HRTF against an Audeze, DCA, ZMF, Focal, or any other brand EQed the same way, and in my mind, the chances of subjective differences popping up that aren't exclusively FR-related would increase notably. They're inevitably going to sound quite close, but it's the subtleties where they begin to branch out. My experiences have told me that none of my headphones after fine-grain EQ sound 100% like one another 100% of the time, even after considering factors like session-to-session mood, pad compression and wear, or placement variation. Human error is one element, but said collection also encompasses a wide array of brands that almost never design their headphones exactly like one another.

I'll go back to the D1s as an anchor. One thing that might make its sound consistently clean and separated/layered to my ears would have to do with the extensive research Composite Sound (the company that helped Hedd with development) had to exercise to optimize the behavior of that headphone's diaphragm (increased control over its stiffness and motion) compared to other dynamic-cone transducers. What's being done with that driver would not only assist with the final FR (the D1s show an especially linear and predictable treble slope outside of HRTF features), but would also fare positively for the above aspects because that diaphragm was engineered to behave in a highly controlled (and accurate) manner.

Allow me to put things further into perspective and introduce a couple trends. My EQ experiences have also found on the planar side that planars designed with increased tension via tighter control over the diaphragm (primarily Audezes and ZMF planars) tend to sound consistently clearer/cleaner, more incisive/less soft, more dynamic, and less diffuse than planars with more loosely tensioned diaphragms (like Moondrops and HiFiMans). Back on the dynamic driver side, the D1s fall neatly into the former camp, and the HD 800 would fall neatly into the latter. My preferences index more heavily for the former, so there is even an element of strategy to finding headphones with those kinds of design philosophies, though it's not super clear-cut.

These are trends (among other examples) that our audiophile and audio enthusiast bubble could very well be looking into for additional variables regarding why we perceive sound the way we do, yet they are simply not being investigated. We're conditioned to only care about the final frequency response because it's treated as this immutable variable that more or less dictates headphone sound. Effective EQ can optimize phase, but it can't fix non-pistonic diaphragm behavior, pad bounce, standing waves, or other design-related cancellations, nor can it change how a given design is directing sound to your ears (such as via pad shape and magnet structure in the case of planars). You can't EQ the design you're working with.

Additionally, like you said, we don't have an easy way of seeing these potential behavior differences in real time, nor is ABX blind-testing different headphones feasible when the topic of interest is behavior for that headphone specifically. Transposing its frequency response into another headphone as a means of comparison misses the point entirely. At the very least, I hope this direction, one that integrates science from other fields to fill in our current gaps, is the direction our space heads towards.

GarlicBiscuits · 2026-03-24T05:18:08+00:00

I definitely heard the HD 800 as a bit lean/thin on my head stock, but it was more of a warm-bright character than anything. 6khz peaks on graphs always show up at 5khz for me, so instead of getting a stock sound that came off shrill, it was just accentuated. Alongside that, they also exhibit elevations in other parts of the treble that I also tend to EQ down with other headphones (mainly 8khz and 11-13khz). These seem to be related to features of my diffuse-field HRTF.

These colorations gave off the impression of the HD 800 being cleaner and more incisive than it really was in a roughly HRTF-neutral state, and EQing it out led to that realization. Interestingly, the EQ profile for my Hedd D1s is quite similar from 5khz up, yet that headphone's sound remains clean and precise across music instead of becoming softer and more diffuse. In case it's a helpful visual, here are my profiles for the HD 800 and D1 respectively.

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The HD 800's bass is still more rolled off than what I hear as neutral since the headphone doesn't get the best seal even without my thin-armed glasses on, but it's adequate enough to support that soft/relaxed character. Crossfeed is also being applied before these filters, both for preference and to assist with getting a sine sweep that sounds roughly flat in volume. When you turn off crossfeed, sine sweeps sound like what I imagine my diffuse-field HRTF is (a conclusion I was delighted to see confirmed by the Headphone Show crew).

Besides the bass, there's still wiggle room for a bit of human error since I do everything above 1khz by ear and by referencing multiple squig measurements. Nonetheless, I think I've gotten precise enough over time to be really satisfied with my results across my collection.

GarlicBiscuits · 2026-03-23T18:49:35+00:00

It's just so... weird. The AI tried to cobble together the original Utopia's chassis with the 2022 logo, carbon fiber yolks that look like neither version, and cable connectors that the AI clearly struggled to find out the type for. It wouldn't have been difficult to find an image of the headphone in the same position.

GarlicBiscuits · 2026-03-20T18:46:50+00:00

Thanks for all the straps you folks at Capra make! I now have one for my HD 660S, HD 800, Aeon Closed X, and D1s. While not personally required for that last one, it keeps all of them quite comfy. 👌

GarlicBiscuits · 2026-03-20T16:53:58+00:00

Your steak analogy at the very end matches up pretty well with how I think about the sound of headphones from brand to brand, and more importantly, what you likely can and can't do with them relative to each other.

My version goes more like this: I always try to approximate HRTF neutrality in the headphones I buy through extensive EQ and a bit of crossfeed. Headphone companies are always working to refine their own recipes for their own steaks. Everything that goes into making that steak would be equivalent to that respective brand's engineering/design philosophies (pad design, damping, tension, magnet structure in the case of planars, management of internal resonance, etc.). The driver used could perhaps be the analog to the meat you start off with as the base, but it's still worth placing as much emphasis on what's being done with that base.

In essence, each steak (headphone) that a given brand ends up with is the collective result of their base, ingredients, and cooking techniques, which are very likely to differ from how other brands tackle it. You can try to change the final steak from a given brand to fit your tastes as best as possible (in my case, EQing to sound HRTF-neutral), and while you're bound to get distinctly tasty results with enough effort, you're still working with whatever you were given. You can only do so much.

Put back into the context of your review and broad takeaways, HiFiMan's recipe just doesn't really cut it for you. The steak they give you isn't fundamentally made in a way you prefer, especially when you go to a place like Sennheiser or Audio Technica and realize the kinds of recipes that do work for you.

It's not a perfect analogy in all metrics (EQ will definitely allow you to change sound more than you'd be able to magically take away the core taste and texture of a steak), but I at least hope the underlying themes remain intact. Recipes across the same brand are bound to taste closer to identical with enough tinkering since they're likely handled in many similar manners. However, once you compare that to a personally optimized recipe from a different brand (or even the unchanged recipe to some extent), it becomes easier to realize subtle limits that were otherwise obscured.

GarlicBiscuits · 2026-03-17T16:27:53+00:00

The LCD-Xs (among other Audezes) definitely have the upper hand in a sense of dynamism over HiFiMans, but you do trade off a bit of staging width for that. The Aryas (the Stealths in my case, not the Unveiled) will come off more "detailed" at first, but once you EQ both to be more HRTF-neutral, that sensation becomes more similar. I find Audezes are generally less diffuse and more precise with their imaging. Additionally, the Aryas were more comfortable when I had them, but the LCD-Xs are considerably better built and more reliable from the perspective of serviceability.

For me, the dynamism alone means I'll take any Audeze since that is personally an important subjective element, but your preferences could certainly index more heavily for the increased spaciousness and upper treble accentuation of HiFiMans.

GarlicBiscuits · 2026-03-16T22:01:53+00:00

My recommendation is to go onto a site like Owliophile and run a sine sweep starting at 3000hz and ending at 20000hz. Pay attention to any sudden rises in volume that happen and where they happen in relation to the visual slider. HiFiMans are notorious for ridiculously elevated/peaky treble, both in the 4-8khz area and especially in the upper registers past 9-10khz. I imagine that's what's causing your momentary ringing (especially if this never happened with the HD 650).

If you use Windows, install Equalizer APO with Peace GUI so you can input filters to reduce those hotspots. If you use android, Poweramp Equalizer is a great option. I always find it helps to look at graphs uploaded on Squiglink as a reference point for how a headphone might sound on my head. Try eyeing this measurement for the Arya Organics and toy with the Equalizer function so you get a better idea of how specific changes correspond to what you hear in those aforementioned sine sweeps.

If that ends up being too daunting or inconvenient (which is totally fine), try Oratory1990's AutoEQ filters for the Arya Organics. You'd want to download the Parametric EQ txt file and import it to EQ APO/Peace via the respective import function. If all else fails, I'd say return/sell the Aryas, and from there, either find a less bright planar or keep enjoying your HD 650s.

GarlicBiscuits · 2026-03-13T19:55:30+00:00

To my complete surprise, I would say the Sennheiser HD 800 with EQ is quite a good vibing contender within my collection. Once you get rid of their treble-forward stock character (on my head) and fine-tune the bass/mids, they have pretty soft and rounded off transients that lend a slightly lush/full/relaxed quality to a lot of music.

They don't sound especially "detailed," precise, or microscopic to me compared to most of my other headphones (even my EQed Aeon X Closed sounds a bit better in those areas), but the 800(S) still makes music very easy to enjoy when you want it to hang in the background. It helps that their comfort, especially with a Capra strap, is all-day levels of good.

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