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target.md

Overview of Popular Target Tunings for IEMs and Headphones

Introduction: In the audiophile world, “target tuning” refers to a reference frequency response curve that designers aim for when voicing headphones or in-ear monitors (IEMs). In simple terms, it's a goal for how the audio should sound across bass, midrange, and treble. Different target tunings have emerged from scientific research, professional standards, and community preferences. Each target has its own sonic flavor and impact on the listening experience. Below is a structured overview of major target curves – both industry-developed and enthusiast-created – along with their general sound characteristics, suitable genres, and why ultimately tuning is a subjective matter.

Professional and Scientific Target Tunings

Harman Target Curve (Headphone & IEM)

  • Background: The Harman target is a science-based curve developed through extensive research by Harman International (led by Dr. Sean Olive and team). It was derived by asking listeners in blind tests which headphone sound they prefer, using a reference of a flat-measuring speaker in a good room (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?) (What is Harman Curve? - HeadphonesAddict). The result is a curve that mimics the sound of speakers in a normal room, including a bass boost (since rooms naturally amplify bass a bit) and a slight dip in upper treble (since rooms absorb highs) (What is Harman Curve? - HeadphonesAddict). There are versions for over-ear headphones and for IEMs – the IEM Harman target typically has a somewhat higher bass boost than the headphone version, because listeners in Harman’s tests preferred more bass with in-ears.
  • Sonic Characteristics: A Harman-tuned headphone/IEM usually sounds warm in the bass, balanced in the mids, and smooth in the treble. Bass is elevated relative to a flat measurement, giving music a rich and punchy foundation. The midrange is generally neutral, with a prominent peak around ~3 kHz (the “ear gain” or pinna region) to keep vocals and instruments clear and forward (Moondrop Blessing 2 – Page 2 – Twister6 Reviews). Highs are present but not overly bright or harsh, aiming for a natural amount of detail. Overall it’s meant to be a “crowd-pleasing” neutral: bass and treble are slightly emphasized so music sounds lively, yet the response isn’t wildly exaggerated in any area.
  • Listening Experience: This tuning tends to work well for a broad range of genres. For example, pop, rock, hip-hop, and electronic music benefit from the solid bass (for beats and rhythm) while keeping vocals and synths clear. Jazz and classical also sound good since the mids are neutral and treble is polite, though very purist listeners might feel the bass is a touch above “true neutral.” Many find Harman tuning to have an engaging, full-bodied sound that still preserves detail. If you’re new to audio, gear that follows the Harman target will likely sound “just right” or natural on most music.
  • Notable Examples & Adoption: The Harman research has influenced many manufacturers. Headphones like the AKG K371 and K361 were explicitly tuned to the Harman curve and are often cited as achieving that target (What is Harman Curve? - HeadphonesAddict). Many modern IEMs and headphones lean toward this profile even if not exactly on target. Because it’s based on listener averages, the Harman curve is often used as a benchmark in reviews – some publications and reviewers consider deviations from it as a sign of coloration (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). However, not everyone’s ears agree with Harman: in Harman’s own tests about 64% of listeners preferred the Harman tuning, while 15% wanted more bass and about 21% wanted less bass than Harman provides (What is Harman Curve? - HeadphonesAddict). In other words, it’s a very useful baseline for a pleasing sound, but individuals may still tweak the bass or treble to taste.
  • Summary: The Harman target gives a balanced, room-like sound – generally warm, punchy, and clear. Great for an all-round enjoyable experience, it’s often recommended to newcomers as a starting point for what “good” sounds like. Critics of the Harman tuning sometimes describe it as “boring” or too safe (SoundStage! Solo | SoundStageSolo.com - Are There Valid Objections to the Harman Curve?), or debate whether it’s truly neutral. But even those critics usually agree it’s a reasonable reference for neutral-ish sound (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). In practice, many listeners appreciate Harman-tuned gear for long listening sessions without fatigue. Just remember that it’s an average preference curve – your ears might prefer a bit different balance.

Diffuse Field (DF) Target

  • Background: Diffuse field tuning was an earlier standard for “neutral” headphone sound, developed by acousticians in the 1970s–80s. The idea is to make headphones sound like you are listening in a diffuse sound field – i.e. a room where sound comes equally from all directions (fully reflected). In a diffuse field, the ear receives a lot of indirect sound, which affects the frequency response at the eardrum. A diffuse-field equalized headphone is thus tuned so that, at the eardrum, it matches what flat speakers in a reverberant room would produce (What is Harman Curve? - HeadphonesAddict). In practice, this means calibrating the headphone to an international standard curve (often associated with ISO/IEC standards) on measurement rigs. Historically, many studio and monitoring headphones (and the classic Etymotic IEMs) were designed around the diffuse field target.
  • Sonic Characteristics: A DF-tuned headphone/IEM is often perceived as very flat through the midrange and somewhat bright in the treble, with less bass presence than Harman or consumer targets. In fact, one source notes that the diffuse field curve is “near flat but with a brighter treble” in its tonal balance (What is Harman Curve? - HeadphonesAddict). Because there’s no extra bass boost to simulate room gain, the low frequencies on DF headphones can sound lean or lacking impact. The treble is usually crisp, even a bit elevated, because the DF standard calls for certain peaks around 2–3 kHz (pinna gain) and additional presence in the 5–8 kHz range (What is diffuse field equalization | Headphone Reviews and Discussion - Head-Fi.org). This can make DF-tuned gear sound very detailed and airy, but to some listeners it may also sound thin or harsh.
  • Listening Experience: Diffuse field tuning is often preferred by those seeking maximum accuracy or a reference sound. For instance, mixing engineers or recording professionals might use DF-aligned headphones (like the classic Beyerdynamic DT 880 Pro, AKG K240 DF, or Etymotic ER4S IEM) because they want a brutally honest balance (What is Harman Curve? - HeadphonesAddict). When listening to music, a DF headphone will present recordings with no added warmth – bass guitars and drums won’t have extra thump beyond what’s in the recording. This can be great for genres like classical, acoustic, or jazz where a clean and uncolored presentation is desired (you’ll hear every detail and slight tonal difference). However, for bass-heavy genres such as EDM, hip-hop, or action movies/games, DF tuning might sound underwhelming or lacking in excitement due to the subdued bass. Many casual listeners also find the strong treble of some DF headphones to be tiring over long sessions.
  • Evolution and Usage: These days, free-field and diffuse-field targets are considered more of a technical reference than a preferred voicing for consumer products (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). Research (like Harman’s studies) showed that pure diffuse-field “neutral” was not what most people preferred in blind tests (Diffuse Field: Calculate, Characterize, Calibrate - Official Content - The HEADPHONE Community). As a result, newer headphones tend to incorporate more of a bass lift or other adjustments. Even so, the DF curve remains important: it’s an anchor for many measurement systems and “neutral” IEMs. In fact, Etymotic’s famous ER4 series was built on diffuse-field principles, and many seasoned audiophiles still regard that sound as the benchmark of neutrality. Some enthusiasts who find Harman tuning too bassy or warm will gravitate toward a diffuse-field-like sound for a “cleaner” presentation. One audio researcher noted that the Harman headphone target is not truly neutral (due to its bass boost), and if you want a more neutral sounding reference, the Etymotic/diffuse-field curve is closer to that ideal (The Etymotic Target (R.I.P. Harman) | Audio Science Review (ASR) Forum).
  • Summary: Diffuse field tuning represents the old-school idea of flat, reference sound. Expect a neutral midrange, less bass impact, and somewhat prominent highs, which can make music feel very precise but potentially lacking in warmth. It’s a great learning experience for your ears to hear music this way – you might pick up on details you never noticed before. Newcomers often describe the DF sound as “analytical” or “clinical.” It excels for critical listening and certain genres, but many people eventually prefer a bit more bass or a smoother treble for enjoyment. Think of diffuse field as the “textbook flat” sound – informative and uncolored, though not necessarily the most fun for everyday listening. It’s also a reminder that “flat” on a graph isn’t always what sounds best to our ears, which is why other targets like Harman came about.

Moondrop VDSF (Virtual Diffuse Sound Field) Tuning

  • Background: Some audio companies develop their own target curves blending science and their house sound philosophy. A well-known example is Moondrop’s VDSF tuning – VDSF stands for Virtual Diffuse Sound Field. Moondrop (a popular IEM manufacturer) created this target by taking inspiration from the diffuse field reference and the Harman curve, then tweaking to taste (Moondrop Blessing 2 – Page 2 – Twister6 Reviews). In other words, it’s a hybrid approach: Moondrop designers considered the neutral baseline of an Etymotic-like diffuse field, but added a bit of the warmth and balance from the Harman preference research. The result is their proprietary curve that they tune many of their earphones to. (Note: The term VDSF is often associated with Moondrop. Some other brands or enthusiasts might use similar concepts, but Moondrop popularized this specific naming.)
  • Sonic Characteristics: Moondrop’s VDSF tuning is generally regarded as natural, balanced, and easy to listen to. One review describes a VDSF-tuned IEM as having about a 3–4 dB bass “shelf” above flat, a clear but not overdone midrange with the “Harman-like” 3 kHz ear gain, and a well-extended treble that adds air and detail (Moondrop Blessing 2 – Page 2 – Twister6 Reviews). Compared to a strict Harman target, Moondrop’s interpretation often uses a slightly milder bass boost (so a bit less heavy in the low end) and sometimes a touch more sparkle up top. The goal is to avoid sounding either too bass-light (like pure diffuse field) or overly boomy. The mids are tuned to be clean and accurate – vocals and instruments sound correct in tone and placement. The treble is typically smooth but extended enough to convey detail and “space” in the music. Overall, VDSF yields a well-balanced, reference-like sound with a hint of musicality. Listeners often praise Moondrop IEMs for sounding very coherent and “right” tonally, neither boring nor fatiguing.
  • Listening Experience: Because VDSF is essentially aiming for an ideal middle ground, it works well across many genres. For example, Moondrop IEMs tuned this way (such as the Starfield, KATO, Blessing 2, Aria, etc.) are loved for their versatility. Vocals come through naturally (great for singer-songwriter, opera, podcasts). Rock and pop have enough bass to be engaging while keeping guitars and vocals upfront. Electronic and hip-hop might feel slightly less bass-heavy than on a Harman-tuned set, but still have satisfying punch unless you’re a serious basshead. Meanwhile, the good treble extension means classical and jazz also benefit – you can hear the texture of strings or cymbals clearly. Moondrop’s tuning tends to avoid extremes, so you won’t get exaggerated boom or sizzle; instead you get a sound that’s detailed yet relaxing and musical. Many newcomers find this type of sound signature very agreeable because it doesn’t over-emphasize any part of the spectrum.
  • Comparison: VDSF can be seen as Moondrop’s take on neutrality, differing slightly from the official Harman or diffuse field targets. For instance, where a pure Harman IEM might boost the bass ~9–10 dB, Moondrop might only boost ~3–5 dB to keep bass tight. Where diffuse field might have no bass boost and quite bright treble, Moondrop adds some low-end and keeps treble more controlled. The designers themselves cite it as combining Etymotic’s diffuse field reference with Harman’s curve (Moondrop Blessing 2 – Page 2 – Twister6 Reviews). In practice, this means VDSF sounds a bit more lively and full than old diffuse-field reference, but a bit more neutral and airy compared to Harman’s richer balance. It’s an example of how companies tweak scientific targets to match their vision of an ideal sound.
  • Summary: Moondrop VDSF is a popular modern target that exemplifies a balanced audiophile tuning. It delivers a reference-like clarity with a touch of warmth and sparkle. For a newcomer, if you try an IEM with this tuning, you might not even think about the curve – you’ll likely just notice that music sounds “correct” and enjoyable. It’s a nice demonstration of how blending targets (DF + Harman) can yield a very pleasant result. Other manufacturers have similar house targets (sometimes undisclosed), so you’ll encounter IEMs or headphones that are tuned to a specific ideal defined by their makers. VDSF just happens to be well-documented and talked about. If you see a product advertisement saying “tuned to our target curve for optimal sound”, that’s the same idea – a predetermined frequency balance that they believe offers the best listening experience.

Other Notable Professional Target Curves

Beyond Harman, Diffuse Field, and specific brands like Moondrop, there are a few other scientifically or professionally developed targets worth knowing:

  • Etymotic Target: Etymotic Research, an early pioneer in canal earphones, developed their own target response for the ER4 series of IEMs. This target is essentially a Diffuse Field reference (Etymotic aimed for the earphone to have the frequency response of flat speakers in a diffuse room at the eardrum). Many people refer to this as the Etymotic curve, and it’s very close to the diffuse-field standard discussed above. It is known for its perceived neutrality and is still beloved by those who want an uncolored sound. Some listeners like to add a small sub-bass boost to the Etymotic/DF target to suit modern music preferences (SoundStage! Solo | SoundStageSolo.com - Are There Valid Objections to the Harman Curve?) (since DF has minimal deep bass), but otherwise it’s a benchmark for flat sound.

  • Knowles Preferred Response Curve: In recent years, Knowles (a major manufacturer of drivers for earphones) published a target curve based on new research. It’s essentially an update to the Harman IEM curve using newer measurement techniques. The original Harman work used a measurement rig accurate up to about 8 kHz. Knowles, using a modern high-resolution simulator (the Gras 5128 dummy head, etc.), found that listeners preferred a bit more treble energy above ~3–4 kHz than the old rigs would suggest (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). The Knowles curve thus follows the Harman shape in bass and mids but adds some elevation in the upper treble (beyond 10 kHz) to ensure the sound is sufficiently airy on newer measurement systems (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). In simple terms, it’s Harman plus a sprinkle of extra high treble. This can translate to a slightly brighter, more “sparkly” sound on top, aiming to preserve details that older targets might under-represent. It’s a subtle tweak, but important in pro contexts; as measurement technology improves, targets are being refined.

  • Free Field Target: Historically, before diffuse field became the norm, free-field equalization was used. This was based on a flat speaker in an anechoic chamber (no reflections at all). A headphone tuned to free-field tries to match that scenario (What is diffuse field equalization | Headphone Reviews and Discussion - Head-Fi.org). In practice, free-field targets yielded a different frequency shape – often sounding mid-forward with less room gain compensation. It tended to cause localization issues (things sounding like they’re in your head) and was largely replaced by diffuse-field in the 80s (What is diffuse field equalization | Headphone Reviews and Discussion - Head-Fi.org). Almost no modern products explicitly use a free-field target, but it’s good to know as part of history. If diffuse field was “flat in a reverberant room,” free-field was “flat in an echo-free room.” Free-field headphones often sounded even brighter or more mid-peaky and were deemed unnatural, which is why they fell out of favor (What is Harman Curve? - HeadphonesAddict).

  • Studio Reference / Sonarworks Target: For professionals mixing audio, the goal is often to make any headphone sound like a perfectly flat set of studio monitor speakers. Companies like Sonarworks have developed calibration curves (e.g., SoundID Reference) to achieve this. Sonarworks’ target curve proposes matching a headphone’s response to a calibrated speaker system in a well-designed studio control room (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). This is similar in spirit to Harman (which was based on good home room speakers) but pushes towards even more accuracy: they measure many headphones and then EQ them to a reference curve, confirmed by listening panels against real speakers (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). The result of a Sonarworks calibration is usually a very flat response intended for mixing neutrality – essentially no coloration at all, so the mixer can hear exactly what’s in the track. For an audiophile listener, this kind of target might sound quite flat and maybe a touch dry (since it’s purely a tool to correct the sound). Still, it’s a professionally developed reference that underscores the idea of an absolute neutral playback in a pro environment.

  • SoundGuys and Other Site-Specific Targets: Audio review websites sometimes come up with their own “house” target based on their testing experience. For example, SoundGuys.com uses a preference curve that is an average of responses the reviewers liked, adjusted to their measurement gear. It ended up being similar to Harman but with less bass and treble energy (and thus relatively more midrange) (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). This means their target is a bit more mid-focused or “flat” to their ears, perhaps because they found Harman’s bass/treble a tad much. Similarly, RTINGS.com (another review site) initially adopted the Harman target for headphones but made minor modifications over time. These targets are less universally known, but if you see a review saying “we use our custom target curve to evaluate headphones,” it’s usually along these lines – often a slight variation of the Harman or diffuse field baseline to match that team’s preference or equipment.

Each of these professional targets has a rationale behind it, but all aim for some version of balanced sound. Small differences in these curves can lead to noticeable changes in listening (for instance, a few dB more treble can make music feel more open but also can highlight sibilance, while a few dB less bass can make something sound tighter but less fun). As you explore measurements, you’ll see these targets drawn on graphs as reference lines.

Community and Enthusiast-Developed Tunings

Apart from official research, the audiophile community has created its own target tunings and naming conventions. Enthusiasts often experiment and develop what they believe is the “ideal” sound based on experience, then share those targets with others. Here are a few notable ones:

Crinacle’s IEF Neutral Target (In-Ear Fidelity)

  • Background: Crinacle (a prominent IEM reviewer from In-Ear Fidelity) has measured hundreds of IEMs and developed a personal reference curve known as the IEF Neutral Target. This is an enthusiast-defined target – essentially, Crinacle drew a target curve that to his ears represents “perceptually neutral” sound (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). It’s informed by both the data (his huge measurement database) and his listening preferences. He initially published an IEF Neutral 2020 target (based on older IEC711 coupler measurements) and has since updated it (IEF 2023) to align with newer measurement standards (Bruel & Kjaer 5128 rig), ensuring it remains relevant.
  • Sonic Characteristics: The IEF Neutral tuning is intended to be very balanced, without the excesses or quirks that some find in Harman or other targets. In concrete terms, compared to the Harman IEM curve, the IEF target tends to have:
  • Listening Experience: Gear tuned to IEF Neutral (or EQ’d to it) often appeals to those who found the Harman curve’s bass too much or its mids too forward, yet still want a natural sound. It can come across as refined and agreeable – bass is sufficient but always tight, mids are natural, and highs are detailed without edginess. This tuning works well for all-round listening: it won’t exaggerate any genre, but everything from rock to classical will sound “correct.” Some might find it a tad polite for bass-heavy music (if they expect deep rumble, they might add a few dB of bass shelf), but others find it hits a sweet spot. As one user noted, the IEF target “nails my listening preference unlike any other” especially if Harman’s upper mids were too much for them ([Parametric EQ] AutoEQ database with IEF neutral target presets | Audio Science Review (ASR) Forum). It’s basically aimed at listeners who want true neutrality as they hear it – it might not wow you with excess bass or sparkly highs, but over time you might appreciate how nothing sticks out or offends.
  • Community Influence: Crinacle’s target is widely referenced in the headphone/IEM community. DIY equalizers and AutoEQ profiles have presets for IEF Neutral now, so others can easily try it out ([Parametric EQ] AutoEQ database with IEF neutral target presets | Audio Science Review (ASR) Forum). It’s a great example of how an individual’s accumulated experience can create a target that many others end up enjoying. It also highlights the differences from the big corporate target: for instance, many enthusiasts compare IEF vs Harman and discuss which they prefer. Neither is “right” or “wrong” – Harman was an average of many people, IEF is tuned by one very experienced listener (with input from data). If you find yourself agreeing with a particular reviewer’s taste often, you might like their personal target more than the general Harman curve. Crinacle’s target has become one of the best-known community curves, to the point that even discussions on forums consider it alongside the official ones (The Shape of IEMs To Come - Official Content - The HEADPHONE Community).

Other Enthusiast and Niche Tunings

  • Sound Signature Profiles (V-Shaped, Warm, Bright, etc.): Not all community “tunings” are formal curves; often they’re descriptive. Newcomers will hear terms like “V-shaped” which means a tuning with elevated Bass and Treble but recessed Mids (shaped roughly like a “V” on a frequency graph). This isn’t tied to a specific target curve paper, but it’s a very popular sound especially in mainstream consumer headphones. A V-shaped tuning gives powerful bass and sparkling highs, which can be exciting for rock, EDM, and pop (bass drops hit hard, and cymbals and vocals have shine), but you lose some mid detail (vocals/instruments might be pushed back a bit). Many bass-heavy headphones or early audiophile IEMs had this profile. Some community members actually prefer a mild V-shape for fun listening even if it’s not “neutral” by any target. Conversely, “warm” or “Harman-like” might be used to describe a tuning with boosted low end and smooth treble (Harman falls here), and “bright” or “DF-neutral” might describe a lean bass, high-mid/treble-emphasized tuning (like diffuse field). These terms aren’t specific curves but are part of the vocabulary that categorizes tuning in subjective terms. It’s good to understand them because a lot of enthusiast discussion will say things like “Headphone X is Harman tuned” or “IEM Y is a DF neutral set with a sub-bass boost” – meaning they took a diffuse-field style and just added bass.
  • Reviewer/Community Reference Headphones: Sometimes instead of drawing a curve, enthusiasts just cite a particular well-regarded headphone as a reference tuning. For instance, the Sennheiser HD600/650 are often mentioned as a gold standard for a balanced, natural sound (those have a mildly warm, mid-focused tuning). Someone might say “my target is basically the HD600 sound”. Similarly, some experienced listeners have a mental target that might be a blend of multiple references. These aren’t codified curves you can find published, but they influence how people talk about tunings.
  • Custom EQ Targets: Individuals often create their own EQ presets to achieve their perfect sound. If a custom EQ profile becomes popular, it sometimes gains a name (for example, an enthusiast on a forum might share a parametric EQ setting called “XYZ target” if others adopt it). While these are highly subjective and varied, it reinforces that every person can effectively have their own “target” once they dial in what they like. For instance, one person might decide their ideal is “diffuse field with +5 dB bass boost” and use that as their personal target curve for all headphones (and indeed, many find adding a bass shelf to DF is a great combo). Another might like “Harman but with the 3 kHz peak reduced a bit” as their target. These are endless in variety. The key is that community tuning philosophy encourages experimenting and tailoring the sound to your preference, not just accepting a single curve as gospel.

How Tuning Affects Music and Personal Preference

Sonic Impact and Genres: The choice of tuning can significantly affect your listening experience:

  • A bass-rich tuning (like Harman or beyond) will make rhythmic, beat-driven music (EDM, hip-hop, pop) very engaging. The impact and weight of bass notes are more pronounced, which can be fun and toe-tapping. However, the same bass-heavy tuning might muddy up classical or acoustic jazz where too much bass can overshadow delicate details.
  • A mid-forward or flat-mid tuning (like diffuse field or some studio targets) will make vocals and instrumentals crystal clear and lifelike. This is great for vocals, acoustic, classical, and folk – genres where you want the midrange to shine. But on the flip side, if the bass is too flat, you might find electronic or cinematic music lacking drama, and if the treble is very flat, you might feel things sound a bit dull.
  • A treble-tilted or bright tuning brings out hi-hat cymbals, string overtones, and tiny details, which can make complex music (like large orchestras or metal with lots of cymbal work) more resolving. Yet, push treble too high and it becomes fatiguing or sibilant, especially on poorly recorded tracks. Some diffuse field headphones were criticized for this reason – they revealed a lot, including harshness in recordings.
  • Balanced tunings (like Harman, VDSF, IEF Neutral) try to walk the line so that no genre is unlistenable. They won’t emphasize any one aspect extremely, which means they perform “pretty good” across all music. Many audiophiles gravitate toward these for daily use, then maybe use EQ or different headphones for specific needs (e.g., a bass-heavy set for the gym, a DF-neutral set for mixing a track, etc.).

It’s important to note that these impacts aren’t absolute – you can listen to any genre on any tuning, but your subjective enjoyment might change. For example, a basshead might find classical boring on a bass-light neutral headphone, whereas a neutrality seeker might find hip-hop on a bass-boosted headphone to be bloated. Part of the hobby is finding which tuning lets your favorite music shine.

Subjectivity and Evolving Preferences: Tuning preferences are incredibly personal and can change over time:

  • No Single “Correct” Curve: Audio experts and standards bodies have tried to define neutral targets, but even they acknowledge that there is no single correct FR that pleases everyone. One veteran put it succinctly: “In short, there is no single right way to do things and different people will find different equalisation 'natural' to them.” (What is diffuse field equalization | Headphone Reviews and Discussion - Head-Fi.org). Our ears and brains interpret sound uniquely. The Harman curve, for instance, is an evidence-based average preference – a great starting point – but it doesn’t invalidate someone who loves an HD650’s sound or an Etymotic’s sound more. The existence of multiple targets is itself proof that neutrality can be defined in different ways, and preference is king.
  • Human Factors: Several factors make tuning preference subjective:
    • Ear anatomy and HRTF: Each person’s ear shape (outer ear, ear canal resonances) affects how we perceive frequency balance. A target that sounds smooth to one person might sound a bit off to another because their ear boosts or cuts certain frequencies differently. For example, you might naturally have a sensitivity at 3 kHz; if a headphone follows Harman (which has a peak there), you could find it piercing while someone else finds it fine.
    • Hearing ability: Age and hearing health play a role. Older listeners often lose some high-frequency sensitivity, so they might prefer a brighter or more detailed tuning to compensate – or conversely, they might dislike excessive treble because it causes discomfort. Younger listeners might hear high treble very sharply and not need as much of it. This was observed even in Harman’s research – younger males leaned toward more bass, while some older listeners and females preferred a bit less bass (What is Harman Curve? - HeadphonesAddict).
    • Music taste and use-case: If you mostly listen to bass-heavy electronic music, you might gravitate towards a target with an ample low-end. If you mainly listen to acoustic and vocal-centric music, you might value midrange neutrality and find too much bass distracting. Headphone use cases matter too – for quiet home listening you might enjoy a neutral sound, but in noisy environments (commuting, etc.) a bass boost can help mask outside noise and keep the music exciting.
    • Psychological and cultural factors: Some people simply get used to a certain sound as “correct.” If you grew up with a particular headphone or speaker sound signature, your personal “neutral” might be biased by that. Also, initial impressions can be deceiving – a bright or bassy headphone might wow you at first, but you could tire of it, whereas a neutral one might seem underwhelming until your ears adjust and then you come to love its balance.
  • Evolution of Taste: It’s very common in this hobby for preferences to evolve over time. As you try more gear, your frame of reference expands. You might start as a bass enthusiast (many do, because bass is an immediately fun element), then gradually seek more clarity and transition to a neutral-ish preference. Or the opposite: someone might start with a studio-neutral headphone, find it boring, and realize they actually love a warmer, bass-rich sound for enjoyment. Neither path is wrong. Many audiophiles go through phases — for example, “I used to love big V-shaped sound, but now I find a smooth mid-centric tuning more satisfying for long listening.”
  • Adapting and Learning: Our hearing can adapt to a headphone’s sound after extended listening (sometimes called “brain burn-in”). What sounded strange initially can become the new normal after a few days of listening, and then switching back to another tuning might make that one sound odd. This is why it’s good not to jump to conclusions in the first five minutes of listening to a new headphone. It’s also why exposure to multiple tunings can help you refine what you truly like. You may discover you enjoy aspects of different targets for different reasons.
  • Use of EQ: As you get more comfortable, you might experiment with EQ (equalization) to tweak the sound. EQ allows you to effectively create your own target curve. If you find you always bump the bass up a bit on a neutral headphone, that tells you something about your target preference. There are tools and databases (like AutoEQ) where people share EQ profiles to match various targets (Harman, IEF, etc.), so you can even sample what those targets sound like on your current headphone and see what you prefer.

Bottom Line: Tuning is a subjective art as much as a science. Targets like Harman, Diffuse Field, VDSF, etc., are helpful reference points and give us a language to discuss sound. They explain why one headphone might sound warmer or brighter than another. However, they are not strict rules for enjoyment. Each listener’s “perfect” curve can be different. As one reviewer wisely noted, “Whether or not any of these target curves square with your own perceptions is something only you can judge.” (SoundStage! Solo | SoundStageSolo.com - Do We Really Need All These Target Curves?). In practice, many audiophiles use the Harman curve or similar as a useful neutral reference – it’s a reliable baseline where most well-tuned products cluster. But around that baseline, you’ll find endless variations that might suit you better.

For a newcomer, the best approach is: learn the general traits of these targets (as we’ve outlined), then listen for yourself. Over time, you’ll develop your own vocabulary (“I like a bit more sub-bass than Harman” or “I prefer a slightly laid-back treble, maybe between Harman and DF”) and you’ll know what others mean when they talk about these tunings. Remember, the ultimate goal is to enjoy the music. Whether you prefer the scientific Harman curve, the old-school diffuse field, an enthusiast’s custom tuning, or just a random headphone’s sound, the right tuning is the one that makes your music sound best to you. Happy listening!

References:

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