For audiophiles and everyday music lovers alike, choosing the right headphones can be a journey. Among the vast landscape of options, the Sennheiser HD 6XX and Hifiman Sundara frequently emerge as top contenders, especially when considering open-back designs. Many find themselves in a “Headphone Compare” dilemma, wondering which of these highly-regarded models deserves their investment. Having spent considerable time with both, this article dives deep into a detailed headphone compare experience to help you decide which headphone might be the perfect fit for your ears and listening preferences.
Disclaimer:
As someone relatively new to the world of high-fidelity audio, my perspective is shaped by personal listening experiences and comparisons within my limited gear collection. My opinions are subjective, and your own experiences may vary. Auditory perception is unique, and what sounds exceptional to me might be different for you.
For this headphone compare, both the Sennheiser HD 6XX and Hifiman Sundara were primarily tested using the following setup:
- DAC: JDS Labs DAC+
- Amplifier: Rebel Audio RebelAmp
- Music Source: Qobuz via Roon
I also experimented with the Sundara using the Zen Can and Atom Amp. While the Atom Amp occasionally introduced a touch of harshness in the treble on certain tracks, the warmer profiles of the Zen Can and RebelAmp effectively mitigated this, with the RebelAmp delivering superior overall sound quality, as expected given its price point.
It’s widely known that the HD 6XX, in particular, can exhibit varying sonic characteristics depending on the amplifier used. My current testing is limited to the mentioned setup, so keep in mind that results might differ with alternative DACs and amplifiers. This headphone compare is based on my experiences with the specified equipment.
Background: The Quest for Comfort and Sound
Having enjoyed the Hifiman Sundara for a while, my search for another headphone stemmed primarily from a desire for enhanced comfort. While I deeply appreciate the Sundara’s sonic capabilities, their weight became a noticeable factor during extended daily use while working from home.
The Sundara’s design also seemed to exert pressure on a sensitive point where my jaw connects to my skull. Despite attempts to adjust the headband, this pressure remained, particularly during longer listening sessions.
To alleviate this, I alternated the Sundaras with modified Koss KSC75s, equipped with a headband and Yaxi pads. The KSC75s are incredibly lightweight, feeling almost weightless. They deliver remarkable sound for their price and are suitable for tasks like Zoom meetings, but I sought a headphone offering superior audio quality for immersive, long-term listening.
Sennheiser, renowned for crafting some of the lightest yet highly-regarded audiophile headphones, naturally became a focal point. It’s surprising how often the weight of audiophile headphones, often exceeding 350 grams, is overlooked in reviews. Often, this heft is attributed to the use of metal for perceived durability and a “premium” feel, rather than contributing to driver performance. While the Sundara’s metal components look aesthetically pleasing, I personally prioritize lightweight plastic for comfort over heavy “premium” metal in headphones designed for extended wear.
Admittedly, I initially harbored some reservations about Sennheiser due to encountering overly enthusiastic (and sometimes dismissive) fans in online audio communities. However, I realized that personal preferences should not be dictated by others’ opinions. Exploring Sennheiser’s lineup, the HD 6XX emerged as an appealing option, balancing affordability with a reputation for a warm and relaxing sound signature.
Comfort Comparison: HD 6XX and Sundara – A Tale of Two Headbands
My comfort concerns with the Sundara have been previously detailed. Now, let’s delve into the comfort aspects of the HD 6XX in this headphone compare.
The primary comfort drawback of the stock Sennheiser HD 6XX is the firmness of its earpads, especially compared to the plush Sundara pads. While I believe I could acclimate to the earpads around my ears, the original headband padding was simply too rigid. To address this, I replaced the stock headband pad with Dekoni Nuggets. This modification significantly improved the comfort, eliminating the sensation of pressure points on the top of my head. While this might potentially create new pressure areas over time, the overall comfort improvement was well worth it for me.
Regarding the earpads, given their expected lifespan of about a year, I plan to explore Dekoni replacements when the time comes, to assess if they offer enhanced comfort. I am aware that pad changes can subtly alter sound characteristics, but comfort remains a higher priority for me than absolute tonal purity.
Sennheiser headphones are known for their substantial clamp force, and the HD 6XX is no exception. However, by following online guides for gently adjusting the metal bands, I was able to achieve a comfortable fit. Crucially, the HD 6XX’s lightweight design lived up to my expectations, completely eliminating the jaw pressure I experienced with the Sundara. Overall, I am very satisfied with the HD 6XX’s comfort after these adjustments.
Sound Quality Face-Off: HD 6XX vs. Sundara – Unveiling Sonic Personalities
The experience of alternating between the Sundara and HD 6XX proved to be a captivating exploration of their distinct sonic signatures. This headphone compare truly highlights how differently these two excellent headphones present audio.
The “Sennheiser veil,” often debated and sometimes dismissed as nonexistent, was immediately apparent. Switching to the Sundara from the HD 6XX reveals a significant increase in treble presence. Cymbals, high-pitched synthesizers, and strings gain a vibrancy and detail on the Sundara that is noticeably subdued on the HD 6XX. Perhaps this effect is less pronounced on the HD 600, or perhaps the Sundara leans towards a brighter sound profile. (Having briefly tested the Beyerdynamic DT 1990 Pro in a store, I can confidently say that the Sundara’s treble is far from being overly aggressive compared to those, which I found uncomfortably bright.)
However, as previously noted when using the more neutral Atom Amp, the Sundara’s treble can occasionally become harsh, particularly with distorted drums and synthesizers. Tracks like “Time to Pretend” by MGMT, with its persistent distorted synth line, could become almost fatiguing. The warmer character of the RebelAmp provided welcome relief, smoothing and enriching these sounds, making them more enjoyable. I anticipate this wouldn’t be an issue with the inherently warmer HD 6XX. Nevertheless, the HD 6XX pairs harmoniously with the RebelAmp’s warmth and richness.
Headphone Compare: Sennheiser HD 6XX versus Hifiman Sundara. Side-by-side view of open-back audiophile headphones.
I discovered an EQ profile for the HD 6XX on Head-Fi that I find enhances its sound by adding some extra treble and sub-bass:
6xx EQ profile:Conversely, Amir from ASR’s EQ settings for the Sundara, in my experience, diminished its characteristic sparkle, so I discontinued using it. Perhaps other EQ profiles might be worth exploring, but I am generally content with the Sundara’s stock sound signature.
The HD 6XX exhibited a wider soundstage than anticipated, contradicting some reviews, but it still falls short of the expansive soundstage of the Sundara. The Sundara envelops you in sound, creating a sense of immersion. It also boasts superior clarity and airiness, allowing for easier instrument separation and detail retrieval compared to the HD 6XX.
One area where the HD 6XX truly excels is in “punch and slam.” Tracks with driving rhythms are incredibly engaging and impactful on the HD 6XX. The praised midrange tonality of the HD 6XX is also evident, rendering vocals with exceptional richness and presence. This is particularly noticeable in vocal-centric songs, like Joni Mitchell’s “Both Sides, Now,” which gains a fullness on the Sennheisers that is less pronounced on the Hifiman. The HD 6XX’s punch and midrange prowess can sometimes make the Sundara feel comparatively less dynamic. While cymbals and strings possess more distinct character on the Sundara, bass instruments gain prominence and definition on the HD 6XX.
However, the HD 6XX’s punch can occasionally be overwhelming. The strong kick drum in delicate folk songs like Simon and Garfunkel’s “The Boxer,” for instance, can feel somewhat out of place. I encountered a similar issue with “Cruel” by St. Vincent, where the kick drum became overpowering. These songs, conversely, sound beautifully balanced on the Sundara.
Many rock albums, however, such as Elbow’s Little Fictions, sounded distinctly more vibrant and engaging on the HD 6XX, while the Sundara felt slightly subdued. Similarly, Hedersleben’s The Fall of Chronopolis transformed from a somewhat bland listen on the Sundara to an exhilarating experience on the HD 6XX, almost as if the headphones unlocked a new dimension in the album.
Moving to heavier genres, Tool’s “AEnema” truly highlights the HD 6XX’s power and authority. The track almost sounds like two different recordings on each headphone. On the Sundara, the toms are beautifully spacious and detailed, but the overall presentation feels somewhat detached. The HD 6XX, in contrast, delivers a visceral, head-nodding impact.
Mellow jazz pieces like Miles Davis’ “So What” fared better on the Sundara, creating a convincing sense of being in the room with the musicians. I also found The Cure’s “Plainsong,” with its sweeping grandeur, more enjoyable on the Sundara – the HD 6XX made it sound slightly muddied and homogenous. Arcade Fire’s “Reflektor” sounded better on the HD 6XX, but “Joan of Arc” from the same album was more engaging on the Sundara. (Interestingly, the first minute of “Joan of Arc” was preferable on the HD 6XX, but as strings, synths, and backing vocals entered, the Sundara’s enhanced treble became advantageous. Ultimately, I could happily listen to the entire song on either headphone.)
For tracks relying on a driving rhythm, like Pink Floyd’s “Dogs” and Fleetwood Mac’s “The Chain,” the HD 6XX proved more compelling and energetic.
Surprisingly, a Grateful Dead album (Blues for Allah) resonated more with me on the HD 6XX, while a Jethro Tull album (Thick as a Brick) was more enjoyable on the Sundara. Jazz and orchestral/classical soundtracks generally favored the Sundara, but solo instrument classical pieces, like piano sonatas, were more captivating on the HD 6XX, where the tonal richness takes center stage and soundstage becomes less crucial.
The HD 6XX also appears to be more forgiving of less-than-ideal mastering quality, whereas the Sundara’s clarity reveals all aspects, both positive and negative, of a recording.
Conclusion: A Complementary Duo
At its least impressive, the Sundara could sound somewhat flat and uninspired compared to the HD 6XX. Conversely, at its least impressive, the HD 6XX could sound muffled and confined in comparison to the Sundara’s openness. This varied not only based on genre, artist, mastering, and specific track, but also sometimes simply on my personal mood, underscoring the subjective and nuanced nature of audio preference. At their best, with the right music and mindset, both headphones are capable of delivering breathtaking and deeply moving sonic experiences.
It becomes clear why many audiophiles consider the HD 6XX and Sundara as complementary headphones. They each accentuate different facets of the music. It can even be challenging when listening to a track and realizing certain elements would shine more on one headphone while others would benefit from the other’s strengths. Naturally, this sparks a desire for a headphone that combines the HD 6XX’s punch and midrange with the Sundara’s soundstage, treble extension, and clarity. However, achieving such a combination likely requires a significant price increase, potentially venturing into the realm of headphones like the Susvara or HD 800 S, which are beyond my current budget.
Ultimately, while I will continue to utilize the Sundara for specific musical selections and for variety, the HD 6XX is likely to become my primary daily driver due to its exceptional comfort and lightweight design – a feature often understated in headphone reviews. The availability of high-performing headphones weighing around 260 grams should be more prevalent in the audiophile market.
