Drop + Grell OAE1 Signature Headphones

Introduction

The Drop + Grell OAE1 is an open-back headphone designed by Axel Grell, famed for his work on products like the Sennheiser HD600 and HD800 series. As a result, there was a lot of chatter and expectations about these headphones and what they would sound like. I've had enough time with them to form some solid thoughts, so I'd like to share those with you guys today. As usual, I'll talk about the build, the sound, and some comparisons to other headphones.

For full transparency, I was provided a review unit by Drop in exchange for my honest thoughts. I will note that at least with my experience, Drop was very proactive in trying to maintain the integrity of the review, being very clear that they had no requests regarding the content aside from posting the review on the Drop platform as well. So kudos to them regarding that.

For reference, this model was priced at 299USD but has since gone as low as 199 USD, putting it squarely against competitors like the Hifiman Edition XS and the Sennheiser HD6XX.

Now onto the review!


Build and Accessories

The OAE1 comes in what I'd consider pretty standard Massdrop packaging. It's just a cardboard box with the barebones inside. Headphones, cable, connection adapter, and an instruction manual.

The yokes and mesh are made of metal and have a nice solid feel to them. They don't feel flimsy at all and there’s a sense of refinement with how everything’s put together. Measuring 375g on my scale, they don't feel very heavy on the head and I wouldn't mind wearing them for hours (if it wasn't for other issues detailed below).

The cups can fold to lie flat (though can't do a full 180), which gives them a good amount of swivel to fit different heads. The adjustment mechanism feels pretty smooth, though I wish there were tactile steps or marks. The velour on the earpads are a bit scratchy and feel similar to cheaper aftermarket pads. But the foam is not overly squishy or stiff and the ear holes are decently sized.

The earpads use proprietary clips to mount onto the cups and it’s hard to even tell that they’re removable at first because of how flush they are. It’s not as cumbersome to attach as Hifiman’s mounting mechanism, but is still kind of a pain to work with. I'd also be very careful about trying to pry the earpads by pulling from the inside, the fabric of the earpad tears very easily from the bottom.

The headband is just okay. The padding is minimal and I do worry about the longevity of the pleather. It just feels like the kind of pleather that's bound to flake off over time (though supposedly all parts on this headphone are replaceable).

The cable is single-ended, wrapped in fabric, and feels decent. I actually like this cable since it’s pliable enough that it’s easy to untangle despite having a bit of memory to it. I like that you can connect it to either earcup, so you can have the cable on the left or the right. It’s a little weird at first because the cable fits in "seamlessly" to the connector, so you have to push it in more than you expect. But like the earpads, it means everything's flush and clean once you have it connected.

Comfort-wise, this is where things fall apart for me. The first issue is that the headband adjustment does not extend much. I have a larger head but I haven't come across something that didn't fit until the Grell OAE1. Even with the headband fully maxed out, it feels like I'm one notch below my preference.

The second issue is that the clamp force feels incredibly high. I do like a firm clamp, especially with smoother earpads, because it keeps the headphones from slipping around. But these feel like they clamp harder than the HD600 series. I assume the tight fit on my head is part of the reason it feels particularly intense.

So for me, what ends up happening is basically a triangle of death where the sides and top of my head are all being crushed at once. I think it would be bearable for me if the headband could at least adjust a bit more, but in its current state, I get actual headaches from using the OAE1 for more than 30 minutes.

Power-wise, while these are only 38 ohms, I found they actually need a little more power than the HD6XX to drive. They’re similar to the AKG K700 series in that regard, which also needs more power than you would expect. While it can run off a dongle, I’d recommend using a dedicated headphone amp for best results.

Overall, I like the design and build of the Drop + Grell OAE1. It feels refined and deliberate with reasonable compromises in materials. But the comfort for me is a dealbreaker. I think this headphone could be fairly comfortable for smaller heads, but for people like me, it is just painful to use the OAE1 for any extended period.


Sound Impressions

So initially, I felt like the general sound of the OAE1 was like a dark version of Grado. It's bassy, very forward in the upper midrange, and seems to focus more on being lively than accurate. Having listened to it more, I still think the OAE1 has some Grado-like qualities, but it’s definitely its own beast. I'll be honest, even after spending almost a month with the OAE1, I'm still unsure how I feel about the sound.

Let's start with the OAE1's strengths. The main thing that people will notice is the bass. While I wouldn't say the resolution and texture punches above its price point, this is bass that I haven't heard from an open-back before. It is incredibly boosted, we're talking consumer-audio levels of bass here. It bleeds into the lower mids so it does make things a bit muddy. But to my ears, it also extends quite low into the subbass, so the bass response has a lot of weight and rumble behind it. The OAE1 is probably the closest you'll get to a bass shelf from an open-back aside from an EQ'd planar.

The other thing is the very forward upper midrange. Overall, this helps with retaining clarity as vocals and instruments still cut through despite the copious amounts of bass. Vocals can sound very up close, as if they're right on my head. The positioning of the headphones affects this and I find it's a bit too close and intense wearing normally. So I prefer to have the cups pushed more forward so that the drivers are further away.

Together, these qualities in the OAE1 make it easy to just get into the rhythm of the music and vibe with the beat. However, when I listen more carefully, there are some issues that drag the OAE1 down for me.

The biggest issue is what sounds like a huge treble dip somewhere in the 6-8khz region. Combined with the big bass boost, what this ends up doing is making the OAE1 sound very thick and heavy. The music sounds closed-in and claustrophobic, lacking room to breathe and spread out. While you can hear the main "body" of the sound clearly, the nuances are blunted and rounded off. It doesn’t feel like you get the full range of the sound. In addition, while the boosted upper midrange does help with retaining clarity, the treble dip works against it. So rather than sounding full and clear, the OAE1 can sound both shouty and strained.

This also means that the OAE1 doesn't sound particularly detailed. It’s almost like a photograph that's had the contrast boosted too much. It looks nice at a glance, but the texture and finer details are lost. I found this improves by removing the felt dampening material on the driver. This makes the sound less claustrophobic and removes some of the bass bloat. However, the downside is that the treble becomes quite bright and sharp. And more importantly, that dip seems to contribute to the OAE1's other unique trait.

Which is the soundstage presentation. Now, I think Drop's blurb about an "ultra-expansive" soundstage is somewhat misleading. For me, the soundstage on the OAE1 is pretty small, similar to the HD6XX. This means it suffers from the same issue as the HD6XX, which is that the separation isn't very good when things get busy and the music easily becomes a wall of sound.

That said, I find the imaging to be better on the OAE1. It feels more precise with horizontal imaging in particular and that means it can actually sound wider than the HD6XX, depending on the mix. It's also decent for gaming because of this (though I prefer it for cinematic gaming since the bass can be a bit too much for things like shooters).

But what's unique about the sound presentation is that the music actually seems to be projected forward. Usually for me, I hear soundstage like the front of my head is where the mic is and everything is playing more towards the back. But on the OAE1, I actually hear everything pushed up to the front of my head. While it's not enough to give me the illusion of speakers or anything, it is an interesting effect that I haven't gotten from any other headphones to this degree.

As I mentioned before, you can kind of fix some of the issues with the OAE1's stock tuning by doing some mods or using EQ. However, I found that whenever I did, this always made the OAE1 sound more like a "regular" headphone. The bass response remains surprisingly hefty, but you lose some of the subbass quantity. And while the soundstage still projects forwards, the effect is not quite as strong and the OAE1 just ends up sounding like a super shouty headphone.


Comparisons

So this time, I'll be doing comparisons a bit differently. I noticed that no matter what headphone I compared to, I pretty much had the same impression of the OAE1's strengths and weaknesses. So I'll be comparing multiple at once with the OAE1 and hopefully that'll give a better idea of what kind of headphone it is.

Now the OAE1's bass is really what I think will appeal to people more than the soundstage presentation. As I mentioned before, it's quite boosted and bleeds into the lower mids, giving you thicker and heavier bass than even something like the Sony WH-1000XM4. But if you EQ it down, it is decently textured and you still have shockingly good extension down to the subbass. To my ears, it definitely beats the Sennheiser HD6XX and it extends lower than even the Aune AR5000, which I thought had pretty good extension for an open-back. IMO, it's comparable to the kind of extension you get from Hifiman planars.

The other thing is that the bass has a respectable amount of slam and impact even after EQing it down. I haven't heard any other open-back in this price range with the OAE1's level of slam. The Edition XS and the HD6XX sound limp in comparison. I also find it slams harder than the Aune AR5000 or the Beyerdynamic DT880. It's not quite at the level of slam that the Fostex biodynamics have, but it's not far off from something like the Hifiman HE6se V2.

In terms of the treble, the OAE1 is not as bright as Hifiman or a Beyerdynamic. In fact, due to the treble dip, I’d say the treble is more on the inoffensive side. With the stock tonality, there’s no sense of sibilance or sharpness. I think people would probably even say it sounds veiled compared to the HD6XX. The upper midrange is boosted quite a bit though, so if you’re sensitive to shouty headphones, this might not be a good match.

As for its portrayal of timbre, I don't find it to be particularly special. In fact, the OAE1 sounds a bit "dry" to me, similar to the Fostex biodynamics or Beyerdynamic. The Aune AR5000 and the Sennheisers sound more natural and music flows together in a pleasing way. The blunted effect from the treble dip and the bass bloat also means you don't really get a lot of texture from sounds and instruments. That said, if you listen to other headphones after the OAE1, you’ll probably feel like you’re missing a lot of body and physicality in the sound.

In terms of soundstage size, the OAE1 seems just a little bit bigger than the HD6XX. The Aune AR5000, the Edition XS, Sundara, and Beyerdynamic all seem noticeably larger in soundstage. Part of the reason is likely because the OAE1's darker tonality makes it sound less airy and open. That said, I find the OAE1's imaging to be above average. Not quite as precise as the Edition XS or Beyerdynamic, but better than the HD6XX and AR5000 to my ears.

Now in terms of soundstage presentation, the closest is probably the AR5000, which is also another headphone with offset drivers. However, the effect of having sound projected "in front" of me is not as strong. With the AR5000, I feel like I'm always in-between the vocals and the instruments, with the vocals projected in front and instruments behind. Other headphones like the HD6XX sound like everything starts from the center of my head. But the OAE1 projects everything in front, including the instruments (though the vocals still end up being the standout). Note that this is relative to headphones though, I’m not getting anything like an out-of-head sound experience.

Resolution-wise, the OAE1 is okay, but not particularly competitive. The Edition XS, HD6XX, and Aune AR5000 are all more capable at pulling nuances out of the sound. However, I feel that the OAE1's tonality plays a large part. When you mod or use EQ, the resolution seems more appropriate to its price point. But listening stock makes the sounds seem more muted than you’d expect. Even a bassy headphone like the Sony WH-1000XM4 has a level of clarity and airiness that the OAE1 lacks.

In terms of build and comfort, I feel that the OAE1 is built quite well. I like the small attention to detail like making everything flush and the quality of the materials they use. It feels a bit more premium than a Beyerdynamic DT series. That said, even considering that my head is a bit too big for the OAE1, the clamp force is just incredibly strong and the headband doesn't really provide much support. So while I find it better built than a lot of its competitors, it’s the least comfortable headphone I’ve tried in this price bracket.


Conclusion

A headphone that comes to mind when I think about the OAE1 is the now discontinued Sony MDR-MA900. This headphone looked quite similar and was also very "open" in design, basically being just two drivers hanging around your ears. What was impressive about it was that the soundstage was almost like a mini-HD800; it was large, spacious, and seemed to fully encompass my head. It also had surprisingly good bass response for how open it was, achieving a similar level to other open backs even if you took off the pads.

Now based off the blurbs about the OAE1, that's the kind of headphone that I think a lot of people were expecting. But the OAE1 is something else entirely. It's a headphone that's grown on me because it does some things very differently like the sound presentation and the bass extension. And to be fair, once I get used to the OAE1’s sound, I’m actually inclined to call it an engaging headphone. But it's hard for me to really embrace the OAE1 because once you listen to pretty much any other headphone, the OAE1 sounds off and "wrong". I feel like to really enjoy the OAE1, you pretty much have to listen to it exclusively.

Supposedly the OAE1 may have alternative parts that'd help you tune the sound more to your preference in the future; I hope that really does come because I think that would do a lot to help people appreciate the unique traits of the OAE1's sound.

As it is now, it's not something I can really recommend to people as a blind buy. But I do feel like there are certain niches that would enjoy the OAE1. I think people who want a thicker sound and care more about the feeling they get from music rather than the intricacies would enjoy this headphone. It's basically the antithesis of the clean, detailed, and clarity-focused sound that's been popular in the hobby. The other niche is for those looking for that one unicorn headphone; an affordable open-back that has bass like a closed-back.

Axel Grell is a renowned audio engineer credited with the creation of some of the most esteemed headphones globally, including the Sennheiser HD600, HD650, and HD800. After many years of dedicated service at Sennheiser, Mr. Grell made the decision to establish his own brand, leading to the inception of Grell Audio.

To facilitate promotion and sales, Grell Audio formed a partnership with the community-oriented platform Drop. The inaugural product from Grell Audio was the Drop + Grell TWS/1, a wireless earphone set for which I had the honor of writing the world premiere review. Currently, Grell Audio has returned with a full-sized headphone, the Drop + Grell OAE1.



Drop + Grell OAE1

The Drop + Grell OAE1 is a full sized, open back headphone with a revolutionary driver geometry that promises to make them sound like speakers in front of the listeners head. The OAE1 positions the drivers further out and in front of the ears to create a soundfield that’s stunningly natural. It’s an innovative yet undeniably intuitive acoustic concept that Axel Grell first implemented in high-end Sennheiser headphones like the HD800 and now has tried to perfect it.

The two speaker membranes of the Grell OAE1 are positioned at an angle to the ear to project the sound waves as if they were coming from a source directly in front of the listener. The drivers are broadband transducers with bio-cellulose diaphragm.

The baffle also contributes to the unique listening experience that the OAE1 promises. The Grell OEA1 has an extremely large, curved and open baffle, which is complemented by an open ear cushion. This design allows the sound to spread naturally without being reflected by large closed areas. The high-precision stainless steel mesh guarantees high acoustic permeability and controlled bass reproduction. This prevents sound coloration and resonances.

Widening the soundstage even further, Axel Grell and his team developed ear-cups that are 90% open metal mesh and a woven stainless steel acoustic-damper mesh, both of which allow sound waves to pass through with minimal interference.

You can read the whole design concept of the Drop + Grell OAE1 here.



The signature edition

The Drop + Grell OAE1 initially debuted as the "Signature" model, a limited edition collector's item with only 1,000 units available, which quickly sold out within a matter of weeks.

This Signature model was priced at $349 and showcased silver-painted ear cups and hinges, each adorned with Axel Grell's engraved signature. Additionally, the headphones came with a premium carrying case and included two cables: one featuring a 3.5mm plug and the other a balanced 4.4mm plug.



The standard version

Grell Audio and Drop have joined forces to introduce the standard version of the OAE1, which shares the same tuning as the Signature model but incorporates a couple of notable modifications.

The most significant change is the reduction of clamping force, which has been adjusted to 3N from the 3.5N found in the Signature edition, resulting in less pressure on the head. While the Grell OAE1 still exerts a firmer grip than many headphones available on the market, it now offers improved comfort and less pressure on the head.

In terms of aesthetics, the standard OAE1 showcases a more understated black finish, favored by Drop, along with prominent L and R indicators within the ear-cups to assist with orientation and placement.

The standard Grell OAE1 is priced $50 lower; however, this reduction comes at the cost of the practical carrying case and the balanced cable. These accessories are quite beneficial, and I would willingly pay the additional $50 to obtain them. It would be advantageous if Drop provided two bundle options, allowing customers to make a choice.



Non Audio stuff

The OAE1 is constructed with high-quality materials and features a simple, minimalist aesthetic that is likely to attract a wide audience. The ear-cups consist primarily of a large metal mesh, complemented by a woven stainless steel acoustic damper mesh. Aside from the outer rings, which maintain a silver finish, the remainder of the design is coated in black.

The ear-cups are secured to the headband using aluminum clamps. The headband itself is rounded, padded with memory foam, and wrapped in PU leather. The central section of the headband incorporates lower density foam to prevent the formation of pressure points.

The velour ear pads are generously thick and filled with firm memory foam, ensuring that the drivers are positioned at an optimal distance from the listener's ears, which is crucial for the tuning process.

The mechanism for adjusting the headband operates smoothly and is sufficiently tight to maintain its setting. All components of the headphones are designed to be user-replaceable.

The circular ear pads are sufficiently wide and deep to fully encompass the ear while allowing for ventilation. However, the velour surface does not provide a cooling effect, and some perspiration may occur after extended use. The ear pads possess a firmer texture than usual, which may require an adjustment period. The ear cups feature a 180-degree swivel mechanism for enhanced positioning.

The headband offers adequate comfort, enabling prolonged use of the headphones for several hours without the necessity for breaks.

The Drop + Grell OAE1 is a lightweight headphone, weighing 375 grams. With a reduced clamping force, it delivers a comfortable fit comparable to that of most other headphones.

It is noteworthy that the headband adjustment mechanism does not extend significantly, even at its maximum setting, which may result in an inadequate fit for individuals with larger head sizes. Personally, I find the fit to be just barely adequate at the maximum adjustment. This concern was raised by the community regarding the Signature model; however, the headband design has not changed in the standard version.



The cable and accessories

The Grell OAE1 is designed to accommodate both dual and single entry cables, as each ear-cup is equipped with a socket that accepts a 2.5mm plug. An integrated overhead wire facilitates the sharing of the input signal between both drivers when utilizing a single entry cable, allowing for connection to either side. Additionally, the headphones can support both dual and single entry balanced cables.

Nevertheless, the input sockets feature an extended plastic tunnel that serves to protect the plug from unintentional bending; however, this design also restricts the diameter, making it challenging to locate aftermarket plugs that are compatible.

Given that the standard version of the Grell OAE1 is supplied with only one single-ended cable, finding a suitable balanced cable may prove difficult due to this diameter constraint. Therefore, it would be prudent for Drop and Grell Audio to consider offering the original balanced cable that was part of the Signature model bundle.

Except for the cable you only get a 6.35mm plug adapter.



Audio stuff

The headphone features a nominal impedance of 38Ω and a sensitivity of 106dB/Vrms, making it easy to drive without the requirement for specialized amplification. My primary usage has been with the FiiO M23, the iBasso DX180 and the Aune S9C Pro, utilizing the balanced cable from the Signature version.

The Grell OAE1 delivers an astonishing level of bass that may be difficult to comprehend upon initial listening. It requires a brief period to acclimate and fully grasp the auditory experience. The sub-bass extension is remarkable for an open-back headphone, particularly one at such an affordable price point. It is challenging to identify another open headphone that can reproduce frequencies as low as 20Hz with such fidelity. Axel Grell has achieved a tuning that simulates the sensation of having subwoofers positioned near the ears while maintaining impressive clarity in both the midrange and treble frequencies.

The bass is accentuated, deviating from a neutral response, which is unexpected given the designer's background with the HD800. However, this emphasis is not so pronounced as to reach excessive levels that would compromise tonal accuracy. While it is accurate to say that the Grell OAE1 does not offer the most tonally precise low-end, its exuberantly tuned bass creates an engaging and enjoyable listening experience. It is capable of handling classical and acoustic genres, provided one is willing to overlook its lack of neutrality and embrace its more relaxed character. Personally, it may not be my preferred choice for classical music, but it excels with a wide range of other genres, particularly modern electronic and trance music.

In terms of technical performance, the Grell OAE1 generally exceeds average standards. The bass is tight and well-controlled, free from noticeable echo or reverberation, while also being highly impactful and dynamic. It features rich textures and demonstrates quick response times, along with commendable definition and layering. However, it struggles with complex and dense bass lines, where it tends to become one-dimensional, slightly blurred, and somewhat bloated.



More Audio stuff

The Grell OAE1 excels in maintaining an impressive balance and presence in both the mid-range and treble, even with its pronounced low-end. The bass is well-defined, ensuring it does not overshadow or interfere with the mid-range, which is allowed to express itself with clarity and remarkable resolution for its category. The overall tuning is notably balanced, providing satisfactory tonal precision and a natural timbre. The OAE1 is both musical and engaging, offering a rich harmonic variety that connects the listener to the music, effectively reproducing both vocal and instrumental performances.

The mid-range stands out as the headphone's most compelling feature, and in my opinion, it presents a more appealing and balanced sound than the renowned Sennheiser HD650, despite its emphasis on the upper mid-range. Axel Grell appears to have achieved a more refined and sophisticated tuning with the OAE1, resulting in a sound that feels more lifelike and realistic, while minimizing listener fatigue.

The treble is bright and lively, serving to balance the pronounced low-end and prevent an overly warm or dark sound profile. It possesses a brightness that is neither harsh nor piercing, and it resolves adequately for its category, though it may not be perceived as particularly spectacular or brilliant. The Grell OAE1 can be somewhat unforgiving with lower-quality recordings, particularly when paired with bright sources.

A notable drawback regarding the treble is its occasionally unnatural and metallic timbre, which can sound somewhat artificial at times. There is a degree of sterility and dryness, coupled with mildly suppressed overtones and a relative lack of harmonic richness. However, the perceived effects can vary significantly depending on the music and recording quality; for instance, classical music may not be as satisfying, while listeners of electronic music may find little to complain about.

The soundstage

The soundstage presents a varied experience, as it does not create the impression of the OAE1 resembling speakers positioned in front of the listener, contrary to its claims. It does not exhibit a greater expansiveness or holographic quality than most headphones and is notably less wide and immersive than the Sennheiser HD800. Nevertheless, it successfully delivers impressive spatiality with a pronounced central image that appears to emanate from a location outside the listener's head. While the Grell OAE1 may not provide extraordinary expansiveness, it offers a remarkably spacious and open sound within its confines, boasting class-leading depth layering and positioning, even when compared to significantly pricier headphones.



Conclusion

The Drop + Grell OAE1 represents a scientific endeavor by a renowned acoustic engineer, resulting in a headphone that, while very good, may not cater to all preferences. It may not excel in rigorous critical listening and does not fully deliver on its promised speaker-like attributes. However, it does provide an unprecedented sense of spatiality and features a deep bass response that is emphasized yet maintains a balanced overall tuning.

The bass performance is impressive for an open-back headphone, and the tuning approach is vibrant and enjoyable, making it particularly well-suited for casual listening without sacrificing sound quality. The newly released standard version has improved upon the comfort issues found in the Signature model and is offered at a more accessible price point. While the Drop + Grell OAE1 may not resonate with everyone, it is likely to cultivate a dedicated following among enthusiasts.

The review sample was kindly provided free of charge in exchange for an honest review. I don't use affiliate links. The price of the Grell OAE1 is $299 and is exclusively available from Drop. You take advantage of the pre-order discount and get them for $249.

Disclaimer: For various Google indexing reasons, parts of this review may have been processed with an automatic paragraph rewriting tool. However it reads exactly the same as the original content that is available in my website.

My unit arrived. Listened today for a few hours and listening as I am writing. I may not be able to point to every point but will write things that stood out to me so far.
Ran on Topping G5.


Comfort.

Even the HE-1 would be useless if it were not comfortable. I understand it can be very comfortable for smaller heads but it is not for those with big or say long heads. I am 6 feet 2 inches, I do not have a wide head but moderately tall one. Even at its max size it puts pressure on the center of the head. Unlike the Sennheiser phones which try to put pressure on two points. I got pretty angry with such a flaw. But then I realized I could reduce the pressure by putting two small tissue papers on the sides to distribute the pressure and I also think as I wore it for a while it kind of loosened or I got used to it. The other thing is the PU leather kinda feel sticky if you have a shiny bald spot , but with time or say with the use of tissue paper I learned to handle the pressure, but given I did not feel this with HD 660S , 560S, 800S , HE-1 , HE100SE but with this one, says not a lot of thought was given to the comfort. Clamp force may feel a bit high but still felt less than the un-stretched 660S, so that is okay.
Axel Grell mentioned comfort pads will be available sometime in the future.

Soundstage.

It is quite big but not as big as HD800S, or HE1000SE. Listening side by side with HD 660S it felt bigger, I think its bigger than HE-1 too but not as deep as HE-1. Although the soundstage is not as big as HD800S, if you draw your imaginary instruments and singers with HD 800S their positions will seem weird and not make sense, some too close , some too far away but with the OAE-1 it kind of makes sense. But it is smaller than HD 800S and has less airy feeling than it. Even though soundstage felt big I did not mix up its sound with reality, which I did once in a while with HD 800S. I think soundstage and imaging only does not confuse you, the sound has to be detailed enough to make you think the sound may be coming from outside. The sound is surely not as detailed .... more on this later. Once I felt a particular sound was coming from my side a little bit in the back, but the sound itself did not match sounds in the real world much so won't say it was an aha moment. For me even though soundstage imaging is way better than what the price may suggest, it is not anything drastically different as we might expect from the positioning of the drivers. But then again it is probably the third biggest soundstage I have heard next to HE1000Se, and HD 800S.

Bass.

This made me a believer in Axel Grell's theory. Although I noticed bass in multiple tracks, when I heard the drum in Frozen by Madonna in the long instrumental part, I felt the bass hit my face, forehead and neck. I felt the vibration just like Axel said we would !!!!

Starts at 3:10 https://tidal.com/browse/track/1669855?u

I am very sensitive to bloated bass, this did not seem to be bloated or muddy.


Detail retrieval and clarity

If you listen slightly carefully you will feel it has more air and clarity than HD 660S, but its not like when you move to HD 800S and you feel "my whole music listening was a lie" and "how could I bear the 660S" no its not like that but still its clearer.

But still it lags behind 660S, (also HD800S and HE-1 ) in some areas. For example in the song "The way we were" where Barbra Streisand hums in the beginning, all 660S, HD800S HE-1, they all sound so sweet and full (660S is like warm bread, HD 800S is like butter on bread, HE-1 is like honey on bread and butter). But with OAE-1 her humming seems uneven as if some portions of the frequencies are subdued.

https://tidal.com/browse/track/1317337?u

In multiple songs some voices seem somewhat subdued but not muffled. As if weak and some parts missing, but not veiled by something. May be I need to eq that part.
The headphone handles excessive volume really well, so I assume it will respond to EQ well too.

The beep, beeps at the start of the song sweet surrender by Sarah McLachlan also had this issue, they seemed more broken than HD 800S or HE1000SE , speaking from memory here btw https://tidal.com/browse/track/225534413?u

With Cello music you often can feel the bow slide on the strings with the HD 800S, not so much with this one, so some smoothness is missing in that region. But hey remember its $350.

I did not feel any treble spike though.

Portability and Usage

The case is super portable , and solid enough to protect the headphone. Can easily slide in my backpack.

Summary

It is a very good headphone for $350 but cannot compete with the big boys like HD 800S and HE1000SE except for the bass. It is an unfair comparison but somehow we unfairly set our expectations too high given Axel Grell's legacy. If this did beat out HD 800S and HE1000SE in every aspect, Sennheiser and Hifiman would go bankrupt lol. But it surely beats out the pricier HD 660S in my book and it surely beats every headphone I have heard out there in terms of bass. It proves that the concept works as this is probably the maximum amount of soundstage anyone achieved with a 40 mm driver that is not even a ring driver emitting planar waves. It also proves that you can produce clean bass and make your body feel it which none of the headphones I tried 660S, HD 800S, HE100SE or HE-1 did for me. But I felt this with only one song as I mentioned.

Will I keep it ?

Overall I like the sound better than the headphone I am currently using 660S, it sounds clearer and bigger, it has this unique bass which I might miss if I return it. I can fix the comfort issue with tissue paper or some leather and glue and official comfort pads will be available in the future. I need to stop myself from itching till i get the next Sennheiser headphone (hopefully God willing). I believe given it has an Axel Grell signature it will have a good resale value. So I guess I will keep it.

Although I do not feel everything was perfect I think the two concepts regarding the orientation and bass have been proven at least to me.