ZMFheadphones Aeolus

Overview:

Note: I have a new review format coming up soon after the DUNU SA6, I will try and update my old reviews to somewhat of the new format.

Up for review today is the gorgeous ZMF Aeolus in Sapele wood (Aeolus.) The Aeolus is one of the slightly older models from ZMF, not the Verite, or Caldera, but still a really fantastic headphone in its own right. This is the open-back version of the Atticus with TPE membrane drivers. Their impedance is 300 Ohms with a sensitivity of ~97dB/mW and they weigh in at ~445g. You can order them with the usual ZMF options, magnesium or aluminum chassis, Grill and Rod colors, cable terminations, what kind of box you want them to come in, etc. You can add upgrade cables, choose your termination, pick different pads, pick the headband material, and fly out to watch it be made (I’m kidding about that one, but it would be pretty cool.)



I got this one used from another Head-Fier in a trade, so I got to pick NONE of that, but mine came well-appointed with the Wood box, a Norne cable, a neat leather baggy thingy, and that’s about it. So, given the popularity of ZMF headphones, how does the baby brother of the Verite Open sound? To use the words of Rawk0r, the guy I got them from: “they feel like a warm hug.” On with the review!



Build Quality / Comfort:

The Aeolus has really good build quality and feels like a premium product. The unboxing, even on a used pair, was really cool with the wooden box and purple velour padding makes you feel like you just bought a premium product. Dare I say it makes you feel like royalty? Sure, why not – the next thing you’ll notice is the squishy padding on the headband and the beautiful wood on the earcups. Mine came with a tiny chip missing from the spot where a screw keeps the ear cups from rotating too far – a little bit of a design flaw there. That’s about it though, everything else looks good, even on a used pair. Keep in mind that ZMFs are known for losing color on the rods if you get the magnesium chassis and rods since they’re painted. It’s perfectly normal, though I find it to be kind of tacky – others think it gives it style to see the silver color popping through (some people think patina’d cars look good too - to each their own.) Mine is aluminum, which doesn’t have that problem, so it still looks good, but it weighs 35g more (oh noooo – the weight, the crushing weight!)



Moving on to comfort, these are actually pretty light feeling. Having owned the Rosson RAD-0 (600g+), the Aeolus feels just about perfect on the head. There is a comfy set of earpads on them that applies just the right amount of pressure and there are no hotspots to speak of. This is a really comfy headset despite not being as light as the Ether 2 (<300G.) That’s mostly thanks to the squishy padding, which feels like memory foam, and which is thicker than a LOT of padding that comes with some headphones (or just a piece of leather.) So, yes, very comfortable and the cable doesn’t add enough weight to be uncomfortable (stock or Norne.) The stock cable is pretty bad and mine came in 6.35mm. The stock cable is also very microphonic, though lighter than the Norne Drausk.

Just a quick note on the Norne Drausk cable: This thing is the CHONKIEST cable I’ve ever seen, held, used, etc. It is an absolute beast and it is 16 strands, and yes it’s heavy. I don’t even think they make this thing anymore since I only see 8 strand ones on their site. Pretty cool, though it has some memory retention – it's XLR4 so I’ll be using it for the below test.



Sound / Source / Comparisons:

Looking at Crinacle’s frequency response chart, the Aeolus have almost no sub-bass or mid-bass. The mids should come through decently, especially with the hump at 1k. The rest of the tuning after 1k follows the 2018 Harman target pretty closely. These are a very different tuning compared to my JM Audio XTC-Open (XTC-O) which I will be using to compare to these. The XTC-O has significantly more bass and lowered highs compared to the Aeolus. More to come on that comparison below.



I will be driving both headphones from my Cocktail Audio HA500H DAC/AMP with TUUUBESSS! Oh, it has a solid-state also – I’ll also be using that, but I don’t have a good Tenacious D reference for that. I’ll be using the high impedance setting, even though the HA500H drives these just fine on low. I will be playing music from Tidal HiFi with MQA enabled – the HA500H decodes MQA on board (such a cool DAC/AMP.) The HA500H drives these at 37/100 on high gain with a balanced 4-pin XLR connection compared to the 27/100 the XTC-O takes.

As usual, I don’t like breaking down headphones solely by frequency range since every song has bass, mids, and highs (and I can’t tell the difference between vocals at 1900 Hz and 2100 Hz.) So, I will start with bass-heavy songs, then move to mids-focused and lastly highs-focused songs, then break down each song by how all the pieces are presented. You can find my Tidal test tracks playlist in my signature if you want to compare them to your headphones.

The Bass-test song today will be David Guetta’s “I’m Good (Blue)” since it is still one of the best mid-bass/sub-bass test songs I’ve encountered. I am using these in the tube-off setting so that there are no inconsistencies or extra warmth. The mid-bass/sub-bass depth is definitely missing from the intro of this song. You get some decent impact from the intro bass drums, but it doesn’t have anywhere near what you’ll find on the XTC-O, Sony MDR-Z1R, or even the Sennheiser HD820. The Sub-bass isn’t missing, but there’s so little of it, you could easily miss it. These are very mids and somewhat high-focused headphones – that’s not a bad thing, but it is something you need to know if you’re looking for a basshead set of headphones.

The mid-synths and high-synths come in cleanly and somewhere around the middle/front of the soundstage. These don’t have the soundstage of some other headphones (HD820), but they have the more forward mids that I enjoy. Instrument separation is good with solid layering allowing you to tell each instrument apart. It can get a little muddy from time to time, but these are still some of ZMFs cheapest headphones (not counting the T50rp haha.) The XTC-Os have much better mid/sub-bass depth and rumble with even more impact than the Aeolus. The mids are even more forward with a similar soundstage. Despite there being more bass on the XTC-O, it doesn’t overwhelm the music and the detail is better – this is partly due to the beryllium drivers on my XTC-O. XTC-O wins the bass test.

My mids-test song today is The Summer Set’s “Figure Me Out.” This song has piano, vocals, drums, guitars, etc. The piano sounds further back with the vocals in the middle on the Aeolus. On the XTC-O, the vocals and piano are more forward. This provides the Aeolus with the impression of a larger soundstage, though instrument separation is similar. We get a little more of the muddiness on this song that I heard on “I’m Good (Blue.)” The hi-hats come in clearly most of the time on the Aeolus unless the singer is singing loudly. Guitars sound good as well, but there is still some overall muddiness and mixing of the music where it becomes a blur or sound instead of individual instruments. The XTC-O sounds better with the tube on for this song, but that would be cheating, so I won't use it – as previously mentioned, we get a more forward representation of the mids. The bass is FAR more present unsurprisingly and there is better instrument separation. The hi-hats and cymbals come in cleanly on the XTC-O with more overall detail and none of the muddiness you get from the baby ZMF. My preference here is a smaller soundstage, more pronounced mids, and better detail/separation, so the XTC-O wins on this one.



Moving on to the highs-test songs, the first is the sharpness/sibilance test with Panic! At The Disco’s “High Hopes.” I’ve rarely heard the horns in the intro of this song ever sound bad on anything, but the low horns can disappear on some headphones. The Aeolus doesn’t have that problem – the low register horns can be heard, though they’re not as pronounced as I’d like. The soundstage here is really good again, not mind-blowingly large, but medium/medium-large. The mids are more recessed in the soundstage again, but I only hear a very small amount of sibilance – not enough to distract from the song negatively unless you’re really trying to listen for it. The snares can be heard clearly, and I have no issues with a lack of detail or muddiness on this song. The XTC-O hits those low notes even more clearly than the Aeolus in the intro. The mids sound only slightly more forward on this song than the Aeolus – both have a similar soundstage on this song. The ZTC-O has a little more sibilance/sharpness on this song too, but both are about comparable. The snares sound more natural on the Aeolus, but it’s really close. I’d barely give the win to the Aeolus on this round.

To test the highs above 3k Hz, I’ll be using Dream Theater’s “The Alien” to look for the hi-hats and cymbal separation from the rest of the music. On the Aeolus, they’re there, but so blended in that I can hardly hear them, even while trying to hear them. It’s all one big blur of noise with no separation between hits. The drums sound good but don’t have the XTC-O’s impact. The guitar solos sound good if a bit distant. The XTC-O has far better drums in the intro, more impact, and more presence. The bass guitars can be heard more clearly as well. The cymbals and snares come in more clearly on the XTC-O, though they can’t compete with the FAudio Mezzo LE IEM for highs here. The guitar solos also sound better on the XTC-O with a better balance and more body to the guitar. The XTC-O wins this round.



Conclusion:

The Aeolus is a gorgeous and comfortable set of headphones with great padding and solid build quality. If you want that wood piece to make a statement, these are great. If you want your introduction to ZMF and you don’t need/want a ton of bass response, I don’t think you can do better than these. That said, the XTC-O is a better all-around headphone and it’s cheaper too. Now, that’s only with the Beryllium driver on the XTC-O, I haven’t heard the biowool, which may have a similar sound signature to the Aeolus – also, they’re cheaper and have a slightly more robust build quality. Since I rank the XTC-O at/near the top of my Over-ear headphones, the Aeolus coming so closely is an impressive feat and they are a recommended buy.

Some Background:

Aeolus is a new dynamic, open-backed, circumaural headphone from ZMF Headphones, and it is also the realization of a frequent community request. Atticus, the closed sibling of Aeolus, has been a popular high-end flavor-can for the community since it came out about two years ago. In that time, the Atticus has built a cult following for its rich, smooth, and musical tuning, with serious thump. The Atticus was never about neutrality, but about having fun and enjoying music. The Aeolus represents a maturation of that concept, which tempers some of the more exaggerated sonic features of the Atticus, while retaining its character, and bringing a higher level of resolution through its open design.

The Aeolus uses the same TPE driver as the Atticus, so all the differences between the headphones are a result of careful acoustic tuning. By controlling airflow, back-waves, resonance, cup volume, and more, Zach has been able to answer the community’s call for an “open Atticus”. The Aeolus is not meant to be a better Atticus, but instead an offering that gives listeners access to the lush timbre of the Atticus, while trading-off pros and cons where you might often find divides between open and closed headphones. These are namely: isolation, bass extension/quantity, micro-resolution, stage size, image specificity, and evenness of frequency response. The Aeolus is the answer to what an open Atticus would sound like. To find out exactly what that means, you’ll have to stick around.

Bearing all of this in mind, I was very excited to get my hands on the Aeolus for review, and hope to provide useful information for the community, especially given the (soon-ending) pre-order period. I was sent this pair without any requirement that I write a review, and am not being paid here or elsewhere for my reviews.


My Setup:

For this review, I will be running all headphones through my Oppo HA-1, both as a DAC and a headphone amplifier. Music will be run out of my custom-built PC over Spotify Premium via USB to the HA-1. I don’t listen to FLAC for the bulk of my music, and I am most familiar with the tracks to be mentioned, so these 320 kbps versions will be my reference. The highest quality in Spotify was selected, and volume matching was turned off (the settings I always use). Volume across headphone comparisons was matched as much as possible with a BFX digital sound meter sealed to the headphone cups in a cardboard enclosure. All headphone cables used were OFC 4-pin XLR, plugged into the balanced output of the HA-1.


Comparisons:

I will be comparing the Aeolus to the ZMF Auteur, ZMF Vérité, and Sennheiser HD800. For the sake of getting this review out in a timely fashion, I will not be including comparisons to my 007 as I did with the Vérité. I also own an LCD-3F, which is being similarly sidelined. If you’d like comparison notes, let me know what exactly you’d like to know, and I will do my best to answer. I own all of these headphones, and have listened to each of them for a few months at the least (except the Vérité, which is here for review as well).


Test Tracks (Some of Them):

I will be comparing headphones primarily across these, but also other tracks. I don’t make mention of every track in every section where I listened to them, but instead am largely giving my high-level impressions. If you want my thoughts on any particular track or phrase, just ask! I’ve tried to select widely available songs across a spectrum of music that I like and am familiar with.


Track List:


Baralku, by Emancipator, on Baralku


Viices, by Made in Heights, on MADE IN HEIGHTS


Touch, by Daft Punk, on Random Access Memories


House of Cards, by Radiohead, on In Rainbows


Peace Train, by Cat Stevens, on Teaser and the Firecat


Hey You, by Pink Floyd, on The Wall


The Four Seasons, Violin Concerto in G Minor, Op. 8, No. 2, RV 315, Summer III, by Antonio Vivaldi, performed by Adrian Chandler, on The Four Seasons and Concertos for Bassoon and Violin “in tromba marina”


Tamacun - Remastered, by Rodrigo y Gabriela on, Rodrigo y Gabriela (Deluxe)


Warm Foothills, by Alt-J on, This is All Yours


Boomerang, by The Uncluded, on Hokey Fright


Little Sadie, by Crooked Still, on Shaken by a Low Sound


True Affection, by The Blow, on Paper Television


Second 2 None, by Mura Masa and Christine and the Queens, on Mura Masa


Acid, by Ray Barretto, on Acid


ラ・ム・ネ, by Snail’s House, on Ordinary Songs


Build and Comfort:

Given that I have just gone over build in my Vérité review, I won’t go on too long, but let me give an overview of the build of the Aeolus.

The Aeolus is just as well constructed as all of ZMF’s other custom dynamics, that is to say, masterfully. Zach’s designs abound with attention to detail, and high-quality materials. The cups on the unit I have are a pale, unoxidized mahogany, and feature a less ornate grill pattern than that found on the auteur and Vérité, opting for a more sloping and angular pattern. The grill design is a matter of taste, and for my part, I think the grill on the auteur may still be my favorite, partially due to the auteur being my first ZMF open-back. The rod and slider mechanism, as well as double headband are identical to those found on the auteur. The suspension strap and spring steel combination easily adapt, and continue impress with the comfort they provide. Slider adjustment is simple, although it cannot be easily completed while wearing the headphone.

The Aeolus is quite wearable at 445 grams, although about 30 grams can be saved, at a price of $250, on the LTD wood runs of the Aeolus by swapping in the magnesium chassis from the Vérité. The Aeolus will be run in Sapele as the stock wood, and Ziricote for the first LTD run. While on the subject of options, the Vérité pads can be added to any Aeolus order for $60. The unit ships stock with the Universe pads, which I will be using for my review. I will offer brief impressions with the Vérité pads, later on, time permitting.


Listening Impressions:

Bass:

I will only be able to make reference to the Atticus’ bass from a few brief memories, for the sake of those interested to read about it. In general, I am not going to be reviewing the Aeolus as a version of the Atticus, but as its own headphone. With that out of the way, I will say that the bass on the Aeolus is not as elevated in its slamming as that of the Atticus, and that it blends into the midrange more seamlessly. Beyond those broad strokes comparisons, I would really need an Atticus on hand to give insight.

Heard as its own headphone, the bass from the Aeolus is quite satisfying, carrying over some sweetness from the midrange, which we will discuss in a moment. Midbass is more prominent than the sub-bass on the Aeolus, although neither feels out of place. I do enjoy the palpable feeling that powerful sub-bass can impart, and the Aeolus can deliver here. Listening to Massive Attack’s Paradise Circus, and Cane Shuga by Glass Animals, both satisfied in this way, with tactitility to the music that felt cohesive with the overall smoothness that the Aeolus gave to each song. As mentioned, midbass is slightly elevated relative to sub-bass, and is where the TPE driver of the Aeolus shines. Listening to Acid, the bass line came across with excellent substance, and gave a firm foundation to the song, that I sometimes feel isn’t there. The hand drum beats were quick without feeling artificial, and noticing small nuances between each slap was both easy and enjoyable.

Across the frequency spectrum, detail on the Aeolus is reproduced in a very relaxed but competent kind of way. The super scientific analogy that comes to mind is of an expert marksman showing off around a campfire after a few drinks (don’t do this, friends). The shots all hit their mark, but the display is more about having a good time than about absolute focus. What really impresses me is the way in which the Aeolus is, in a very minimally-compromising way, not all about detail, due not to some inherent grain obscuring things, but just because liquidity is emphasized over speed.


Mids:

Oh those creamy mids. Above all other headphones that I have done close listening with, the reproduction of voices on the Aeolus feels the most human. That is not to say that the midrange of the Aeolus has the greatest resolution of any headphone I have heard, but in terms of natural and smooth reproduction of voices, these are an 11/10. Acoustic instruments benefit from this quality as well, but I think because of how much time we spend hearing voices every day, the Aeolus really struck me with regards to them. The midrange response slopes very gently downward as it transitions out of the mid-bass, and carries on with this trend into the lower treble, up until around 5k or so, where the response rises. The combination of this tuning and the lush nature of the Aeolus makes them eminently crankable. It is so easy to listen to the Aeolus really loud. Not because detail feels absent, but because they are just so far from piercing or shrill, and their feeling of musicality didn’t break-up in any of my listening.

Impact in the midrange struck a nice balance, providing a sense of dynamism, without forcing sounds. Edges of notes could stand to be a bit more refined, moreso on trailing edges, but the smoothing that the Aeolus offers did make music easier to get into, and can compensate for some less-than-ideal production value. Spatial placement seems to be less affected by this smoothing, but we will get into these technicalities more broadly in a bit. I appreciate that the sloping of the midrange was tuned to focus on musicality and pleasing naturalness, but does not feel withdrawn or sucked-out. The rise into the lower treble also plays a part in giving back a bit of energy to balance the lush tone of the midrange. The quality, and specifically the enjoyability of the Aeolus’ midrange really is hard to overstate. A capella and tracks with a strong vocal presence satisfy in a visceral way that I don’t often feel when listening to headphones. Drum and acoustic guitar pairings sound damn good in a similar way.


Treble:

The treble of the Aeolus begins by lifting up out of the upper-midrange, and then sloping down again around 10k. There is a bit of dip around 7-8k, but this was only really noticeable on a tone generator. The overall treble presentation continues the trend of smoothness from the rest of the frequency response, although I find this effect to be a bit too pronounced during critical listening. While listening to the Aeolus for fun, or in the background, this more gentle treble presentation is ideal, but when I really want to hear that last bit of bite from violins, or a little edge from the high notes of a sax riff, notes are a bit softer in their attack than I would like. That said, the substance and body of treble notes is still very much there, and impact is solid, if not the pinpoint warhead that I heard a few weeks ago with the Vérité.

To give an example, the chimes and vibraphone (I think that’s what it is) on Viices both sounded clear and full, but lacked some of the sparkle that I have heard from them on other headphones. That said, the same tuning choice/driver property that I believe is causing this presentation is rendering the female singer’s voice enchantingly, and giving me great taut rumble from the bass line. This slightly-damped treble presentation is not distracting or large in its effect, but it does contribute to the overall tone of the Aeolus. There is a small tradeoff being made here, but the Aeolus is doing a good job of convincing me of its presentation.


Technicalities (Imaging, soundstage, detail retrieval, transients, dynamics, separation etc.):

On binaural recordings, the Aeolus can reach wide, and cast a large stage, however, as I’ve found to be the case across the ZMF line, Zach’s headphones won’t make songs sound wide arbitrarily. The Aeolus doesn’t have the quite the three-dimensionality to its staging that you might find on the Vérité or other summit-fi headphones. However, the left-right stage was certainly outside my head, and could reach outside where the headphones end as well. Front to back, the Aeolus also had solid staging, about on par with its vertical presentation, which surprised me. Both the X and Z axes did a better job precisely placing sounds than I expected. To speak more to imaging, specificity on the Aeolus is pretty good, in a way that is consistent with the overall timbre of the headphones. What I mean here is that the Aeolus presents warm, with an emphasis on liquidity. These characteristics can make the edges of sounds harder to locate, and interferes with what can sometimes be mistakenly used as a proxy for detail and precision, i.e. a bright tuning. Despite this, separation is strong enough to satisfy in most cases. I believe that this is due to the Aeolus’ stage pushing out reasonably far, and resolving fairly small increments of space along each axis. All told, it took me a bit of time to understand the actual imaging performance of the Aeolus. In the end, I think only serious detail-heads would trade the natural tone of the Aeolus for that extra 5-10% of imaging specificity. If we could somehow have both, that would be awesome, but we don’t live in that world, at this price, just yet.


In line with, and I believe acoustically related to image placement, is the ability to faithfully and quickly reproduce transient edges. The Aeolus, for similar reasons as those just mentioned, is solid, but not outstanding in transient reproduction. It probably doesn’t help the Aeolus’ case that I am coming off of the Vérité review right now, but the edges of notes on the Aeolus fade in the way that they might in an a modestly damped venue. Trailing edges of notes, especially, linger for just a hair longer, and with a hair less control, than I would like. The first of these factors, the longer decay, is actually pretty great sounding on many acoustic songs, as it does give a more “live” sound. Toward the latter, control of decay is good, but not excellent on my unit. To be fair, wood choice could make a difference here, as might the Vérité pads, both of which are user-selectable to varying degrees. Obviously, I need to review the unit from a familiar baseline, but I’d imagine that there are also systems out there that would help with decay. Leading edges are better controlled, and are part of what give the Aeolus its liquid character, coming into place smoothly, but with impact.

Macro dynamics, are really satisfying and powerful, without feeling bloated or overly thunderous. The Aeolus handles changes in dynamics quite well, especially given its speed relative to other headphones up for comparison today, even across quick passages. Micro dynamics are resolved well, although not at summit-fi (Utopia, 009, Vérité, etc.) levels. Similarly, overall detail retrieval is strong, and detail presentation feels neither forceful nor aggressive. Breaths, rustles, variation between “identical” riffs etc. are reproduced, but you’ll need to listen if you want to really absorb each, and although each detail feels represented, there is undoubtedly more to be pulled out of the mix by a headphone that prioritizes absolute resolution. Overall, the technicalities of the Aeolus are very consistent with the tuning of the headphone, which makes for a coherent experience that is easy to dive into and enjoy for many hours.

Universe Pads vs. Vérité Pads

Not a stock option, but if people are interested, I’ll let you know.


Headphone Comparisons:

Aeolus vs. auteur (auteur pads, mahogany):

As the new middle child in the ZMF open-backed line, the auteur is likely the reference point of most interest in regards to the Aeolus and Vérité releases. If you read my Vérité review, you know that the auteur is the more neutral of those two headphones. It should be unsurprising, then, to hear that between the Aeolus and the auteur, the latter is again the more neutral. I listen to my auteur with the auteur pads, and so with it am listening to what I consider one of the most neutral high-end headphones available today. I have owned my auteur for about a year, and have been excited for a while to compare the open designs for each of these drivers to each other. As a point of reference, my first ZMF purchase came after a few hours of comparing the Atticus to the Eikon, and me going with the latter.

Beginning with the bass, the auteur maintained and reproduced subbass texture better than the did Aeolus. Around the mid/upper bass or lower midrange, the timbre of the Aeolus began to win me over. I heard an about equal amount of slam from both headphones in the bass range, but it was distributed differently, with the auteur having more force lower down. The Aeolus sounded a bit elevated in the midbass compared to the auteur as well, and had a weight to its sound that the auteur lacked. What really differentiated these headphones in terms of their bass, beyond FR differences, is how the bass impact from each of these headphones presented. The auteur hits faster than the Aeolus, and low down, hits more firmly, but also backs off more quickly. In contrast, the Aeolus takes until the midbass to punch hard in terms of peak quality and quantity, and lingers in its force just a bit longer. What this conveys overall is a fast and detailed rumble to the auteur, and a more liquid and dark tone to the Aeolus. I tend to prefer the bass presentation of the auteur, but having owned it for over a year at this point, the mere exposure effect is almost definitely playing a role in dictating my preference.

In the midrange, pretty much throughout, the smooth and lifelike quality of voices and guitars on the Aeolus did huge work on my heartstrings. The timbre of the mids on the Aeolus is, to my ear, more satisfying. With that said, the actual FR of the auteur across the midrange is closer to what I want to hear. The auteur came across as a bit bright, compared to the mids of the Aeolus, both because they are elevated in volume, and because of the auteur is less lush in its tuning. There are some cases too, where the auteur comes across as more lifelike, such as in cymbal reproduction, where the fundamental tang and sparkle cymbals is more energetic and bell-like. Preference across genres here is really hard to decide. In the songs that gel with the Aeolus’ tuning (read: most rock, jazz, vocal, electronic, and hip-hop music), its midrange beats that of the auteur, but for genre-agnostic midrange consistency, the auteur would be my pick.

The treble range is probably what sets these headphones apart the most, in terms of their frequency responses and timbral goals. The auteur really nails what I prefer for treble reproduction: a little controlled shimmer, just shy of venturing into being splashy or glaring. The Aeolus hesitates a bit further from this line than I would prefer, and is a bit slower to resolve edges than the auteur, so its treble feels a bit less lively. That said, the Aeolus never ventures into the land of sibilance, and makes less well recorded music, which can be quite irritating in the treble range, much easier to listen to. As I mentioned in my Vérité review, the Aeolus really saved the day when I wanted to listen to more mainstream hip hop and some electronic music. In orchestral music, however, such as The Four Seasons - Winter in F Minor, violins are given the extra bite they need from the auteur. In some recordings, the more relaxed tone of the Aeolus did capture the grandeur of the orchestra as whole better, but in these cases, the auteur enabled me to pick into the mix that bit more. I’m slightly auteur leaning on the treble, at least for well-recorded music.

Technicalities of these headphones are not worlds apart, but they are worth getting into. Layered effects are, as mentioned, easier to pick apart on the auteur, which also has a bit more refinement in its transients. As a result, however, the auteur loses out on the lushness that the Aeolus gives to many acoustic instruments, which feathers the edges of notes into what you’d be more likely to hear in a live performance. The image is a touch more defined on the auteur, and also a bit more three dimensional. Width of the stage goes just slightly to the Aeolus, although the stage’s edges also feel a bit more diffuse. Dynamic reproduction, in terms of impact, goes slightly to the Aeolus, however the precision that microdynamics, especially, demand are better reproduced by the auteur. Decay on the Aeolus is more live and musical sounding, and notes seem to be more part of the music, rather than their own events.

I have grown used to the auteur, and so, in most cases, prefer it to the Aeolus. With that said, if I haven’t listened to music yet on any given day, and I reach for either headphone, I usually have a larger and more pleasant impression sooner listening with the Aeolus. The naturalness with which it presents music makes me forget that I have heard it another way before, and has me bobbing my head, enjoying. When A/Bing quickly with the auteur, I am reminded just what I value about the latter, but in more casual circumstances, I’m all smiles when the Aeolus is on my head.


Aeolus vs. HD800:

These headphones are way better complements than they are competitors. This comparison honestly feels a little silly. Granted, they are both 300 ohm, open-backed, circumaural, dynamic driver headphones, but the similarities end there. Due to this, and for the sake of getting this review out ASAP, I will not go into as much depth with this comparison. Where the Aeolus is downsloping, mid-bass-to-mids focused, and all about musical liquidity, the HD800 is bass-light, all about technical finesse, and quite lively in the treble region. Comfort on both headphones is great, although for very different reasons. The HD800 focuses on being light and spread out over the ear with thin padding, where the Aeolus is heavier, but amply cushioned, and luxurious feeling.

Let’s begin to unpack how each of these headphones reproduces music. On Viices, for example, the opening taps on the HD800 sound like suggestions, or gentle meanderings, while on the Aeolus there is a substance and weight, albeit small, to each impact. The female lead’s voice is also much more forward and organic on the Aeolus. On Bubble Tea, by dark cat, the Aeolus and HD800 create wildly different experiences. From the former, the song focuses on the female vocalist, and impact from the bassline. Meanwhile, the HD800 plays back a rapid and airy track, with greater detail, but also a fair amount of shrillness from the high-frequency chime notes. Across a range of songs, the peaky treble of the HD800 makes it hard to justify over the Aeolus especially, given its polar opposite, musical reproduction.

In terms of technicalities, the stage on the HD800 is obviously deeper and wider than the Aeolus, although differences in height are less pronounced. Speed also goes to the HD800, but dynamics are really a tossup. The HD800 is faster, so in this sense, its dynamic swings feel quite pronounced, but given the large gap in impact it gives up to the Aeolus, dynamics on the latter feel more...dynamic. More obvious resolution of micro-detail on the HD800 does make dynamics on this scale more noticeable, but the Aeolus resolves at nearly the same level, and with a liquidity that is less fatiguing than the presentation of the HD800 in this area.

There are numerous competitive offerings around this price, but few make so obvious the ways in which the HD800 misses the mark in enjoyability. What the Aeolus sacrifices in absolute resolution, staging, and speed compared to the HD800, they more than make up for in terms of musicality, impact, and vocal realism.


Vérité vs. Aeolus (copied from Vérité review):

The Vérité and Aeolus are certainly not in the same price category, but given that the release of two new ZMF headphones invites comparison, and that I have the Aeolus in for review as well, let’s get into it.

Build is not really a category that deserves much time. The Vérité is a bit lighter due to the Mg chassis. Both headphones are finished beautifully, and built durably. I will go into a description of the Aeolus’ build in its review, coming Soon™.

To get right to sound, the Aeolus is just a freaking fun headphone, with a nice jump in technicalities and evenness as compared to the Atticus, that makes it so easy to listen to. More than any headphone in this review, including the Vérité, I found myself bobbing my head, or up and dancing, listening to the Aeolus. It’s not as technically proficient as the Vérité, it’s not as fast, controlled, holographic, or detailed, but it is a massive contender in the ~$1,000 headphone market. The mids on the Aeolus maintain a lush and inviting character that Atticus owners will know well, with guitars and vocals coming through especially in an exceedingly natural way. However, the mids are now transitioned into from a less booming, but still punchy, bass range, and are followed by treble that I think needs just a bit more bite on some classical tracks, but which makes a lot more recordings sound good. I still need to see how the Vérité pads alter the response of the Aeolus, and have a hopeful guess that they will bring the treble to an awesome spot.

Compared to the Vérité, all of this results in a headphone that is more friendly and forgiving, but less wowing and engrossing. The Vérité can resolve to an extreme, but would not be my go-to choice for “low-fi beats to study to” (I hope for obvious reasons). Beyond the fact that I would feel a bit guilty ignoring the Vérité, it is good at being the microscope with musicality that the HD800 never was, and the headphone with slam and speed that doesn’t drill detail into your ears with its metallic tuning. The Vérité isn’t a headphone that’s easy to put on the back burner mentally, despite its somewhat down-sloping tuning. Meanwhile, the Aeolus presents a great value for the enthusiast who wants a take on the ZMF sound that is less about absolute technical proficiency, and more about fun. That said, the Aeolus does take a big step toward traditional audiophile characteristics compared to the Atticus, and I think many people will love it for that reason.


Closing Thoughts:

More than any other headphone I have on hand, the Aeolus makes me forget about my system and just jam out. More often than we’d probably all like to admit, that’s all we want out of a headphone, a good time with the music. To be fair, there is absolutely still space and pleasure to be found in absolute resolution and speed, and there are headphones which cater to that desire. That said, the warm tuning and lush presentation of the Aeolus presents a more refined and audiophile-friendly version of what the Atticus made available a few years ago: a high-end intersection of pleasure and resolution. Neither sibling-headphone obviates the other, and the Aeolus is a very attractive offering in the ZMF line, as well as in the ~$1,000 headphone world overall. For the listener who wants to enjoy first and go detail-hunting second, the Aeolus is a great choice. Overall, the rich and impactful sound, coupled with the strong-enough resolution of the Aeolus makes it easy to recommend to those searching for a new headphone to enjoy, in the $1,000 price range.

Thank you to Zach and ZMF for creating the Aeolus, and sending them over for me to check out. I have enjoyed my time with the Aeolus a great deal, and appreciate the opportunity to review them.


Specs:

Frequency Response: Approximately 10 Hz to 25 KHZ

Impedance: 300 Ohms

Sensitivity: 99 dB/mW

Warranty: Lifetime for Driver, 3 years parts and mechanical

Weight (est.): 445g

Pads: Universe (Vérité pads optional +$60)

Case: Seahorse SE 430


Price: $999 pre-order, $1199 list price

Disclaimer: The Aeolus was provided to me by Zach to use for a few weeks with no stipulation I had to write a review. My sound preferences lean slightly warm of neutral. My main gear consists of Arcam CD73 > Yggy A2 > ZDS > Auteur/HD800S/HD600 family.

Aeolus Review



Intro

When Zach released the Eikon and Atticus two years ago, like most I initially fell for the Eikon. It had a linear and natural timbre that most closed backs just could not achieve. The Atticus was more of a slow burn, gaining a strong following as time went on. The Atticus is a colored headphone and it embraces it wholeheartedly. I myself found that I preferred it over the Eikon, even calling it the best headphone for metal. Oddly enough, though it was far from neutral, the technicalities of the Atticus challenged and even exceeded the Eikon in some areas. Myself and others clamored for an open version using this same TPE driver. The Aeolus is that headphone.

Comfort/Build

The Aeolus uses the same design as all of Zachs previous headphones (using the newer and lighter headband employed first on the Auteur last year). They are made entirely of wood, metal and real leather (suede is available in place of leather as an option). While on the heavier side (~445grams depending on wood) it wears its weight well due to the excellent weight distribution. This is also among the lighter ZMF headphones. If you are coming from an Eikon, Atticus or Auteur (particularly the heavier wood versions) these are noticeably lighter. I can wear these for hours without discomfort. Ear pads are plush and comfy as usual. Saple is the default wood used and it looks really nice, has sort of a similar look as Mahogany. Smells really good too!

Sound

Intro

Over the years, many have claimed fame as being a “Super HD650”. I have ALWAYS found this to not be the case. My first full size expensive headphone I purchased years ago was the HD595 and soon after, the HD650. That same pair still lives in rotation among many more expensive headphones I own. While these “fake” super hd650s were sometimes good on their own merits, I have never found them to be good enough (or similar enough) to replace my hd650. Just to name a few that have worn the name super 650 are the Elear, Ether Flow, PMx2, Atticus and more. While some of these are fantastic headphones, they were never super 650s to me. In my opinion, the Aeolus is the first headphone that will be called so and actually deserve it.



VS Sennheiser HD650

Quick reference:
Quality
Bass: Aeolus > 650
Mids: Aeolus = 650
Treble: Aeolus > 650
Quantity
Bass: Aeolus > 650
Treble Aeolus > 650

Bass:

Both the 650 and the Aeolus have similar bass profiles. They both are elevated and centered around the mid bass. However there are a few attributes that make the Aeolus stand above. Most importantly, bass distortion on the Aeolus is lower than the 650. The 650 has a bit of a muddy haze in the lows compared to the cleaner and faster Aeolus. You can really notice this when listening to bass heavy music. The Aeolus bass is elevated further over the 650, though I wouldn't go as far to call it a basshead headphone (maybe refined basshead). Sub bass is no contest, the Aeolus smokes the 650. While the 650 quickly rolls off after 50hz or so, the Aeolus has usable bass down to the limits of human hearing. (don't expect quite the sub bass levels of the Eikon though)

Mids:

This is where some of those super 650 wannabes start to fall apart. The mids on the Aeolus are smooth and cohesive. Not recessed, not pushed up into honk city. Just like the Atticus, it has a very natural and slightly romantic (warm) tone to the mids. Resolution is excellent and dynamics and slight changes in pitch are easily heard. You can actually listen to complex orchestral passages and not miss any detail. This is where the Aeolus and 650 really come close together. However, to get as much resolution from the 650 as you get from the Aeolus even from a modest setup, you would need to scale up your gear to really show what the 650 is capable of (in regards to the Aeolus, the 650 is still the king of budget setups imo).

Treble:

Any “fake” super 650s that made it here are now gone (looking at you Elear and your huge canyon between the upper mids and lower treble). This region of transition from mids to highs makes and breaks many headphones, fortunately for the Aeolus it passes easily. There is a little bit more energy there in the Aeolus than the 650, but not as much as the 600 and 580. Going up into the treble proper, the Aeolus continues to have just a smidge more energy than the 650. Some may prefer this while other may not. Some find the 650 to be too dark in the highs. The Auteur has been my primary headphone for a year which has more energy in the highs as well. I find the Aeolus to be between the two in levels. Listening to poorly recorded bright metal with the Aeolus works well. While the Aeolus will not smooth it over, it doesn't bring about fatigue either.

Sound stage and imaging are both superior on the Aeolus, but neither headphones are near best in class in this area. If your someone who demands the widest, most diffuse sound stage around and refuse to buy speakers, the hd800 is about your best option.



VS Auteur

Will touch just a bit on the main differences with the Auteur. See my Auteur review for a more in depth look of Zachs first open back headphone. It has been my main reference for a year now.

Quick reference
Quality
Bass: Auteur > Aeolus
Mids: Aeolus = Auteur
Treble: Auteur > Aeolus
Quantity
Bass: Aeolus > Auteur
Treble: Auteur > Aeolus

The Aeolus and Auteur are different enough that they would appeal to two different types of preferences (or genres if you have a wide musical taste). Some of the basic differences of the Eikon and Atticus transfer over to their open variants. I think the Auteur is a better all rounder and is definitely closer to neutral than the Aeolus.

Bass:

Auteur goes deeper and slams more in the sub bass. Auteurs sub/mid bass peaks at about 50hz, lower than the Aeolus. The Auteur remains pretty linear through the rest of the bass into the lower mids while the Aeolus has the mid bass bump. Auteur is a bit cleaner, but I feel like the Aeolus is a bit faster. Neither bass profile is better than the other, it really comes down to your preference.

Mids:

The Auteur has slightly more resolution and micro detail, but they are so close it could just be gear matching/preference playing a roll. Otherwise the mids are pretty linear throughout on both with a slight dip before 5k on the Auteur and a bit more forwardness in the upper mids on the Aeolus.

Treble:

The Aeolus treble is just a little less in elevation in relation to the Auteur (however a pad swap on the Auteurs brings them about on par on level). The Auteur has this unique holographic soundstage that I haven't heard before on a headphone. While not really large, it is incredibly realistic with excellent imaging. The Aeolus can't quite match the Auteur here, but it's close. Both headphones have excellent transitions from bass-mids-treble.

If it seems like I prefer the Auteur, that is because I do. Unlike their closed counterparts, I prefer the biocellulose headphone. I think it has an overall edge when taken as a whole, however that comes at a cost as the Auteur is several hundred dollars more expensive than the Aeolus. Your musical and tonal preferences can easily have you preferring the Aeolus over the Auteur as well. They are closer in overall quality than the pricing would lead you to believe.

Sounds Amazing

Yes, it does, but it is not a perfect headphone. That doesn't objectively exist (of course there can be a perfect headphone for YOU subjectively). The Aeolus has a very cohesive sound from top to bottom that commits little faults. I feel like if your one to lean towards a neutral headphone, the Aeolus may be a little too warm of neutral for you though (unless you like a good contrast to your main headphone, like the Atticus has been to my Auteur and 800S). The treble, while non-fatiguing can be a little elevated to some who are super sensitive to that. It is not as smooth as the 650 in the highs, it can sound rough depending on your tolerances. This could all be positives or negatives depending on the person.



Gear

Just like the Auteur and 650, the Aeolus does not need kilobuck tube gear to sound fantastic. Also just like the Auteur and 650, it will scale up well with kilobuck tube gear. I don't feel it scales quite as much as either of them though. That doesn't mean that the 650 surpasses the Aeolus on something like my ZDS, just that the difference between my Vali 2 and ZDS is more pronounced with my 650 and Auteur than it is with the Aeolus. It still definitely benefits from good amplification. I'm particularly a fan of tubes over solid state. Personally I recommend Schiit on the low end of cost to DNA and Eddie Current on the high end. One of these days I'll finally hear a Glenn amp, many ZMF users swear by them as well. Gear, like headphones are a very personal taste though. You have to find the right synergy that goes along with your sound preferences. Having said that, I would not recommend overly warm gear with the Aeolus. The Aeolus itself is already a rather warm headphone and could lead to too much of a good thing imo.

Conclusion

It took two years but us Atticus fans finally got our open Atticus. The Aeolus is an excellent headphone and excels at not giving a schiit about its colored nature. It is all the better for it. The price is right too. Sitting right at $999 on preorder ($1199 after) , I think this hits a sweet spot among flagship headphones today. It has that warm, romantic punch of the Atticus while pushing closer to neutral, making for an excellent genre master or even all rounder depending on your preferences.