General Information



  • Type: Closed-Back
  • Driver: Dyanmic Atrium driver
  • Impedance: 300 Ohms
  • Damping: Atrium Damping System
  • Wood at launch: Cherry (stock), Olive (limited edition)
  • Weight: ~500 grams (depending on choice of wood and chassis)

Latest reviews


100+ Head-Fier
Atrium Closed Italian Olive Wood - Un Classico
Pros: Fun bass-centric tuning
That ZMF sound, but with a unique energetic twist
Great resolution and speed for biocellulose
Very comfortable
Spacious sound for a closed back
Cons: Some may prefer the VC
Scales well - meaning you'll have less money eventually
Atrium Closed Header 3.jpg


I’d like to start this review off by acknowledging my bias for ZMF gear. I think Zach and his team are making headphones that, while technically proficient, really put musicality and enjoyment first. I respect that there is another engineering philosophy that searches for truth in neutrality, but I don’t connect with that. Hearing the Caldera at this past CanJam SoCal was a small revelation. I bought a demo unit right there on the spot because it was absolutely the best thing I had heard. Listening in the months since the show, the Caldera continues to excavate new life in songs and keep me on the edge of my seat. The Atrium Closed continues ZMFs streak of excellent TOTL entries that take advantage of their magic ADS damping system. The headphone wizards are at work, and the R&D is paying off.



After reaching out with some other gear inquiries, Zach graciously sent me an absolutely stunning demo of the Atrium Closed Italian Olive Wood to test out. It may be my Italian American heritage kicking it, but this thing is a knockout. Most of you know that owning a ZMF headphone is sort of like owning an instrument crafted by some esteemed luthier. As objects they have a mental draw like the One Ring, always occupying a background processes or peripheral glance when docked on the desk. The detailing and design choices on this particular LTD batch of olive woods are impeccable. The olive green “B.B.B.” or Bull Bolster Band strap is new to me, and I enjoy the fit and finish of it. I found the comfort level to be equal to the standard strap - which I like a lot. It does offer a bit more support at the cost of a larger area of matted hair. The wood itself has beautiful ribboning and stratification, and the finish is a matte oil, which I personally favor over a gloss. The internet has varying statistics on the janka hardness rating for olive wood, but it is a harder wood and I’ve read that tightens up the bass frequencies compared to the stock wood. Good distribution makes the on-head weight seem relatively equal to me between this, my Caldera and my VC. The Verité is actually much lighter, but you wouldn't know it.

Here are the ZMF gang's measurements in grams:

Caldera Oak - 558.3

Atrium Closed Olive Wood - 559.1

Verité Closed Monkeypod - 486.9



Zach had warned me that this demo was not burnt in and I can attest to the dramatic impact of burn in on the Atrium driver. Over the first few days the top end was a little too spicy, but as time passed the driver mellowed and matured. I’ve seen Zach mention that the bio-cellulose drivers are the most transformed over the burn-in period.



For reference my source chain is MacBook Pro > Tidal > Gustard R26 > Cayin HA300 mkii. My current tube load out is Elrog 300Bs, Linlai Elite 6SN7s, GE 22DE4 rectifiers. The AC isn’t too picky with impedance, but I’ve been listening on medium and high. I'm also using a WyWire Platinum cable for all my ZMF headphones at the moment. I have yet to test out the top tier ZMF cables, but I’m sure those are fantastic as well. Side note: I tried the AC on the Mojo 2 and Magni Piety and it sounded great on both of those too. Slightly less holographic without the magic of tubes.


You’ve probably jumped here. Good on you. Let me start with the hype that the Atrium Closed (AC) is my favorite closed back headphone yet. I never owned the Atrium Open (AO), but I have heard it a few times. The AC does capture the Atrium Open sound profile with a touch of intimacy that I actually love. The tuning of the AC is a bit V shaped in my mind as compared to AO and the Verité. You have wonderfully impactful sub bass and crisp upper treble. My mind always relates this sound signature to a “hifi” tuning, but that gets thrown around as a negative. It works here. I concede that the Elrogs and the LinLai are probably doubling down on that hifi vibe.



Like I said in my opening, the treble started out real spicy and then chilled out. I will say that it is still commanding. This spicy meatball didn’t retire and move to Florida. There is an enjoyable bite and sizzle to it. As someone who is very, very sensitive to the presence region, this headphone is not fatiguing or shouty to me in the upper mid transition zone. It creeps up there sometimes, but never steps over the line. Conversely, VC has a presence region I could never fully tame, though I love the sound. On graphs the AC looks like it could be too energetic in the presence region as compared to the VC even, but when listening to the total picture the AC comes off more relaxed and balanced to me.

The mids are still the delicious euphonic ZMF mids, but they sit a little deeper in the mix than the Verité. This zone makes or breaks the realism of instrument tone for me. Even with the pushed back mids, the AC does not disappoint in realism or euphony. I’d put the Atrium mid tuning in that lineage of the Sennheiser HD650. For me ZMF just gets mids right no matter what.

The mid bass slopes down a little which could be a deal breaker for me, but in this application it is *chef’s kiss*. If the mid bass was much higher the sheer quantity of bass could have been overwhelming. The sub bass has deservedly garnered a lot of praise, but this does not rumble your head like some Fostex dynamics. I used to have the Drop Fostex TH-X00 and you could actually feel the bass pressure vibrating your head if you had the volume up too loud. The AC bass is substantial, but tasteful. Music feels lush and weighty, but equally clean and tight. If you’re after a pure sub bass monster this probably isn’t the right fit.

There are a few tracks I've listened to after posting this that make me feel like I may have been wrong about the Fostex having more intense bass rumble. I want to stress that the AC really does bring it. I think the difference between this and the Drop Fostex is that the top end is so, so good on the AC. Also the bass doesn't feel like it saps other areas of the spectrum when the driver goes into bass rumble mode. With the Fostex it could feel like the bass at times limited higher frequencies. None of that here. The head vibration sensation could have to do with the differences in how this and the Fostex are ported. Keep in mind my experience is limited to the harder wood AC. Big, clean bass.


Staging is decently wide for a closed back. The space sounds natural to me. I dislike when the stage feels artificially wide in a closed back. The AC has a more intimate presentation than the VC, but I never once thought about that until doing back and forth switching. I think this perception is due in part to the VC’s cup depth, driver speed and boosted upper mids. My VC is a much softer monkeypod wood which could contribute to the difference as well. I’d give the technical win to the VC, but my preference win to the AC. If I’m putting on my closed back headphones, I don’t mind them to feel a little more intimate. Depth-wise I know the AO was touted as highly holographic, but to me the VC with Universe pads and the AC have a similar three dimensionality.

EDIT: I've read people saying they find the AC to be wider than the VC. I had to go back and really A/B to see if I was totally wrong (which is very likely). I think the AC's emphasis on the top and bottom of the spectrum can make it feel wider, but the VC's ability to separate detail and place instruments a little more precisely gives my brain more of an illusion of 3D space. I'm using the Universe Solid pad which can be more holographic. The more mid-centric tuning of the VC actually works against it in the perception of space when A/B with the AC. Switching back and forth quickly can make the VC feel a little congested or nasally. I don't think it is, but brighter upper mids and treble of the AC gives it a cleaner / airier feel when jumping quickly back and forth. If you like the VC's soundstage you won't be disappointed with the AC.



In the contest of closed backs, the VC isolates individual instruments more precisely through the speed of its Beryllium coated driver. The gap isn’t huge and ultimately this becomes a decision of taste in my opinion. The AC’s slightly slower driver speed / decay contributes to that organic sound everyone loves with biocellulouse. Beryllium aside, the AC feels quick and reactive to me. The Caldera obviously widens the gap measurably on speed and separation, but it seems unfair to put them in the same technical race.


Oh, sorry I didn’t hear you come up. As with the VC passive isolation is great. The clamp force feels just right out of the box for me. It effectively mutes my very clacky mechanical keyboard and jet engine air filter.



ZMF has a growing library of Caldera pads that can work on the AC. As with all other ZMFs, pads influence the sound dramatically. I typically end up favoring the stock choice, but as a professional tinkerer I must test all options in the name of science.

Caldera Thin (Stock) - Nice bass impact and definition. Very natural sound to instruments and voices. Good treble articulation. Obvious why it is the stock pad.

Caldera Suede - I don’t like this pairing personally. You’re losing a lot of the sub bass that makes this headphone so fun. I also don’t find the suede particularly smoothing. When you subtract that bass, the perceived treble goes way up to my ears. Comfort level is supreme though.

Caldera Regular - I like this pairing on some songs. It is a subtly darker and looser sound.

Caldera Thick aka Bold - This takes some definition out of the bass and makes it bouncier and more reflective. Pushes the treble back a touch. I thought these pads would be a quick no, but I’m not hating the sound at all.

Caldera Cowhide Thin - I think the mids come up with these, but I’m not a fan of this pairing. Treble gets too harsh for my taste.



Actually, these headphones are friendly little guys, and they dislike the allusion to guns. Here is quick stream of consciousness comparisons between all the headphones on my bench right now to help you triangulate the AC sound:

Jake Xerxes Fussell - Love Farewell

AC w Caldera Thin - The AC does really well with acoustic instrumentation. Very natural sound to the strings and voices. The bass lift adds fun flavor to every track.

VC w Universe Solids - the VC sounds much darker to me on this song which surprised me. Darker treble / brighter mids. The instrument separation is ever-so-slightly better than the AC, but I still enjoy the AC more due to my preference for its tonal balance.

Caldera w Caldera Thick - wheew boy I mean the Caldera is like watching something in 8k ear-o-vision. The depth and detail of the Caldera are just different as a planar. Interestingly I think the AC shares more in common the Caldera tuning than the VC. The Caldera has less boost to the sub bass, but it has a touch more mid bass and more impact. The overall quantity of bass perception is similar between the two. The mids are a little more forward in the mix on the Caldera.

Meze Empyrean w Elite pads – (Elite pads and WyWire Platinum bring the sound of these somewhere between Empys and Elites.) The treble is a little darker than the AC. A more laid-back vibe than the ZMF gang. The planar nature wins on speed and separation, but the AC tonally sounds more natural again.

6xx - Still the best value in headphones. There is a lot in common with the AC in tone. The AC is going to win in all the technicalities. The 6xx mids are more forward and the bass emphasis is mid not sub. The vocals and instruments here sound fantastic. The AC’s focus on upper treble gives it more sizzle and crisp detailing than the 6xx.

Grado Hemp w F-Cush - The upper treble has a darker tone than the AC, but the presence region is a little more shouty. Lots of mid bass, but obviously no sub bass. What can you say? - grado sound.

Blake Mills - May Later

AC w Caldera Thin – Full, lush encompassing low end with a lot of ear tickles on plucked instruments. Very organic tone on the euphonic multi-tracked vocals.

VC w Universe Solids - Mids much closer in the mix again and brighter. This track brings it with the bass on the VC. More detail to the string plucks. Wider stereo image than the AC.

Caldera w Caldera Thick - Again more open and spacious than AC. More strata of layers into the music and between instruments. Vocals are closer, but very similar mid tuning. The curve feels more linear than AC, but it shares the lushness. Bass has a lot of definition and dimensionality on the Caldera.

Meze Empyrean w Elite pads - Darker treble, but still has that top sparkle. More bloomy low end. More definition to plucks as expected.

6xx - Similarly wonderful lushness. Vocals are pulled closer than AC and are very natural.

Grado Hemp w F-Cush - the bass is big, but all over the mix. Mids are fun but weird. Grado, fun but weird.

Lump, Laura Marling, Mike Lindsay - Paradise

AC w Caldera Thin - I think the AC does synth sub bass like this very well. Really great texture and impact. Female vocals have a lot of crispness with the added detail. The tuning flirts with sibilance in highlighting S’s in female vocals, but it doesn’t get there. I’ll reiterate that is intensified by my detail-oriented tube loadout.

VC w Universe Solids - Synth bass level is lower, but still impactful. VC does female vocals nicely. Less flirtation with sibilance due to the darker upper treble. Mids closer again.

Caldera w Caldera Thick - Less sub bass elevation than AC on the synth - closer level to VC. Similar representation of female vocals but woven into a different place in the mix.

Meze Empyrean w Elite pads - Even less sub on the synth. Very smooth and spacious sound. Silky female vocals. This is the most laid back of the headphones on this track. It somehow captures both hifi and chill vibes.

6xx - Progressively less bass. Female vocals are similar to the AC with that touch of crispness.

Grado Hemp w F-Cush - Much darker take on female vocals. Big boomy and bloomy mid-bass.

I think A/Bing between headphones is a little exhausting, but I find these type of reference points most helpful when imagining a new flavor of sound. The AC’s unique tuning didn’t overlap with anything I currently own. I’m happy to say it has dethroned the VC as my go-to closed back. The Caldera keeps its seat as my absolute favorite. As it should.

Caldera copy.jpg


For me the AC has the most agreeable tuning out of all the various closed backs I’ve tried. The Verité remains a worthy top tier player, but for those like me with presence sensitives, I’d like to extend an Italian olive wood branch. The AC pulls off a balanced sound profile and adds excitement on the top and bottom end. This fun bass-centric character is going to make the Atrium Closed a lot people’s favorite ZMF closed or open. At least until the Caldera Closed jumps into the ring.

Thanks Zach and ZMF for not resting on your laurels. Speaking of that – don’t sleep on this delicious Italian Olive Wood Ltd.

Atrium Laurels.jpg

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I don't own a VO so I can't do a direct head-to-head. I think the Atrium Open sounds a bit more tonally natural, but you do take a small hit on resolution and speed for sure. The beryllium driver just has a different sound to it. Not better or worse in the least. If you really love your VC maybe do go for an open option like the AO.

The Caldera is simply amazing. It sounds like a planar if you're ok with that. The jump in resolution isn't going to blow your mind stepping up to the Caldera, but it in some ways is like going between a LCD with very realistic color representation and a super rich OLED. I can't get enough of either of them.
gorgeous photography throughout the review, well done!
I have the LCD-X now as well and have to EQ so I'm sure it's a welcome Visual and auditory step up


100+ Head-Fier
Zmf Atrium Closed: the most spacious and natural sounding Zmf closed back to date!
Pros: -Natural, Spacious, and Musical
-A bass first type of sound that is physical, full, and at times thunderous!
-Light weight and comfortable
-Pad rolling to further tune the sound to your preferences
-Consistent in its sound characteristics across a wide variety of gear. Meaning its not amp picky.
Cons: -$2,400 is the price you pay for this unique sound and experience
-Some may prefer a less relaxed sound
-Might not be the kind of bass you want as some might prefer a thinner, tighter bass instead
Atrium Closed Review


Ao atrium open
Ac atrium closed
Ek Eikon
Vo verite open
Vc verite closed

Disclaimer: the following review is using a demo unit from Zach of Zmf. I have had no contact or conversation with him regarding my thoughts and opinions of this product. I will be describing the sound as well as comparing them to every other original zmf closed back and to my es labs es-r10. For this review I used the following gear: Moon River 2, Cfa3, Schiit Folkvangr, Sony ta-zh1es, Audeze King mk2, and a Berkley Reference Series Dac.

The Atrium closed (Ac) is a closed back dynamic headphone as part of Zmfs flagship line priced at $2,400. A line of headphones which seems to keep expanding with an open and closed counterpart. It seems a caldera closed is inevitable. To me though a zmf with the added word closed does not exactly mean a one-to-one translation of the open back counterpart. A closed back version to me is more a closed back that captures the general idea of its open counterpart but then changes things up to ultimately be its own thing.

The Ac is a 300ohm headphone using a bio-cellulose driver. Other zmfs that use this kind of driver include Auteur, Eikon (Ek) and Atrium which is the open back counterpart that will be referred to over this review as the Atrium open or Ao. This driver has been found in many dynamic driver headphones over the years giving a very natural timbre that I have not found replicated well by headphones not using this driver.

The Ac also uses the Atrium Dampening system which you can read about on the zmf website. On previous zmfs before the Ao, zmfs took more inspiration from guitars and the different cups influenced the sound in way that created a small but noticeable amount of variances between units of the same model to my ears. Even though I was able to hear these small differences, zmf headphones have always been made to match the targeted sound as intended for each model above all else and these wood cup differences are merely a minutia in the grand scheme of things. While different wood cups still influence the sound to my ears, the dampening system is playing a role that assists in creating a new control factor to help shape the sound in a more precise way. That is, Zach can now influence and shape the sound of his headphones to a more exacting degree which aids him in reaching his goals. For me, zmfs that do use this dampening system have less resonances in the sound. The inspiration of guitars continues even with the dampening system in that zmf headphones are not made to be solely reliant on their drivers alone or a specific innovation, but like a guitar is about how all the parts come together. In my personal experience, no part of the zmf headphone is ever just thrown together to simply look aesthetically pleasing, every part plays a role in creating a unique sound that undergoes rigorous testing before being sent off to its new owner.

In terms of looks, it is a zmf... so you already know it's very nice to look at and feels to be made of quality parts. It looks and feels better built than headphones costing substantially more money to me. The Ac that I have is using cherrywood and when I first held it in my hand it was not its light weight that hit me first, but the realization that this is the first time I have ever held a zmf using a stock wood as all my purchases of this brand whether new or second hand were of limited run variants using exotic woods. The wood is smooth to the touch and the finish on it makes it look special. Personally, for a stock wood I was expecting a rougher around the edges feel or something less in quality from my time with various limited woods, but I will admit that it seems zmf is very consistent with creating headphones that all look and feel equally nice. Unfortunately, I am not a professional photographer, so if you want to gander at the looks, go watch a b-roll on YouTube.

In terms of fit, comfort and design the Ac out of all the zmf closed backs are the least likely to create a hotspot on my head and the least amount of sweat around my ears. The clamp is never loose but not painfully tight and if it is too clampy, zmf has a video showing how I could bend the headband. The headband uses the crescent strap which is my favorite headband on any headphone as it is very comfortable and prevents a hotspot on my head.

The pads are very unusual for a closed back in that they are perforated on the outside and solid on the inside. Apparently, the pads are the Caldera thin leather pads. Pads on all previous zmfs are not only solid but also thick which I felt helped with the staging width, but while the Caldera pads are on the thin side, the Ac sounds the open of any zmf closed back I’ve heard.

Another thing is that the Ac has only one small vent on the back of the cups like the Vc. The Atticus and Ek have 5 vents on the cups. The Ac while it does not have cups that stick out as far as let us say a Sony or Es Labs r10, the Ac does have the most angular cup for a zmf in that the pointed outward tip peaks the furthest back of the cup vs the Vc which has an outward angle that does not peek out as far back. In my view the angular cups and perforated pads seem to be trying to help with the Ac's sense of space and further help shape and control the sound.

Sound Structure
Overall, it has a laidback neutral sound that is largely euphonic and sweet to my ears, so keep that in mind when reading each section.

Despite using partly perforated pads, the bass is most present part of the sound to my ears. While I myself have in past comments said there is a roll off in the subbass on the Ao, I never meant such comments as a bad thing as the Ao midbass hump lends itself well to how it plays bass from natural real instruments but not so ideal for artificial sounds from edm or rap music to my ears. The Ac tries to rectify some of this but not entirely in a way that I had expected. The bass while containing more subbass and impact than Ao, is not the same sense of impact as some previous zmf closed backs. The concern about its bass for me relates to its transient response. Sure, a headphone can have a large quantity of something in its sound, but how I end up feeling about that quantity to me is affected by transient effects. If the bass to me is crispy, quick, and tight I tend to feel the sense of impact and slam in a way that I usually associate with more traditional headphones. Now while the Ac can sound big and impactful, compared to other zmf closed backs, it acts to my ears with a duller sense of transient aggression that I get from lets say the Vc. That said, there is a fullness that triggered a big smile on my face as my favorite closed back headphone ever is actually the zmf Atticus. The Ac has this fullness and density in its bass impact that is more musical to me than most other closed back that I’ve heard. This musicality and sense of weight is great for those that want something bassy but wanted to listen to it for longer periods of time before feeling fatigued. I think however this kind of bass might also cause some controversy as there are a lot of audiophile critics out there that don’t think highly of midbass humps and this amount of subbass rumble. Keep in mind that if the bass is too much for you at first the caldera suede pads will help reduce the bass.

Personally, I feel that folks who have bass head tendencies like myself don’t get catered to enough on the high end. A lot of bass head headphones we go to are usually under $2k like those from using drives from fostex. For a bassy experience I have tried the following outside of zmf, the Fostex th900 mk2, Klipsch hp3, lcd 4, and the abyss 1266 phi tc and yet I sold all of them because I preferred the Atticus. I would literally go months without listening to these other headphones, some of them representing some of the best in the hobby, but no matter how much money I sunk trying to get these other headphones to work, the Atticus hogged my attention with little to no effort needed on system matching. This is not a knock on those other headphones as they all have their own fantastic unique takes on sound, it’s just that the Atticus was ultimately better at matching my preferences for a bassy experience.

Now before others jump to conclusions about the usefulness of bass that sounds a little duller in impact compared to other zmf closed backs let me explain a little more about my view on this. Regardless if we are talking about the Ao or Ac, they are both very easy to listen to. The controlling of resonances and cup reflections made possible by its dampening system along with their tunings leads to-for me-a very pleasing experience that can capture a lot of texture and can flex in a way that it is not consistently heavy on bass. That is, if I were to listen to classical or other instrumental music in general, the Ac can reflect a wide range of dynamic nuances in the bass that much cheaper headphones imo can’t quite capture, it is most certainly not a one note loud/muddy bass headphone, far from it. I think even with the stock lambskin pads, the Ac executes a tasteful take on bass that rewards listeners who want more bass, but not in a way that truly overwhelms the other frequencies to my ears.

In a closed back form, the Ac snaps more and punches harder than Ao but even when using stock lambskin pads this just doesn't go on the offensive to me the same way the Ek and Vc do. I am at ease even with heavy bassy music. Now I think that for a lot of other listeners, this will be plenty of bass for those who want more than what a recording would provide on its own and by having this added emphasis you get to add more fun to your music. I think for a lot of modern listeners who want more wobbly phat bass, this is actually a very good take on it.

This type of bass like the Ao also plays very well with realistic drums as the bass from an orchestra or a bass guitar or a kick drum are so very present and very physical sounding. I can also very much feel the kickdrum in a heavy metal recording to about thunderous levels and it appears very physical even for a dynamic headphone that is very sweet sounding to my ears. So, you can hear a strong bass line, but it will not try to murder your ears in its take on attack. I can understand other having to take their time with the Ac’s take on bass, but folks like me that enjoy the Atticus, I clicked right away. While this does add more subbass than Ao, I do appreciate the push toward raising the midbass over subbass.

Trying to rock out to the Ac’s bass is like being on a message chair giving a shiatsu message. It never punches the same way as most zmf closed backs before but its take on bass is like a middle man between Ek and Atticus. On its own, the Ac's bass is the most present part of its sound to my ears. I think Zach took careful consideration in his approach to the Ac's bass to prevent it from being big in a way that on poorly executed headphones would be interpreted as overly phat and bloaty. While I prefer a bass with more tightness and zip from his open backs, getting this amount of fullness in a closed back is its own kind of fun. Overall, I would take the Ac’s version of bass any day of the week over headphones that typically try to achieve large amounts of bass by sacrificing other parts of its frequency response like that found in v shaped headphones. Its bass is rendered in a way that does not really mess with the accuracy found in its mid-range or treble. Think of Ac as a more opulent take on a bass head headphone. If you like bass that is big but will not punch your head off, the Ac is a great choice and gives a great amount of subbass rumble that reminds me of the Ek.

For the Ao the midrange is to me the star of the show. It is so full, present, and emotional and yet for the Ac, here's where things change up again. The midrange ends up taking a step back to let the bass get to the forefront. Now this to me is not the same as a v shape headphone. With v shape headphones, they can sound tonally off or nasally in the vocals. That is not the case with the Ac because the midrange to me is simply kept at a distance. This may be concerning at first because the beautiful realistic human vocals on the Ao are now kept at a small distance back on Ac, but the consolation is that the bass is not overpowering the midrange. Music on Ac images well enough that the bass never really swallows the mids, so I can still choose to focus my attention on the mids at my own leisure. This slightly distant midrange coupled with a smoother sound is the main reason I feel relaxed when generally listening to the Ac. Other zmfs closed backs have a more in your face vocal presence a lot of the time and can come of as having a bit more shout when compared to the Ac. Being a little smoother around the edges gives its own unique reward of taking your time with your music while being emotionally engaged. This headphone to me is great for when you come home from work, you feel exhausted and you just want to lie back and relax to your music. The mids have this euphony that will not murder your ears with aggressive bites or zings. This headphone using the bio-cellulose driver continues to bring an organic presence to the sound. Also, since it's pacing is kind of a goldilocks in speed-not too fast or too slow-and it’s so smooth to my ears, music goes down real easy for me. It has a very musical approach to its sounds. Horns never sound honky to me on the Ac. Imho many other headphones sound too aggressive with pianos and I think they do not always convey how I would like to hear it. Like the Ao, the Ac is fantastic with piano, having a good strike to them that still maintains a soft decay. Keyboard related instruments are my favorite on Ao and now also on Ac. Vocals are still very natural sounding, and I listen to more female vocalists on Ac vs more male vocalists on Ao. Not having full sounding vocals as close to me as Ao leads me to enjoying females vocal more.

The driver being dynamic and physical sounding helps in preventing this headphone from having a bored in an elevator type of sound that other clean sounding headphones can sometimes have. It is still engaging but not overtly aggressively so. The Ac is when compared to other headphones a bit more forgiving of painful digital noises that some poorly recorded music might have. If vocals on a track have sibilance with its "s" and "sh" sounds, the Ac is almost like a hazmat suit protecting me from the common associations that hearing sibilance leads to an annoying sting. I do not want to give the false impression this is a dull experience as it really isn't. Like the Ao, it is just friendly to the listener. Its mids still have an inviting presence. As I listen to it, I increasingly find myself bobbing my head and smiling. It is a very dynamic experience that does not want to truly punish the listener regardless of recording quality. It does not remove all the imperfections in bad recordings per se, but it does take away the focus of when an imperfection occurs and pushes away the fatiguing characteristics that might be associated with it very well in the bass and mids, but not so much in the treble.

The treble to me was also fantastic on Ao, having an even presence that is not overly strident or bright. For the Ao, I would say it sounded neutral but leaning at times a little dark but not like let us say Atticus. The Ac in wanting to be a little more exciting than Ao has a treble that to my ears has a bit more bite, a bit more splash that is not exactly as refined as Ao. On the plus side, this is still not a truly a bright take on treble. On the downside, while this headphone does not sound sharp, I sometimes feel cymbal hits are a little too splashy on the decay. Sounds in recordings that have terrible rings in them will be dulled in a way that will help you better enjoy music but it will not be erased. On other headphones when tracks are ringing and are too tizzy sounding it forces me to lower the volume which can affect my overall enjoyment of some music as I do not want to force myself to endure those effects at the cost of losing my hearing. The Ac helps with making it ok to listen at the volumes that I would normally want to be at without really being punished by potentially fatiguing offensive qualities, but I would stress not to get carried away with this new kind of freedom. Yes, I do raise the volume a bit more than on other zmf headphones because of the laidback musical sound, but only by a little. Don’t test your luck and push it toward dangerous levels simply because it is laid back and easy on the ears. So, from me to you please take care of your ears. Overall, the treble imo is great but is not the star of the show whether talking about the Ac or Ao. It takes a bit more risk than Ao, but does so to prevent things from being boring without having to punish you for it.

Soundstage and Imaging
In terms of soundstage, it is the most open sounding zmf closed back to me. Width while generally as wide as Vc, the Ac is the deepest sounding to me. The Ac also has the most sense of air which helps with the sense of space. The Ac carries the Ao’s idea of staging in a way that feels like a venue or a more complete room vs both verites which are like a front row seat performance trying to push the listeners face into the details. The Ac layers in way that along with the mids which are taking a step back makes it feel like I am a free-floating camera at the venue vs the Ao which seems like I am an actual spectator. The Ac images in a way that it is surprisingly easy to pick out where different sounds are located despite its bass first sound with added fullness. The staging is far more natural than the Vc which reminds me of a planar in its imaging.

Resolution/Detail and any other thoughts about general characteristics
The resolution and detail are not as forward as the Vc and at times the laidback nature almost had me thinking the Ek was very close to it, but upon closer listening to the Ac, the Ac is consistently ahead in resolution over more affordable zmf closebacks. The Vc has an edge in detail and resolution which I think is easily detectable as the Vc is more aggressive than Ac in trying to show off and is more in your face about things. For a $2,400 headphone on cheaper gear, you might feel that you might be losing a little bit in detail because of the fuller sound when compared to the Vc, and while the Atrium dampening system helps with layering things out clearly throughout the stage, sometimes I feel that smaller distant micro sounds lose a bit of intelligibility compared to the zmf verites in general. The Ac like the Ao have the most natural sound besides the Auteur and it does a great job of not really being amp picky to my ears as its sound is consistent when using different setups like the Ao and Atticus. I think most other zmfs are less forgiving in comparison to Ao, Ac and Atticus. If you do not like the Ac’s sound and think its too bassy and wanted to get something that sounds closer to the Ao, you can swap the pads to the Caldera Suede pads. The suede pads reduced the subbass and brought a bit more clarity. Personally, I don’t really pad swap my zmfs as I usually like using the stock pads and I preferred the Ac with the stock Caldera Lambskin pads overall. I would check the forums for any pad gurus and above all else, contact Zach if you wanted any pad suggestions.

Even though I have used other zmf’s as indicators of how I am interpreting the Ac sound, now we are going to do more direct one on one comparisons. The overarching pattern or theme between the Ac and other closed backs for me is how the Ac sounds using the atrium dampening system vs other headphones that rely more on cup reflections. The other most obvious pattern is having to lower the volume when I listen to each of the other closed backs after listening to the Ac.

Atrium closed compared to Eikon
We need to get what I think is the most important comparison out of the way first. The Ek has been discontinued for some time and I think some are looking at the Ac as their savior or perhaps an upgrade. Understand that while I may give hope to those who love the Ek, this is zmf we are talking about and Zach doesn’t really do direct upgrades with headphones he releases. For those who own or have heard other zmfs, after reading my descriptions on how the Ac conducts itself, you already know that it is noticeably different than other zmf headphones.

To my ears the Ek is the brightest zmf dynamic (I have not spent enough time with a caldera to have an opinion on how it compares). The Ek has this immediate pep to its step and has much sharper edges compared to the Ac. The rumble is very good between both, but since the Ac is not nearly as bright to my ears, the volume and shape of its bass seems to hit a little harder than the Ek while still presenting generally equal amounts of subbass rumbling effects. The Ek has a more even bass that seems to have a slight raise for subbass vs the Ac which tries to keep the subbass elevated but bump up the midbass a bit more instead. The Ek is like the feeling of drinking lemonade in that it perks me right up, feeling alert with eyes wide open vs the Ac which is more like hot coco and at times has me relaxed and almost dozing off at times. The Ek is also the least forgiving zmf to my ears. Imperfections in poorly recorded tracks will be way more forward than the Ac. Cymbal splashes are more pronounced and a bit rougher in decay vs how the Ac does it. Even though the Ac is splashier than the Ao it does not crash with the forwardness of the Ek. The Ac is on the more neutral side when compared to the Ek, so the Ac is not necessarily a direct upgrade. The midrange of the Ek is also not taking a step back like the Ac and so vocals are closer to my face. Instruments like wind and strings are more present on Ek vs the Ac.

On a technical level, the Ac is much cleaner sounding and the individual sounds are better isolated as opposed to the Ek that resonates more and sounds a bit rougher on the decay. The Ac is more controlling of its presentation and shows a more seamless sound vs Ek that is more exciting to me. Ek is more recording honest like a studio monitor with added lush textures while the Ac is a downward slope that wants the listener to sink into a more musical approach with its relaxed sound while still being relatively neutral. I think that between these two Ek owners will have to do some soul searching and think about how they currently feel about their own Ek. Do you wish it was less bright? Maybe more forgiving and more relaxed about itself. If you really want a flagship zmf dynamic headphone that tries to emphasize subbass fullness like the Ek, the Ac will get you there better than a Vc imo. For me, I like owning every zmf model that gets released and I simply could not replace my Ek with an Ac as they are just not the same. I like to nickname the Ek a dark horse to me as I usually do not listen to headphones with lots of subbass rumble preferring more midbass punch, but the Ek is very infectious and I can get lost listening to it all over again whenever I pull them out.

Atrium closed compared to the Atticus
This was interesting as both Ac and Atticus are both downward sloping headphones to my ears, and yet Atticus is still the warmest zmf. Yes, the resolution is less than any other zmf closed back, but this is my second favorite headphone overall right after the zmf Aeolus and as of this review is still my favorite closed back headphone. This is my ideal take on warmth that like my love for the zmf Aeolus, I have been unable to find a headphone that can do what this does but better and no matter how much better a more expensive headphone can be, I have this huge preference for the Atticus. The Ac is more spacious vs the Atticus which has an overall more intimate presentation. Even though the Atticus lets me know subbass exists, it’s really about the midbass hump. The Ac tries to split the difference between the Ek and Atticus as it has more subbass presence and therefore more subbass body, but the Atticus hits harder than Ac while still being very musical and full sounding. In fact, while the Ac is musical, the Atticus to my ears is even more musical at times at the cost of detail.

The Atticus really goes all in on the fun while the Ac in its own way wants to be taken a little more seriously despite the musical bassy sound. The treble is not relaxed on the Atticus but comes off as a bit dark creating a more closed off sound as expected being a closed back, but the Ac is trying to be the most open sounding and spacious zmf closed back. They are opposites in technical performances in that while the Atticus keeps itself together well, the Ac wants to show off how things image and layer. The midrange on Atticus still feels like its more present than Ac but won’t nail the bump up in resolution the Ac can do. Vocals are more seductive and warmer to me on Atticus. Yes the Ac is a more realistic rendition of vocals using the bio-cellulose driver, but for my personal preferences, I never hesitate to choose the Atticus. The Ac makes a good compliment to my Atticus being of a similar downward slope but being more neutral vs Atticus being warmer. It’s nice to know that the Atticus is no longer alone in how musical it is.

Atrium Closed compared to Verite Closed
Between the two flagship zmf closed backs the Vc shares some qualities with the Ek in that it is less forgiving and is more chain picky than Ac and Atticus. The Vc uses beryllium on its driver and is the fastest zmf closed back. It has a bit of w shape to my ears and tries to keep the mids mostly present with only the vocals taking a step back vs the Ac which lets the midrange in general take a step back. The Vc is the most incisive in its imaging and reminds me of a planar. The Vc really wants to show off how fast and detailed it is compared to other zmf closed backs and it is also the least natural sounding due to using beryllium when compared to other zmf closed backs but it is certainly not unnatural on its own. The Vc does not emphasize the beryllium quality the way a focal headphone would imo. Subbass is the thinnest to me on Vc but it’s still available as it does not roll off and it can be affected by music with boosted bass. The Vc’s bass punch is the cleanest punch of the zmf closed backs to my ears, but lacks the fullness in its punch when compared to Ac and Atticus. Vc can hit plenty but this is not a bassy headphone to me. While things image more naturally on Ac, the Vc is like a planar and is more artificial about cutting through the music to keep things separated. Using the cup reflections and resonances like other zmf closed backs without the dampening system, things feel more thrilling to me than the Ac. I really like its faster incisive punchy sound for edm and rap to my ears. For how they both show off depth, the Vc has bit of a hollow effect to help achieve depth and sense of scale vs the Ac that does a better job of showing some distance. The spaciousness of the Vc is great on its own, but the Ac shows a slightly cleaner stage as a result of removing more resonances with the dampening system. The Ac is a good compliment to each of the other zmf closedbacks depending on how you look at it.

Atrium Closed compared to the Es-labs Es-r10 (Sony r10 replica)
This is the comparison I’ve been most personally hyped about from when I heard the Ao, I felt it would make a great compliment to this one and it is a flagship closed back from zmf that like the es-r10 uses a bio-cellulose driver. Just as I have hoped for, they work incredibly well together. Literally a Ying Yang relationship trying to maximize what you can get from this kind of driver in completely opposite ways. Downward slope (Ac) meets upward slope (es-r10). Vintage design approach es-r10 meet a modern design approach Ac. The Es-r10 utilizes its angular larger shaped cups to create its unique sense of space, but the Ac does not need to be so large in cup design to sound spacious. The es-r10 uses its own foam and damping materials inside the cup to control resonances even though it still resonates more than every other closed back I have. The Ac uses a dampening system to keep resonances under a much stronger control.

While both have fantastic mids, the bass comes first on the Ac and the es-r10 is thinner than the Vc and brighter than the Ek. The es-r10 tries to make up for the subbass roll off with having a very snappy crispy bass punch, that along with its brighter sound works great with classical and rock music. The Ac on the other hand can complement this being more about bass kicks and subbass rumble and works better for metal and edm imo. The es-r10 like the Ek wakes me right up, while the Ac is far more mellow in comparison. The Vocals are so human and realistic sounding on both, but the es-r10 is still more resonant in decay. In overall soundstage size and this might cause some controversy when listening to classical music and musicals, the Ac on a number of recordings matched my es-r10’s overall sense of scale which really impressed me, but the cup reflections on the es-r10 allowed the image size to be a little bigger than the Ac and still reverberate more. The larger cups of the es-r10 does create a more consistent larger stage than Ac. In terms of speed and resolution they are both behind the Vc to me and have a solid middle of the road speed. While I felt the Vc was trading blows with my es-r10, I think the Ac is a more appropriate equal to the es-r10. The Ac is a bassy mellow contemporary headphone to my es-r10. If you are very strict about needing to have the brightness of the es-r10, the Ac is not trying to be that, but with the atrium dampening system, this headphone to me is able to match the es-r10’s free floating imaging and some of its unique treble qualities.

I think the Ac is one of the most natural sounding dynamic driver closed back headphones which ties itself with my es-r10 in many ways while offering a tuning that plays better with genres of music the es-r10 would not be ideal for. Sadly, the es-r10 has recently become out of stock on the es-labs website as they only had a limited stock of materials to make r10 replicas. It’s sad that some unique headphones have suffered from being limited in their release, but that’s not the case with the Ac. The Ac will not be held back by limited rare materials, or by being released deliberately in limited numbers. Zach has created a headphone that carries the best of what the bio-cellulose driver has to offer while giving it a tuning that will cater to the modern listener who craves an organic timbre with more bass. The Ac is not an r-10 replacement as their overall frequency responses and tuning are opposites, but if you cannot get an r10 whether that be an original or a replica, to my ears, the Ac is the closest you are probably going to get to some of its unique qualities without going into serious debt trying to buy someone else’s pair. Also, even though it’s not bright like my es-r10 in the treble the Ac still carried an uncanny semblance to the glass like crystal clear qualities of my es-r10. It just won’t be as bright as the r10. Unlike my es-r10 it seems Zach can better mass produce the Ac vs the r10 which followed a much stricter approach to constructing it. Zach doesn’t necessarily need to use the same wood to get his intended sound as the dampening system will help keep each one consistent with each other regardless of the wood used as I understood it from trying different woods with Ao’s I have previously owned.

Amp synergy
I won’t go into too much detail as the review is already long enough but will summarize it as being similar to the Ao and Atticus in that the Ac is consistent and not as picky on different systems as other zmf headphones. From something cheap like my moon river 2 to something expensive like the ampsandsound Agartha, the Ac sounds consistently fun. I will add that I preferred using the Verite Silver cable with everything I tried as it added a bit more zing and liveliness to the sound. Now while I know cables don’t make a world of difference, I really like the quality of life changes the Verite Silver cable brought as it also removed microphonics that I sometimes heard from the stock cable.

I think the more I listen to the Ac, the more it impresses me in what it can do. It’s the most euphonic sounding close back that I’ve personally heard beside the es-r10 and the tuning of the Ac better caters to the modern genres I listen to. It stands out among Zachs headphones as its own thing which still manages to surprise me and keep me coming back for more. Eventually I will buy an Atrium Closed for myself and hope that unlike other rare/unique wooden headphones before it, the Ac will have a long and successful run getting into the hands of as many owners as possible. In our hobby we can get very attached to certain headphones because they perhaps had a historically significant design, or perhaps they had a unique sound that some audiophiles hold onto for life. I think the Ac will definitely have a dedicated group of followers and while I think some audio critics might be turned off by its more bassy musical approach and use of sweetness and euphony; in the current market, the Ac doesn’t really have any competitors in what it tries to do imo. If you really end up loving its sound, you are probably not going to find an acceptable substitute or upgrade anywhere else.


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Really helpful review, thank you!

I am convinced now that owning the Verité Closed, Eikon, and Atrium Closed is an ideal combination for me. It also sounds like the cable loom I have will work well. Exciting!
Excellent review! The ZMF headphones remind me of finely crafted pieces of furniture. A work of art for one's ears. 😀


1000+ Head-Fier
ZMF Atrium Closed: Solid Air
Pros: --The Atrium Closed twist on the ZMF House Sound
--Nothing feels missing in the signature
--The sub bass
--The Craftsmanship
--Smooth but with detail and clarity
Cons: --At $2499 +, the price is very good compared to other TOTL Headphones but is still expensive.
--Sub bass may overwhelm some but suede pads should take care of that.
SOLID AIR! The ZMF Atrium Closed Back Headphone



(John Martyn): Hey, SLC thank you for bringing me out of my deep dark place in order to ask you some questions out of my curiosity about the new ZMF Atrium Closed Headphone. I know you have listened to my music obsessively and thank you for appreciating my art. Please start out by giving us a little background and foreground before you start this review.

SLC: Can do John. It is a pleasure to be around you! Please say hello to Beverley from me. I know you are still in contact.

The Atrium Closed I am reviewing is a demo unit provided on loan to me by ZMF. It is the stained Cherry version of the stock wood and has gold rods. The change in shimmer as you look from one side of the face to the other is mesmerizing. This one has a lot of hours on it as a demo and was at Canjam. I have owned every ZMF headphone and what I can say is that they are, as with each ZMF HP, unique in how they present the notes to my cerebral space. I have not heard the Eikon for 5 years but some Eikon images are brought out as well as Auteur feelings of joy. I can hear that lineage in the Atrium Closed.

Another winner for Zach and Bev the owners of ZMF Headphones! Beautiful stuff. I have obsessed on certain HPs and certain audio companies. Such as Vision Ears, Sennheiser, and Noble Audio. Each for different reasons. ZMF is among the companies I admire. I admire ZMF for what it is seeking to do and how it represents itself and how it takes care of its clients. It is obvious that Zach is passionate about music and how notes are conveyed. That comes across in each one of his Headphones.

Each ZMF HP brings something different to the table. It is not at all about one being better than the other. It is about personal preferences. That is how good each one is.

For reviews, as of late, I use a fictitious discombobulated interviewer that is the unique interviewer for that audio company. John Martyn is one of my musical heroes. In honor of JM I will bring him back to life and he will be the ZMF fictitious interviewer from now on. A discombobulated genius he was! The title for my review will be “Solid Air” which is the title of one of his songs and for me the sound of the Atrium closed represents solid air. Each question from JM will include a quote from one of his songs at the end of my response to his question.

The goal of my review is to be as informative as possible and make it entertaining for my sanity/pleasure and hopefully for your pleasure. I usually include in the review an interview with the creator of the audio product. JM did ask Zach a few questions out of curiosity for this review. They ran into each other recently at a pub near Zach’s house. John can be found in many pubs around the world!

Along with my impressions of the AC, I will also dive into comparisons with other HPs. This will include a close cousin and a sister of AC: the Verite Closed and the Atrium Open. That will allow the reader that has heard those get a cognitive and maybe visceral feeling of what the AC is like. I will throw in a comparison with the Dan Clark Audio Stealth for those that have heard the Stealth. If the reader has not heard any of the comparison HPs, at least it will give you an idea of differences between them and possible personal preference you might have.

“I’m going home hey, hey hey, over the hill”. JM



John, the evolution of your music is a pleasure to listen to. From your albums with your wife at the time, Beverley, up to Grace & Danger. I thank you.

JM: Well, thank you SLC but I am offended with “up to Grace & Danger.” That was 1979. I lived longer than that. Anyway, please tell me about the slant of the face of the Atrium Closed. That is all you seem to talk about late at night.

SLC: The slant. So sexy. Only pictures can convey the slant and how the AC slant compares to the Verite Closed slant. Oh the slant.

Here are a couple pictures of the face angle/slant of the AC compared to the VC face slant.

First picture is with VC on top as she prefers to be. Sorry about the intimate mini XLR 4 pin female housing shots.

The second picture shows the slant well with the VC Leopard wood spooning on our left.

“If I can’t be a peaceful man, I will be who I can” JM



John, the 80’s were not nice to the late 60s and 70s musicians. Synthesized drums and adding your drinking buddy Phil Collins into the mix for Grace and Danger says it all.

JM: Those were my sources at the time and the direction recorded music was going at the time and I was starting to go to the very dark side. On the topic of sources, what chain did you use for this review?

SLC: All my impressions will be with these setups: Khozmo passive pre + Ferrum OOR/Hypsos + Yggdrasil OG and Holo May KTE + Holo Bliss KTE.

I do have the Jotunheim 2 and Bifrost 2/64 at work but I was not able get a chance to listen to the Atrium Closed on that setup. Darn work always got in the way :) Something like Bifrost with Jot or any quality tube amp is all that anyone “needs” for ZMF HPs. The rest is audio illness overkill of which I am very guilty of and most of you reading this are guilty of or will be guilty of. Is all part of the hobby/addiction. That said ZMF HPs scale up well with quality amp power and of course react well to quality tube amps. The Caldera was the only ZMF HP I have owned that did not change as much with each setup. That is most likely because it is a planar HP versus with a dynamic driver in all other current ZMF Headphones. The Caldera does not require as much massive power as for example the Susvara or Stealth or Expanse. The Caldera played happy with everything I threw at it. Obviously with a non powerful DAP or dongle it was fine and enjoyable but did not shine as much as with a powerful transportable DAP or a quality 2ch or desktop amp/dac setup. That did make a big difference with the Caldera.

I would like to start my impressions by mentioning the sub bass of the AC. So visceral. I can feel it. Super textured. But does not take anything away from the rest of the signature. I am using just the leather pads for now. I will compare the leather and suede pads at some point. I have always ended up going back to stock pads over time on all my ZMF cans. I think Zach chooses the stock pad extremely well. I also just prefer the feel of leather on my head compared to suede. Just a personal preference though.

The sub bass stays away when not called for but when it is called for it shines. This is key so that the bass does not overwhelm when not needed. I am really into sub bass and the AC does it for me. It is like the HD600 sub bass vs the HD650 mid bass focus. Or the Eikon sub bass slant vs. the Aeolus mid bass focus. The AC tops all of those in texture and for lack of better words it has a next level maturity going on in the sub bass. It is not just a fun bass that gets boring after a bit. It is mature and draws me in to understand it more even after an extended 5 course date together at a French restaurant. That says a lot :)

“Now please won’t you, please won’t you bear it in mind for me” JM


Now that is all off our chest can you talk a bit about where I like to start and that is the top end?

SLC: Your favorite area JM! How is the Atrium closed on top?

It is a marvel what Zach has done in that I hear the top end as very present but…… I have written numerous times in the past that I have not heard a treble I did not like. In the case with the AC, I hear the treble as very present but in a good way. I usually do not focus on the treble. It is always part of the evening or morning pleasure but not a focus of the foreplay nor post-play. With AC I spend time focusing on the treble and hear the treble in a different way. I can feel the sticks hit the cymbal with texture. I can picture the actual softness or hardness at which the cymbals are contacted. “Music Delivery / Percussion” by Andrew Cyrille is a great album to discover and feel the texture of the treble with the AC. Rather impressive.

I am not hearing the treble as rolled off which adds to the feeling of staging for a closed back HP. I am hearing the presence of the treble but with no fatigue. The treble plays into a theme of the sound of the AC. The theme of resolution, detail retrieval and clarity but with musicality and non fatiguing smoothness.
I know I have had HPs with great top ends but this is the first one that has me looking up top as much as down low!

“Take a little look from the outside if you can” JM



And your favorite area SLC, the mid section?

SLC: Yes, those mids. What is life without them!

Mids are really important to me and play an important role in the overall signature of an IEM or HP that I look forward to listening to. I cannot handle when too much is focused down low or up top. The Atrium Closed has the sub bass that is a star and the treble that draws you in. But how is the core of the AC?

I am hearing mid-range of the AC as not forward nor recessed. The mids are right where they need to be. That had to be hard to achieve with such good sub bass and treble. I do hear female voices a little bit forward compared to male voices. I hear a tiny bump in the upper mids compared to the lower mids. My guess is that is because of the treble being well balanced from upper and lower treble as compared to the bass that has a sub bass slant. This sub bass slant probably takes a little away from the lower mids. Just a guess from what I hear in my head.

Nothing is scooped out of the core nor raised to a level of easy fatigue. The AC has smooth well textured mids that ask for your attention but do not demand it. I have been listening to trio jazz all morning with Sax being the main instrument (recent Charles Lloyd). I am extremely impressed with the amount of “realness” and “liveness” in the sax notes. The tonality is so good and with feeling/texture. The excellent texture of the notes will be a theme throughout this review.

As I mentioned before the resolution and clarity are still excellent despite the smoothness. It is not an overly warm smoothness but more of a detailed and textured smoothness. Great combo in my opinion. The natural decay of the notes do not add much color at all. They add a lot to the enjoyment.

“This is the beginning of forever” JM


According to you, my first 10 albums were the only good ones and those 10 defined my overall signature, can you talk about the overall signature of the AC?

SLC: 10 albums is 7 more than most excellent musicians ever create. 1967 to 1976 is an amazing run and you did that all while the demons were at the door.

The signature of the AC is a pleasure to discover. I do not look at frequency graphs. Due to a lack of those skills or mainly because I care about the frequency graph in my warped mind. The frequency graph in my head has the AC going far to the left and far to the right for a closed back HP. That could cause issues with not being able to touch the notes in the middle (the Oriolus Traillii IEM for example). This is not the case with the AC. I hear an amazing correct presence of sub bass on one end and very correct and present upper and lower treble. The magic sauce in my opinion is that Zach put in enough mid range so that the Left and Right ends of the stage do not dominate. No dominatrix with the AC.

Most of instruments and vocals in songs are in the mid range. The mids have to shine otherwise you have a one trick pony. The mids of all ZMF headphones in my opinion are always enjoyable whether it is a thicker warm HP or a more analytical ZMF HP. For me the vocals and instruments like the trumpet need to be what I hear well and with feeling. The AC does not disappoint with that. Some HPs are more about the bigger picture and the intellectual act of focusing on each part of the signature is not what it is about. With the AC it is super easy to focus on each part of the signature and it is an intellectual joy to do so. But it all comes together to make the overall experience smooth and pleasurable. That to me is what makes the AC special. It is smooth with detail and clarity but somehow all those separate parts come together as one. I attribute that to the world class texture of this headphone. The Atrium closed does not go so far with the detail and clarity to become a clinical HP. The AC still has feeling in its detailed notes. The ZMF house feeling is still there.

Speaking of feelings, an AC revelation hit me last night. The AC is not about just smoothness, not just about clarity and detail, the biggest win that is now hitting me is the actual feeling behind the notes I am hearing. This texture as I have already mentioned a few times. I hear the saxophone, the trumpet, the drums, the guitar, the bass, the vocals etc. with feeling. I can feel the notes of the instrument. That is coming to the forefront after many hours of focus time with AC. She has met my parents and now we are getting our first apartment together.

“Some people got a glass eye, some people got a window to watch”. JM



Yes, the demons did get me in the long run but the notes were always in my head. Tell me about the Atrium Closed notes Mr. SLC?

SLC: I know you love chocolate John so let me use chocolate as an analogy. And do you remember that time John at the chocolate bar in Dublin?

I describe notes as somewhere on the chocolate scale. For example the Verite closed to me is more about milk chocolate notes. A little thicker and a little longer decay. A smooth impactful taste. The notes of the AC are more in the dark chocolate range. They are more clear, and more fine with less decay/reverb but with a truckload of feeling in each note. Some HPs have thicker notes and the presentation is more about the big picture and then you have to look hard to figure out the different parts.
The AC has the fineness of dark chocolate. Each part is easier to decipher. Each flavor hits me first with amazing texture. Whether it be a hint of almond or caramel or a coffee flavor. But those distinct flavors can be put together if I want into the overall flavor of the dark chocolate. The trick of understanding dark chocolate is letting each flavor that hits the palate be experienced. It is about the individual parts first which make the whole of it a joy. The AC is like that with an added bonus of still being smooth and textured. Each very distinct flavor goes into my being and combines into one as I want and when I want. The AC notes are like that. The individual to the whole vs. the whole to the individual. The Gestalt of the AC is really good: Gestalt as in “the human brain will attempt to simplify and organize complex images or designs that consist of many elements, by subconsciously arranging the parts into an organized system that creates a whole, rather than just a series of disparate elements.” I referenced Gestalt in a review I did of the Vision Ears EXT. That was about the whole first and then the parts second. The AC is about the individual parts that lead into a wonderful whole.

How the notes are presented and the signature of the AC is what creates this beautiful Gestalt.

“You’ve been painting it blue, and you’ve been looking through solid air”. JM


I know one of your favorite test tracks is Cousin Dupree by Steely Dan. Sick song and sick name for a group by the way. Can you tell me about the Cousin of Atrium Closed, the Verite Closed?

SLC: yes, it is an odd song but very well recorded as were your 4th to 8th albums.

What a compliment to each other! I just mentioned the whole Gestalt thing of the individual parts into a whole and vice versa. Well the VC and AC really are Ying and Yang. I know the VC well. I have owned it in three different woods. The current version being Leopardwood. VC is about the whole first. The music is presented first as something you can sit back and enjoy as one. In an impactful way but as one first. The AC has the individual parts first that combine into the overall music in the brain. With VC you go to the music/notes or not. With the AC the notes/music come to you. You can decide to lean back and relax and enjoy the overall music or not. VC is to AC as HD650 is to HD600. VC is to AC as DCA Expanse is to DCA Stealth. VC is to AC as Atticus is to Eikon. VC is to AC as Aeolus is to Auteur.

Yes, VC has impactful notes but the notes are milk chocolate as I mentioned before. They are thicker and the decay is longer. The AC is the dark chocolate. The notes with the AC have a quicker decay for me but still with a lot of texture/feeling. But the flavor of both last long whether milk or dark. Just a different flavor.

When I compare the same song with AC then VC and back and forth the first thing I notice is how the bass in presented. Strong sub bass with the AC. Very strong when called for. The VC presents the same bass on the same song as more mid bass focused. The second thing I notice is that the timbre of female vocals are different. Not better or worse but different. It takes about a minute to adjust. The tonality of the instruments are similar.

The impact of the thicker notes of the VC also comes out right away when I go back and forth. The AC presents the same notes as more laid back and more lean. Lean as in a smoother way with the main feature being as I mentioned before the feeling of each note of the AC is outstanding.

These two closed back HPs do compliment each other well.

“She walked to the water and came back looking good and feeling fine”. JM



This allows me to transition to the sister of the Atrium Closed. That would be of course the Atrium Open.

SLC: “You're just like a sweet and simple sister to me” from May You Never. I love your lyrics John!

The timbre/tonality comes across as very similar which of course makes sense. The AO comes across as more relaxed even though I would not consider it a warm HP. To me it is a relaxed HP. The AC notes are more in front of me and intimate in comparison and to the left/right and back and fore notes of the AO. The AO notes are around me but are more chill about it. AO is more of a longer session sound vs. the more present notes of the AC. AC is still for longer sessions just not as long as AC. AO is there all around you and you become one with it. The AC due to the added intimacy always keeps you a little on your toes. Ready for a little lovin’.

The staging of the AO is wider and higher which is to be expected with an open back HP. They both have a staging that is around the head. AC has a more intimate of stage as mentioned before but pulls off a wide Left to Right stage due to the added sub bass (wow is it good) and a very tiny bit of added sparkle on top compared to the AO.

They share timbre but depart from there. Wonderfully but also financially annoying, the AO and AC can both exist in ones staple of HPs just like the AC and VC can. If you really like the timbre of the Atrium then the AC will provide added isolation of course, added intimacy, added fun and added sub bass. AO will add space, an even more balanced signature, and a limitless lack of fatigue for very long sessions.

The AO likes to hang out with you and chill. The AC is a pleasure to be with but does have more of the “hello, I am here for some lovin’” going on.

“Life, go easy on me, love, don’t pass me by”. JM



Pads and Impedance! Our mantra when we would go out in the old days. Talk about them SLC!

SLC: Yes, a little P & I! Got us far late at night.

I will compare the Caldera slim leather pads (stock for Atrium Closed) with the Caldera suede pads. As I mentioned at the start of this review, with each ZMF headphone I have used, I end up pad rolling and then sticking with the stock leather pad. There are three reasons for that. One is that I think Zach uses the stock pad for a reason. It seems to be the one he prefers for the sound he wants/likes. Second, I prefer the feel of leather over suede. Just a personal preference there. And third it does end up being the sound signature I prefer.

Pad rolling with ZMF HPS is like cable rolling with IEMs but pads are lot less expensive than IEM cables. Each pad adds a different flavor to the existing signature.

That said what do the suede pads do to the Atrium closed sound that I am so used to now? Overall what I hear is that the suede adds an added touch of smoothness. If you find the signature of the AC needs to be smoothed out more then try the suede pads. It feels like a smoothness filter was put on them when using the suede pads. Everything is toned down a bit. Nothing is lost just toned down. It is a great option to be able to tweak the sound.

Short aside on Low and High impedance with the Holo Bliss KTE Amplifier. With an IEM the difference is drastic. The Hi-Z setting is not a friend of the EE Odin for example. But with Lo-Z setting things sound like they should. With the AC HP I notice a smoothing out even further with Lo-Z. Too smooth for me. I prefer the Hi-Z setting. This might be because I have spent many hours on Hi-Z with AC already. The detail and bass are better with Hi-Z. The texture is so much better on Hi-Z.




My first 10 albums according to you (I did other great albums you know) were staples. A current closed back staple according to a lot of people, is the Dan Clark Audio Stealth. Compare it to the AC please.

SLC: Remember John, 10 albums is 10 more than most and 7 more than other great musicians.

With the Stealth there is a lighter contact of the notes. The notes are a little further away from me. The Stealth takes a few minutes to adjust to before the music sounds “right”. This happens with me with most planar HPs. There is a slight mind adjustment that needs to happen. Then all is good. The Stealth is a lot harder to drive than the AC.

The two share a lot in their signature. My theory is in order to add staging both have an added sub bass slant and an added tiny sparkle on top. They both have excellent clarity and detail. Both have notes that are not milk chocolate in nature but are of the dark chocolate variety i.e excellent texture.

As I stated already the Stealth has the music around me but a little further away. The AC notes are closer to me in my head and more intimate.
The Stealth is considered by some to be the best closed back headphone in the world. The fact that the AC competes extremely well with it says a lot.

When I go back and forth between the two the planar vs. DD difference becomes obvious. Again they share a lot with their dark chocolate signature but a quality DD has that “analogue” halo around the notes compared to a more “clinical” presence around the planar notes. Neither is better than the other. Just a different flavor of a very similar dark chocolate.


Interview with Zach Mehrbach, the creator of ZMF Headphones:

Despite their differences in signature, the tonality of the AO and AC are very similar in a wonderful way. That said, the Atrium Open uses an Acoustic Titan Mesh. How did this come about with the Atrium Open? And how did it come about not being used with the Atrium Closed?

ZM: The titan mesh we custom cut to get what I deem "the right" amount of treble. There was quite a bit of back and forth in the Atrium open to arrive at the spot where the peaks are in the most agree-able place for the greatest amount of people. With the Atrium Closed I did have it on for quite a while, but then when I switched to tuning with the Caldera pads enough of the front energy was dissipated slowly through the outer perforations to enable me to get rid of the titan mesh.

It will be interesting to see as I move forward if I end up needing the titan mesh on any Caldera pad tuned headphones, but overall the titan mesh is used as a non destructive to "other" frequencies mesh to enable a custom tuning to the users preference for treble/above 3 KHZ or so frequencies. I tune all of them to my taste but we offer different meshes on the site for different tastes. A number of users use the Atrium with a solid mesh and some with no mesh on them.

JM: Zach, I cannot get over the slant of the face of the AC. I keep looking at it and touching it. I feel like Narcissus in front of the pool. How did the slant come about and why is it a different slant compared to the Verite Closed? Were you watching French New Wave movies especially by Godard and you became inspired to add a slant with a sexy curve to it?

ZM: Ha I appreciate the auteur/new wave reference! Really I set out to make sure it looked as different as possible from the Verite Closed as I could make it while retaining the internal characteristics that helped make the Verite sound the way it did. I knew that with my closed designs I don't like to angle driver (not yet) due to it causing unpredictable back wave and response characteristics. So angling the cup to a greater extent made sense to get the right kind of decay that worked with the Atrium damping system and dissipation of energy/air flow.

Aside from that - I wanted more weird things to be included, like an inlet or "gulley" of sorts. But it turned out that was really really hard to sand and would've been inconsistent visually.

JM: I had a hard time keeping the passion for creating new art going. Especially as the demons visited me more often. How do you take a passion and turn it into a profession and still keep the passion?

ZM: I think there's such a gamut/divide between what it takes to run a good business, and make a good headphone. If anything running ZMF as a good business to keep our staff employed and be a good employer, has just made my appreciation for making and enjoying headphones even greater. I typically spend my "free" time working on the headphones when it's not business hours as a way to "wind down" from all the frustrating ins and outs of the business part of ZMF. I just love that part of "creating" and fortunately have been able to keep it separate from the rest of it. It's been more of a struggle as ZMF has gotten a little bigger, but I plan on trying to keep it that way!

JM: Thank you Zach for taking the time to allow me to interview you. I am glad I ran into you at your nearby pub!!



OK, SLC our time has come to part, I hope to interview you again in the not so distant future. And yes, 10 classics was a lot of albums. Can you give the reader a final note before we part ways?

SLC: I will see you in the future JM. You will be back. Thank you JM for making the trip to the States for this review. I appreciate your insightful questions and I have enjoyed many hours with your music!

ZMF has done it again. A work of art both visually and aurally! The lineage of the Eikon/Auteur is there but for me it is taken to another level of texture of the notes and overall presence around my head. It seems very hard to keep the stage open and the reverb away in a closed back headphone. ZMF does amazing open back HPs and somehow creates masterpieces with closed back headphones. The sibling of the Atrium closed, the Atrium Open, is a wonderful headphone in its own right. The Atrium closed shares the same timbre but the overall presentation is its own thing and for sure should be experienced by anyone that can experience it.

I tip my hat to ZMF!

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Wow, this review was truly in-depth, intense and a masterpiece....I really want the ACs and I'm gonna start saving up now and make the leap sooner than later!
Am I smoking crack or did you say that the VC has slower decay than the AC? If so that would appear to contradict common sense.
We both might be :) I better way to phrase it is that I here longer notes with the VC vs. AC. Milk chocolate vs. dark chocolate.


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