ZMFheadphones Atrium Closed

When you go to a great restaurant and you are in the mood for beef, do you get the Beef Bourguignon, or do you get the Pan Roasted Hanger Steak? One is unctuous, soft and perfectly melds with the Mirepoix and Red Wine. The other is perfectly pan roasted in cast iron and finished with butter, thyme and garlic and then sliced into 1/4" slices always against the grain and served with a side of Arugula lightly dressed in lemon juice and olive oil to cut the richness of the meat. You are at a Michelin restaurant so you know that both dishes will be perfectly executed. That is how I think of the Atrium Closed and Verite Closed. Whichever I reach for I know I will get a headphone that I want to keep listening to for hours on end. Hard choice, I love both beef dishes. Just depends on my mood. That is what this review is about. How do you decide which ZMF dynamic closed back flagship you choose? If you have both, you are very lucky and this review will hopefully give you more thoughts about each headphones' attributes. If you can only afford one, then I hope this review will help you determine which is right for you.

As always, everything written comes from my own crazy mind. I have not been compensated for this review and it is my absolute pleasure to share with you all my thoughts about both headphones. Is it a face-off? NO! Just as the two beef dishes aren't a face off, they are a choice from a perfectly crafted menu cooked by a world class chef. The AC and VC are world class headphones crafted by a world class designer. Zach and I talk a lot about what he is trying to accomplish. What is interesting about our conversations, is that his philosophy is so close to what mine was as a top chef 20 yrs ago. All I wanted to do was make food that people liked eating. The ultimate complement, someone who comes back to see what has changed on my menu and what are they in the mood to try. I wanted them to be enthralled, to engage their senses with dishes that were seasonal, balanced and full of flavor and texture. Zach's philosophy is no different. He wants to create headphones that people want to listen to. Headphones that when you are listening to them you don't want to take them off, or if you have to, that you will want to reach for them as soon as you are able. So, when you have two TOTL dynamic flagships, which do you go for when you own them both? Or alternatively, how do you decide which of the two you want to purchase if you can only afford one of them? Tough questions... after all, we all work extremely hard for the money we make, and this is the ultimate discretionary hobby. Just as eating at a Michelin Restaurant is. People don't just pop into Noma, they are there for a reason, be it a celebration or the curious nature of what the best of the best are up to in the kitchen. The AC and VC are no different. And for me, my curious nature has led me down a path of owning both and having to make that decision when the mood strikes.

This review aims to answer these questions. And if you want to eat either some braised beef or a seared piece of steak while reading, I invite you to engage your palate while you are engaging your musical senses. After all, they have so many similarities it is hard to ignore.

System for Review:
Roon Nuc10
Meier Corda Soul MK2
Matrix 10th Anniversary X2 Pure
Mjolnir Pure BiPolar
Eddie Current Aficionado

The Beginning:
At first this review was supposed to be just about the Atrium Closed. Zach sent me the Stained Cherry and a B-Stock Olive with a touch of green dye in an effort to bring out the natural green hues of the olives and the tree.


I spent about 2 months with them and couldn't come to a decision for how I wanted to write the review. I was struggling with synergy and I was struggling with the right words. For those who know me, that isn't generally an issue for me. I can take 500 words just to say hello. I also already owned a Cherry AO and wanted something different for my AC than Cherry. And the Olive was struggling in my system. So, I sent them both back and asked if he would build me a Camphor Burl AC, since I have always loved that wood and have always wanted to own one. Lucky for me, he was about to release the summer of burl. So, I bought the below beauty and a month or so later it arrived at my doorstep.


I was finally getting somewhere. The mid density wood perfectly harmonized with my system and presented the perfect amount of decay and air. I was ready to write.

Then Zach reached out and told me he had procured some very rare Black and White Ebony wood and asked if he could make me a Verite Closed, since I had been telling him I felt a hole in my collection and that was the headphone that I wanted to plug in that hole. So, I bought the below VC and after another 6 weeks or so passed this beauty arrived...


Isn't that headphone spectacular? I sure thought so when it arrived. Not only is it beautiful, but the feel is to die for. I now had the two flagship closed backs I longed for but a serious problem. I couldn't write more than a couple thousand words without my hands going completely numb. I needed to re-train my hands and learn to keep the pain at bay. Well, today I can proudly write to my heart's content and I can finally give these headphones their due. So, I decided to write about both instead of just the Atrium Closed. As many reviews as there are about both headphones, I haven't seen a review discussing both. Let's get started...



The ZMF Package:
One of the best parts of receiving a brand new ZMF is what you get. You get the headphone, a seahorse case or wood box for an up charge, two sets of pads, and two cables. The spec chassis is aluminum, but you can upgrade to magnesium if you desire a lighter headphone. I recommend the magnesium with their heavier hard density wood headphones. Plus, you get your own personalized card certifying that the headphone is yours and info on which pads work best for each headphone along with a cloth for wiping them down. You are also able to buy an upgraded cable for a discount. However, only one upgraded cable per purchase since you are getting a discount on the cable. Personally, I am a copper nut. I love the sound of high quality Pure Ohno Cast Copper. I love the way the Copper allows more current through and ultimately gives you a fuller sound. ZMF's 2K Copper is one of the best you can buy. I also really enjoy T3 Litz Copper and feel it does a great job with both the AC and VC. For my AC, I got a pair of the thin Lambskin Perforated Pads and a pair of the thin suede Perforated Pads. For my VC, I got a pair of Auteur Solid Lambskins, and a pair of solid BE2s. I use the Lambskin's for my AC and the Auteur Solid Lambskins for my VC currently.

Pad Rolling:
One of the great experiences with Zach's headphones is rolling pads. You get to tune your headphone to your liking by changing the pads. Some work better than others with certain headphones, but it is fun to try different pads for different tunings. @heliosphann has a fantastic spreadsheet describing the sound and pad choices. He keeps updating his work, and you will find no better place to learn about ZMF's pad choices and how they affect the sound of the headphones.

The Atrium Closed Back:
The Atrium Closed is unchanged from its Open counterpart in that it has the same 50mm composite bio-cellulose diaphragm surrounded by N52 rare earth neodymium magnets and a 300 Ohm Impedance. The only difference is that the drivers are sitting a bit farther back in the cups than the Atrium Open.

One of the changes is how the ADS dampening system was deployed. It is extremely malleable and can be used in different ways to accommodate the driver and acoustical space. The key to this is what ZMF calls "Gradual Diffusion" meant to eliminate the potential for standing sound waves.

ZMF has used it in the AC to distance in such a way that it creates space between it and the driver that, combined with the asymmetrical cup structure, allows for better and a more natural type of sound wave diffusion.

They have also introduced a thinner Caldera pad in both lambskin and suede with a slight fluted design that gives a more open presentation and helps to further diffuse the sound with the dampening system for greater impact and space. This leads to a greater sense of air and decay that makes the Atrium sound simply lovely.

Sound:

The Atrium Closed is more powerful sounding than its sibling, with a greater sense of bass impact than the Open. At first listen, the Bass is without question the star of the show. It is big, fast and subtle with a nice mid bass hump that isn't so much that it takes away from the linearity of the basses natural character. However, the Atrium Closed's bass changes with different wood densities and with pad changes.

In the lighter woods the bass is a bit slower and the decay is longer. In the harder woods the bass is faster with greater linearity and impact. A great album to hear these differences is Gil Scot Heron's "Pieces of a Man"

"Lady Day and John Coltrane" is the perfect song to hear how the Atrium's bass impacts the funky lines of Gil Scot's melodies and poetry.

Another album that I spent a lot of time listening to while enjoying the Atrium closed was After Sunrise w/Mikaela Davis and their new album Circle Around The Sun. This album has a lot of texture, weight and incredible treble energy, especially the Title Song, "After Sunrise".

The Atrium closed handled the complexity of Mikaela's off-beats with equal aplomb to the down beats of Gil Scot Heron. Lastly I spent some time listening to Michael Kiwanuka's album Love and Hate.

The opening song "Cold Little Heart" is my 19yr olds favorite song on this album. It has everything in it. Incredible back vocals, ambience, air, powerful lead vocals and omnipresent organ and guitar twisting its way through the entire song. When the drums kick in, you are fully immersed and the Atrium Closed has me hanging on every note.

The Atrium Closed images extremely well, with the perfect amount of space between the instruments while maintaining a powerful mix of dynamic headroom when paired to a high quality amplifier. Most importantly, the Atrium Closed continues the Open's incredible sense of front to back depth and near perfect image specificity. This I can hear best when I listen to live albums that are patched straight out of the soundboard, like Goose's newest live performance Live at the Chateau Sessions Part 1.

When listening straight out of the soundboard you get to hear exactly what the band is hearing in a live setting. Their song "Borne" on this live recording is a 32 minute joy ride highlighting everything that I love about the Atrium Closed. Their new drummers ability to subtlety manage his kick drums with cymbals opens up the rhythm and allows the bass player to open up the pocket giving the guitar and piano/organ the ability to float above the melody while you are anchored to the Atrium Closed's agility and ability to handle complex musical passages. Due to the size of the stage in the midband, vocals can sound a smidge set back. But they aren't set back, the headphone just has such incredible depth the tuning is actually quite linear through the midband. The depth gives you the sense of vocals a little pushed back. They are not, they are exactly where they should be. I really love this headphone!

Frequency Response:
When comparing to its Open sibling, you will find that everything below 500hz is elevated in comparison. However, it is by no means overdone. It is just different and extremely impactful. It has no problem stretching down to 20hz with a greater emphasis between 40 and 60khz. This leads to greater bass impact overall. There is a bump in the 2k-4k region and then again it has some emphasis around 4k and 8k which gives the Atrium Closed a sparkle and air that I find quite enjoyable. It is also a bit flatter through the mid-band giving the Atrium Closed less timbral qualities that are as north of neutral as its Open brother, which doesn't make it sound as soft as the Atrium Open.

Wood Choices:
I have heard several different Atrium Closed Backs. From the Stained Cherry to the Camphor Burl to the Olive Wood and more than its Open sibling there is a definite change to the sound depending on the wood density. Essentially, the softer the wood the greater the decay and the slower it sounds, however slight. As you get into the harder woods the Atrium Closed becomes faster with less decay and air. There is no better, just different. What I have found is that I prefer the Atrium Closed with a mid-density wood which gives me the perfect amount of decay, air and speed. I feel it is the best of all worlds. The beauty is that you get to decide for yourself based on what ZMF is offering which you prefer. Do you want something a bit lighter with more decay and air, or do you want something a bit heavier, faster and tighter? Your choice, and the beauty is that whatever you choose, your Atrium Closed will be tuned the same.

The Verite Closed Back:
When I received my B&W Ebonies I felt like a kid in the candy store. I was so excited I could barely get them out of the box. I was slightly sweating, hands shaking and doing everything I could to get them on my head. The Verite Closed is equipped with a different driver from the Atrium and does not have the ADS dampening system. I asked Zach if he would ever try the ADS on the Verite and he said no. That he had this headphone exactly where he wanted it. There is no doubt this is the case as I believe it remains his most popular headphone.

The Verite Closed has a Vapor Deposed Beryllium Driver with 99 db/mw. It is also a 300 ohm headphone like the Atrium. This is an extremely fast driver and leads to a very different sound signature to the Atrium. It is more traditional in the sense that it doesn't have the astounding front to back depth of the Atrium, however it counters with incredible speed and fantastic timbral qualities that make the Verite Closed sound even more holographic.

When I put them on for the first time I couldn't help but smile. Of course, as I always do with a headphone I haven't either heard, or heard for a long time I go to albums I know and songs that help me to understand what I am listening to. So, I chose The Jerry Garcia Band from 1976 at the Orpheum in San Francisco. A now dead and gone theatre that hosted many a wonderful shows in its time. From Janis Joplin, to the Grateful Dead and Miles Davis.

Listening to Jerry play Jimmy Cliff's "Sitting In Limbo" and the JGB song "Mission in The Rain" not only brought me back to my formative years cooking in San Francisco, but the 1,000 plus concerts I was treated to living in such a music rich environment. The Verite's sonic capabilities are truly a treat. It is open sounding, although not to the level of the Atrium and has incredibly fast bass that leads into the midrange without any bleed or blend. The bass has no problem going down past 40khz and is extremely present in the 100-150khz region giving the Verite a full and romantic sound.

The midrange is my favorite part of the Verite Closed. It is full of air and although the stage doesn't present as big as the Atrium Closed, imaging is still spot on and gives you the feeling that each instrument is fully developed. So, while the stage isn't as big, there is more micro-detail and low level detail due to the speed and space that the drivers and cups give you. Vocals are perfectly in place, and so incredibly emotive and full of sweetness. No matter the musician, or the song I can hear the singer breath, and I can hear every aspect of their voices emotion and range.Vocals seem a bit mid-forward, but they are actually not. Just like the Atrium where vocals feel a bit pushed back due to the size of the stage, the opposite is true of the Verite. Vocals are exactly where they should be.

To test this even further I pulled out the Mark Knopfler and Emmy Lou Harris Live Album Real Live Roadrunning.

I put on "Romeo and Juliet" and sat back for the most enjoyable listen. Every instrument sounded exactly as it should. The piano had bite and decay, Knopfler's guitar had the perfect amount of twang, and his baritone voice was full of emotion and grit. This is one of my top 5 favorite songs, and this is my favorite version. The Verite Closed presented the recordings full essence. The type of sound that makes you want to keep listening. Just one more song, just one more song. Is there a better complement to a headphone.

This review is starting to get extremely long, and because the Verite Closed has been reviewed so many times, I am going to skip frequency response. I think what I've written thus far will give you a good idea of what this headphone is doing. I will say one more thing, though. The treble on the Verite Closed, while still possessing the ZMF downward sloping treble, has a node that I can hear around 5-6k and one around 8-9k that gives the headphone the perfect shimmer and really highlights the speed and benefits of a beryllium driver. The headphone just sings and has an incredible amount of weight and saturation, that with proper amplification becomes incredible top end resolution with a hint of wetness.

Amplifiers and Comparisons:
Eddie Current Aficionado: There is no winner here. Both the Atrium and Verite sound absolutely sublime on the Aficionado, especially when I roll in my 1932 RCA Single Plate 2A3s. There is a nuance, and wetness to the sound that makes both headphones sound absolutely perfect. There is no winner, just pure musical bliss. Whether I fix the X2 Pure's DAC, or leave it as adjustable to bring down its internal volume so that I can have more volume play on the Aficionado, the result is the same. Dynamic, emotive and full of brilliance. This is one special amp, and both headphones sound impeccable on it.


Mjolnir Pure BiPolar: I wasn't sure how this was gonna go. With my Atrium Open this is not my favorite pairing. It still sounds great, but not even close to how good it sounds on the Aficionado or Corda Soul as it doesn't have the ability to impedance match. My favorite headphone on this amp was the Verite Closed. The weight of the PB's midrange was a perfect match for the Verite Closed.


With the Verite Closed, the PB's pure speed and stable drift makes the headphone absolutely sing. It sounds every bit as good as it does on the Aficionado. The bass is fast and strong, and the midrange is open and articulate. The treble is a bit darker, but still a great listen.

With Atrium Closed, it was also wonderful, I just preferred the Verite. However, the Atrium's natural front to back depth and its already fabulous bass gave this pairing something special. I learned this most when I put on Widespread Panic's Acoustic Live Album Uber Cobra.

WSP does a version of the Talking Heads song "City of Dreams" that must be heard. It is so beautiful, and just drips with saturation and resolution. The PB and Verite take this classic song and bring it to life. A friend of mine said to me about this song, "there are just some songs that deserve to be played, deserve to preserved and deserve to be covered". John Bell's voice and John Keene's slide guitar take David Burn's classic and blow it out of the park. And the Verite Closed on the Pure BiPolar exemplify this as well as anything I've heard. It is a soundboard matrix, and the Verite makes me feel as if I am sitting on stage with the band listening as they play.

Meier Corda Soul MK2: Not much to say here other than that the Soul is an absolute perfect complement to both headphones. Having a 120ohm output gives you the ability to perfectly match the headphones to the amps best. I loved both headphones on the Soul. I am not sure what else to say. Bass, Midrange and Treble were all balanced. The instruments had the perfect amount of air and there is nothing missing in the music. The Soul set a perfect image and the Atrium and Verite were more than up to the task. The Soul's upgrade gives both headphones timbral qualities just north of neutral while providing every bit of micro and low level detail both headphones can muster.


Conclusion:
Owning a ZMF is like owning your own 1 of 1 headphone piece of art. Whether one or the other, or both doesn't matter. The biggest difference to me is the size of the stage and the fact that the ADS in the Atrium does a better job of creating front to back depth which gives vocals and other instruments a sense they are more pushed back, but what they have actually done is figure out how to separate near and far sounds. The Verite counters with speed, articulation and more saturation which gives you a different type of resolution. They are both incredible headphones with great properties that enables them to sound great on a lot of different amplifiers, and while they sound different, there is no mistaking that they are both ZMF's. I hear the same properties regardless of the amplifier, especially using really good amplification. They both have their own nuances, and their own special way with music, and what they do, they do extremely well. The rest just comes down to personal preferences. Bravo Zach! I am proud to own one of each. If you have to choose between them, go by your gut and know that whichever you choose you will not be disappointed. If you are lucky enough to own both, then you get to wrestle with which one you can't take off at the end of the night.

Introduction

I've been using the ZMF Atrium Closed (AC) headphones for about three and a half months this year. Below I share my thoughts on their sound quality, which I'll focus on rather than their design or specs that are already well-documented.

In brief, AC is the second-best pair of headphones ZMF has produced, representing their best-sounding electrodynamic model. AC excels in tonality and technical performance, as I elaborate on below. I'll aim to give an impartial analysis, but please note potential caveats my review may exhibit.

Before diving in, two aspects of my preferences are worth mentioning:

• I favor ZMF products, so cannot claim to be fully objective about them. I have great respect for Zach and his craft. Readers should be aware my assessments likely contain unintentional bias.
• I'm not a fan of midrange-heavy headphones. To me, perceived neutrality is a mildly v-shaped signature that elevates bass and treble. Consider this when interpreting my impressions.

My evaluation is based on using the AC with the following gear, all of which I'm very familiar with:

• DACs: SMSL M500 mk3, Gustard X18
• Amps: SMSL HO200, Topping LA90
• Comparison headphones: Dan Clark Audio Stealth, Hifiman Susvara, ZMF Caldera, HarmonicDyne Athena

Now onto the AC's standout sound. I’ll first talk about tonality then pivot to technicality.


Tonal Balance

ZMF headphones always excel in bass reproduction. The AC offers an ideal blend of low-end energy and extension. Below 500Hz, bass gradually elevates by 2-3dB per octave, aligning with my mild hearing loss in that region. Extension remains full down to 20Hz. The AC's bass is deep and textured yet delicate and uncongested. It contrasts the hard-hitting yet looser bass of the Atrium Open.

Some may consider the midrange a matter of taste; I find it well-balanced, especially with Caldera pads. A slight midrange dip suits my older ears by emphasizing bass and treble.

The AC's treble recalls qualities of the Verite and Eikon, skillfully blending their strengths. Upper mids gradually gain presence, and overall treble leans slightly aggressive. Some recordings may sound harsh or sibilant to certain listeners, but I haven't found the AC sibilant.



On Linda Lindas' "Growing Up" (2022), the AC showcase their mastery of tone. Vocals have solid fundamentals, kick drums pack a punch, and bass guitar has appropriate heft without losing richness. Snare drums have a softer yet defined bark, and the AC renders the laid-back, slightly cupped vocals engagingly. Despite minor flaws, the AC delivers a compelling listening experience.


Technical Performance

The AC has a smoothly colored timbre compared to the more realistic Atrium Open. Their presentation features slightly elongated note decay and generally non-aggressive delivery, suiting the delicate nature of the AC. While I enjoy this coloration, it may not appeal universally.

The soundstage is highly impressive, with minimal boxiness or cupped reverberation. Though marginally narrower and shallower than the Caldera, the AC provides one of the most spacious soundstages I've heard from a closed-back design. In fact, their stage nearly matches open-backed dynamics like the Verite.

Dynamics represent the AC's main limitation. While they resolve volume gradations and nuance well, macro-dynamics can sound slightly compressed. During climaxes in orchestral scores, the AC plays loudly but lacks some impact.



This strength and weakness comes through on Stravinsky Ballets conducted by Simon Rattle and the LSO. The AC may not match the Caldera's power, but still deliver a convincing and soulful performance. The texture of lower strings is easily discernible, but dense orchestration loses some clarity. Crescendos to tutti lack the desired heft and weight.



Similarly, on "Oster Peterson Meets Roy Hargrove," the AC showcase their talents along with shortcomings. I can still easily grasp the musical narrative like with the Caldera. Perhaps the piano is occasionally overshadowed by cymbal accents, but the balance between the spicy cymbals and rich piano remains excellent for an engaging listen.


Measurements

I encourage readers to carefully note several key points regarding my measurements.

• All the results below were taken with MiniDSP EARS.
• The frequency response has been compensated for a home-brew hybrid curve that is derived from several different profiles (mainly HPN and HEQ).
• The "ideal response" curve is overlaid with the product FR as a subjective neutral reference.
  • This response is derived from a weighted log-level average from several different products that I believe are tonally well-balanced in their own right: ZMF Caldera, DCA Stealth, HarmonicDyne Athena, HFM Susvara. Optimal weights were determined through randomized and programmed self-test iterations with flattened Stealth/Susvara.
  • As a result, I found multiple considerations (hearing loss, my usual listening level, equal loudness) have been factored in.
  • Please take the "ideal response" curve with a grain of salt due to its highly experimental nature (at least for now). No guarantee that it is also ideal for you unless there very similar common tastes.

Here are some highlights I found during my analyses.

• The overall frequency response aligns well with what I perceive as neutral for my typical listening volume.
• Bass extension is excellent, easily reaching down to 10Hz - uncommon for a dynamic headphone.
• There is subtle unevenness in the bass, likely due to internal resonance cancellations.
• The C-suede pads lift the midrange but significantly intensify the upper midrange. This did not work for me but may suit some listeners.
• The upper midrange is mildly emphasized, audibly but not negatively. The strong 8kHz peak seems less prominent in actual listening.
• Tonally, the AC are much closer to the Caldera than the Atrium Open within the ZMF lineup.
• The AC bears an interesting resemblance to the HarmonicDyne Athena. The key differences are in the upper midrange and treble regions, aligning with my subjective analysis.

Conclusion

In closing, the ZMF Atrium Closed represents another masterpiece from Zach and his team, demonstrating why he is regarded as one of the premier headphone designers. The Atrium Closed come tantalizingly close to the performance of the flagship Caldera, and stand as ZMF's best-sounding closed-back dynamic headphone yet. Their slightly dark, smooth, and refined sound suits those who favor rich texture over hyper-analytical detail. Despite some limitations in dynamics, the Atrium Closed excels in delivering superb tonal balance, outstanding soundstage size, and engaging musicality. For fans of the ZMF house sound, the Atrium Closed belongs on your short list for audition. Their combination of top-tier aesthetics, wearability, and sonics cement their place among the upper echelon of high-end audiophile headphones.

ZMF - WHEN YOU'RE HERE YOU'RE FAMILY

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.







PRECIOUS

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







LET IT BURN

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.







TRUSTED SOURCES

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.


IMPRESSIONS & CONFIRMATIONS

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.







3-BAND

TREBLE
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.

MID RANGE
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.

BASS
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.

EDIT:
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.


STAGE

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.





SEPARATION

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.


ISOLATION

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.







PAD SWAPING

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.







SPAGHETTI WESTERN

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.







CONCLUSIONE

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.

Ciao.