ZMF Compendium

It's no secret that we as SBAF like/love our ZMFs, both because @zach915m engages within the community and is a cool guy, and because the headphones he makes don't suck. Nowadays, ZMF has a headphone lineup expansive enough that it's worth putting together a compendium to have some general information and measurements in one place.

A few things are important to note when considering buying a ZMF. They are not studio-neutral; all of them have some degree of ZMF-ness; varying degrees of coloration of timbre, FR, richness in harmonics, and cup resonance play (yes, even the open models have this. Look at the CSD measurements on this site). The ZMF tuning emphasizes the lows, has a small high-mid/low-treble dip, and a rise in the mid-treble. Also, all ZMFs can be tuned to some extent by rolling some pads; that and the differences that wood makes will be discussed later on below. Thus, the notes here will be general notes on the headphone as a whole, not comprehensive on what is possible by rolling pads to taste.

Lastly, ZMFs are heavy. The lightest headphone is the stock Verite, which according to the ZMF website comes in at around 410-420 g, and they can go up and beyond 600 g. Keep this in mind if you don't have a bull neck.

Note that this is a work in progress: I'll add relevant links and work to making this a resource people can peruse. Also note that some of the closed-backs I've only spent brief auditions with at a meet. I'll be paraphrasing some other trusted impressions as well.

As of 2024, some of these headphones are out of production. These headphones will be denoted with an asterisk (*) next to their name. I chose to keep the relevant links here in the first post; however the spider chart that I made will not have these headphones on there. This is because the chart otherwise looks like a bird's nest of lines and is very difficult to read.

Index

1. Brief summaries and relevant links
2. Explanation of the effects of woods
3. About pads
4. Spider charts:
   1. Spider chart overview of the headphones
   2. @dematted spider chart
5. Amp Pairings

Closed-Backs:

Atrium Closed
Kind of like an Eikon+. A little less slamming and "wild" than the open Atrium, more relaxed and gentle. Still will give the goods when called upon though. Has some pretty wild bass rumble not unlike the old TH900, but unlike TH900 the Atrium Closed will not murder your ears with horrid treble.

Measurements and Subjective Impressions

Atticus
Bold, energetic, and lively. Tilted towards being warm, with a localized mid-bass hump. Resolve is at least on the level of the HD6x0; very good and scales well with better gear. The driver is actually quite nimble and fast; maybe not quite Focal-fast, but gets up and goes.

Measurements and Subjective Impressions

Bokeh
Somewhat V shaped, but don't mistake this for your "fun" V-shaped FR that eventually makes you want to drill your eardrums out after throwing the headphones out the window. More like a tasteful dip in the upper mids with a comeback in the mid treble, but overall tilted warm. Unique driver timbre, probably from the LCP material, and not really much ZMFness (lacks the traditional cup reverb), but a cohesive package. Also unique in that it uses 3.5mm connectors to the cups. Not the most resolving, but does a lot with what it does.

Measurements and Subjective Impressions

Eikon*
More even than the Atticus above in FR, but doesn't slam as hard and is noticeably slower. Has a noticeable dip from 2k-4k. Beautiful timbre, if a little laid-back and damped in nature. For a relaxed, gentle listen in comparison to Atticus, which is more lively and slamming.

Measurements and Subjective Impressions

Verite Closed
Exactly like the Verite, but closed and even more....Verite. If that makes no sense, just know it's the headphone that belts out its wood cup and internal cavity resonance the most out of all ZMF headphones. Just like the OG Verite, it's the fastest of all ZMFs; almost as fast as the Utopia (while also being just behind it in resolve). Just like its open sibling, polarizing, perhaps moreso.

Measurements
Subjective Impressions

Open-Backs:

Aeolus
Zach's attempt at making an Atticus open. Loses absolutely none of the liveliness of the Atticus. Can kind of be thought of as a HD650 that slams more, is more colored, and has more "flair" in its presentation. It's a bit different than other ZMFs in tuning: the bass hump is localized around the midbass and doesn't bleed into the mids. Clean-sounding, but still not quite fully open with cup resonance around 1k - 5k. To borrow an analogy from @Hands, a lot like seeing an OLED with all the naughty settings on.

Measurements
Subjective Impressions

Atrium
The most dynamic and explosive headphone in the lineup, although not quite as fast as Verite. Tied in resolve with Verite, just in a different way (Atrium reproduces sonic textures better, especially in percussion and bass). Driver sound is similar to Auteur but not as tubey or "rich." Just as worthy of TOTL status as Verite, but also probably more agreeable to the general public (for what it's worth, this is "ZMF neutral")

Measurements and Subjective Impressions

Auteur OG*
An open Eikon essentially, but has a much more even FR, and used to be the most neutral of all ZMFs (that title now goes to Auteur Classic). The small peak at 6k is below the bass, so think of it more as 'has a dip between 2k-5k.' Beautiful timbre, incredibly good microdynamics, but isn't the most slamming can; holds back and has restraint. Just like Eikon, isn't fast, but the Auteur is a touch more lively and the right amp can kick the driver into gear. Can be accused of a small-ish stage only a touch larger than HD650, but has good imaging.

Measurements
Subjective Impressions

Auteur Classic
Like a ZMF version of a HD600, or OG Focal Clear. The most neutral ZMF, and in many ways it's sonically in-between the Atrium and Verite. It has a touch of emphasis around 2-3k that make it sound a little bit mid-forward, but not annoying. Also loses the OG Auteur's "lush" timbre. No, it's not as resolving as the Atrium/Verite but it's no slouch in that department either.

Measurements and Subjective Impressions

Verite
Almost as fast and almost as resolving as the Utopia with rounded transients. Superb dynamics (especially micro) and driver control; tucks at the heartstrings. Largest stage of all ZMFs, with great layering abilities. One of the most colored; tilts dark with Universe pads, more neutral with Verite/BE2 pads. Coloration comes from timbre and cup resonance; definitely not neutral. Probably the most polarizing ZMF alongside the Verite Closed; seems that people either love it to death or rank it as one of their least favorites (I love mine).

Measurements
Subjective Impressions
Verite, Revisited

Planars:

Caldera
A polite planar that competes with the TOTL big boys. Caldera is almost as resolving as the Verite and Atrium, doesn't have funky planar timbre, and has tonality along the lines of the Auteur Classic. While not thunderous or super dynamic and explosive (at least out of the wrong amp; it needs the right amp), the Caldera impresses as more time is spent with it; the plankton shines through and so do its microdynamics.

Measurements and Subjective Impressions

 

About Woods

These "LTD woods;" are they worth it? What do they even do?

Before I continue explaining here, I'd like to make one point very clear. Different wood types will NOT change a headphone's character, nor its perceived FR. Decide on the headphone first, then after considering some of the points made here, decide whether or not you want a LTD wood or the stock wood.

All ZMFs have some degree of cup resonance as part of their sound. This can be seen in any of the measurement links referenced above in the CSDs as kind of a "ring" or lasting decay on some models. Different woods have different resonance and decay characteristics, and due to the cup resonance, this has an audible effect on the sound of the headphone itself. Think of it like pianos; the wood doesn't necessarily change the instrument itself, but pianos whose soundboards are made of denser woods have a different sound than the ones made from lighter woods, even though they're both recognizably still pianos.

Generally speaking, harder and denser woods (more janka if you will, although technically janka is another topic that is only correlated with density and not an end-all-be-all number) will sound a bit more immediate and have lesser decay. This is because denser woods tend to reflect more of the sound waves back immediately upon the wave hitting it. The inverse is true for softer woods; less immediacy, longer-lasting decay characteristics. Going back to the piano analogy, this is one of the main reasons why different woods have different sounds. Of course, woods with similar density may still have differing sonic characteristics due to other factors such as porosity and the resonance of the wood itself.

The difference in woods is definitely audible. @neogeosnk's Verite and my own cocobolo Verite had notable differences in sound. However, it's a subtle difference and not worth agonizing over; small enough that you would only notice with a direct A/B comparison of the same headphone made of two different woods. This being said, there is a possibility that a different wood will tilt a headphone more or less towards your prefernces. Despite that, my advice is buy the wood type because you like the way it looks, because let's be honest; you're likely not going to be able to try a whole bunch of different woods before you purchase. There's absolutely nothing wrong with spending a little more because you just love the aesthetics, and ultimately, the Aeolus you just bought will sound like an Aeolus even if they're made of different wood.

More information on woods can be found on Zach's site.

 

About Pads

It's well-documented that rolling pads can have effects that can be quite drastic. With ZMFs, rolling pads can lead to noticeable changes in FR, changes in staging and imaging characteristcs, and differences in perceived transient response and slam. The effect that each pad has isn't necessarily all documented, especially considering that ZMF has a TON of different pad options available; however, Zach is very helpful in emails and also has this handy chart below:



Also check out the ZMF site for pads here.

General Pad Rules:

1. Material matters. Suede pads sound brighter than their lambskin counterparts. For ZMFs, the order from darkest to brightest in their pad materials is cowhide -> lambskin -> suede -> protein.
2. Perforations affect sound by essentially creating a less tight seal. This will make the headphone feel more "airy" and make it less bassy. Unless you really know what you're doing, stick to perforations if your ZMF by default comes with perforated pads, and solid pads if it comes with solid pads by default.
3. Zach is not deaf. He also has probably tried almost all of the pads on his headphones. Don't be afraid to ask him questions if you really want to experiment with pads.

We also have this thread by @Vtory that documents the effects that rolling pads has on an Auteur Blackwood. Please note that the information in that thread, while very useful, does not necessarily universally translate to every ZMF. In other words, pad rolling affects different headphones in different ways.

Unless you're ready to go down a rabbit hole that's comparable to the tube rolling rabbit hole, I'd generally stick with what Zach recommends and then go from there.

 

Obviously, they're all heavy headphones. I don't think I can post the weight of each one though; the ZMF site doesn't have the weight listed for every single headphone on there.

 

One thing to add to the diagram above: while I generally prefer neutral headphones, I actually prefer the Universe pads across the board. The most neutral of the ZMFs is Auteur. The others all follow a similar ZMF house sound with emphasized lows, an upper mid / lower treble dip, and a small rise in the mid-treble.

What the "neutral" pads do is bring up the mid-treble (and upper mids / lower treble a bit). I dislike any sense of treble peakage, therefore it's universe pads for me across the board.

 

@ChaChaRealSmooth, some notes to add above if you agree:

Aeolus: The emphasis is the lows is a bit different from all other ZMFs. The bass hump is very well localized around the midbass and doesn't bleed into the mids. The tuning gives the appearance of having a cleaner sound. In addition, it's not quite a full open back. It's more semi-open and there is some intentional reverb play with the cups around 2kHz, which is toned down considerably in closed Atticus.

Closed Verite: The most unashamed in terms of the wood cup and internal cavity resonance play among the ZMF headphones. Also the fastest (along with Verite) driver. I thought the Aeolus and Atticus were fast dynamic drivers, until I heard the Verite.

 

Interestingly, I've liked the pads that are more "neutral." However, I dislike the suede pads. I ordered suede pads for my Auteur and suede Universe pads for my Verite, and I don't use them. Too much compromise in other sonic areas; I feel they dull the transients and make the sound drier. Lambskin all the way for me.

Granted, I listen to a stock Utopia and don't find it annoying in any part of the FR so....

 

Actually no, never tried it. Maybe I'll give it a try, but honestly I love the sound of the Auteur with the lambskin Auteur pads and have felt zero urge to experiment further.

If anything, your point only solidifies the idea that it may be worth for some people to order a few different sets of pads and try for themselves.

 

ZMF Headphones Comparison Chart:

@dematted edition: https://www.superbestaudiofriends.org/index.php?threads/zmf-compendium.9044/page-6#post-331024





*I want to make absolutely clear that this chart is only meant to compare the ZMF headphones against each other. The values given in this chart are strictly comparative in respect to ZMFs and are NOT absolute values/grades given to each headphone. In regards to the values themselves, I poured over the threads, looked at both the measurements and subjective experiences, took my own personal experiences, and did my best to grade them fairly. Feel free to give me feedback.

For those unfamiliar with any of the terms used in the chart, I advise perusing this thread. The terms there are not only applicable to understand the above chart, but are common terms used in this community.

The category "Degree of 'ZMF' Timbre" refers of how much the headphone has the ZMF house sound/has a coloration of timbre (its "ZMFness"). That might sound a bit silly, since all ZMFs have this house sound to a degree, and all transducers have their own timbre for better or worse. To use concrete examples in the ZMF line, the Auteur is the most neutral of all ZMFs in this regard; you can think of it as mostly a neutral timbre with hints of the ZMF sound. The Verite Closed is the most egregious offender here; it belts out cup resonance, is decidedly tilted dark, and has a richly colored timbre.

One might notice the conspicuous absence of a staging category. My thought is that stage in headphones is generally bad especially in comparison to a two-channel setup, with perhaps the sole exception of things like the Raal SR1a (although you could argue the SR1a isn't really a headphone). That being said, I feel none of Zach's headphones are bad in this regard, and yes, they do all stage differently. However, I already felt like a 6 variable spider chart was beginning to push the limits of legibility, and felt that a 7th would have been a bit much. Plus, the subjective impressions threads do a pretty good job of conveying how ears here hear these headphones.

Rather than a chart, here's the order in which I feel the ZMF lineup falls from most open/largest stage to most closed/intimate:

Verite = Verite Closed >= Atrium = Caldera = Auteur Classic > Aeolus => Atrium Classic = Bokeh > Atticus
​

Know that all of them are acceptable in the stage category and do not suffer from being 2 or 3 blob (which I find offensive).

What the chart also does not capture is how I hear their timbre as a whole and not just in terms of ZMF house sound. The Eikon and Auteur have, in my opinion, absolutely beautiful timbre; some of the best I've heard. I also find the Verite's timbre to be seductive, but it's richly colored and the furthest from neutral of all ZMFs.

TL;DR, the goal here was to create a strictly ZMF comparative chart that would contain a lot of the comparative technicalities at a glance, with the intent being that one would go peruse the relevant threads afterwards. Again, it's not meant to be taken in absolute terms.

Edit: The Caldera is a little hard to judge next to the dynamics because simply put, it's a planar and fundamentally sounds different in a lot of ways.

 

It would help, but I'd seriously hesitate on calling it night and day. Probably wouldn't change one's mind if one thinks of ZMF as being pretty heavy in the first place.

 

^F'ing awesome. Finally had a minute to review in detail and I am actually in full agreement with everything on that chart! It could be that we talk a lot about these things, hence attribute the same meaning to words. The only thing I would say is that not everyone will necessarily be able to take full advantage of the results, e.g. a non-resolving component chain, a dead-sounding amp a la JDS Atom x1 gain, Schiit Heresy x1 gain, etc.