ZMF Aeolus Review

Zach Mehrbach is the closest thing the headphone world has to a rockstar. He is one of the most highly regarded engineers in the business – at audio shows, his stall is always heaving with fans wanting to check out his latest creation. His company is ZMF Headphones, which he runs with his wife, Bevin, and they recently sent us one of their new models to test out. The new Aeolus. In this review, we break down the concept, sound, design, packaging and accessories, specs and more of the ZMF Aeolus. To see how they stack up, check out our list of the best high-end headphones.
 

Concept

You are not going to get the ZMF Aeolus on Amazon Prime. You couldn’t get them if you bribed Jeff Bezos himself. You are almost certainly going to have to wait a few months - possibly many months - after you place your order before you actually receive them. Part of what makes ZMF so special, and so highly regarded, is the way Zach and Bevin make you wait. It’s the most pleasurable, infuriating, agonizing wait in the history of audio gear.

To be fair, they don’t do it to be malicious. Every single pair of ZMF headphones is made by hand, out of a wide selection of beautiful and sometimes very rare woods. This process, understandably, takes a long time. It’s the complete antithesis of a pair of plasticky headphones churned out by the thousands in a factory. In their Chicago, Illinois factory, ZMF will custom-make your dream pair of cans quite literally from scratch.

The idea behind the Aeolus was to create an open-back version of ZMF’s legendary Atticus - a closed-back pair that was and still is renowned for its thundering, riotous sub-bass. You can buy a pair for around $1,200 in the stock sapele wood, but Zach will make you a pair in just about any wood you like.

Headphone obsessives often talk about the concept of the Endgame – that mythical combination of amp, DAC, cables and headphones that will be the last collection of gear they will ever need to buy, and will satisfy them for the rest of their lives. Nobody has run the numbers on this, but we’d bet there’s a strong correlation between the number of forum posts tagged Endgame and the appearance of a pair of ZMFs. It’s not just how they sound – and as we’ll show in a moment, they sound terrific - but it’s how they focus every pair of eyes in the room. They defy the idea that audio gear needs to be functional, bland, or ugly. They are a middle finger up to every black-box A/V receiver and bulky amp and crappy mass-made pair of headphones you’ve ever seen. They are objects of beauty – really, it isn’t too strong to call them this. If you look after them, they will almost certainly survive you, in the same way a fine piece of furniture or a well-seasoned cast-iron pan will. Hearing a pair is an absolute joy.

ZMF stands for Zach Mehrbach Films. He once wanted to be a director and ended up keeping the name when he began building headphones. Is it any wonder that a man who once had the ambition to make movies has created something that attracts so many eyeballs?

Sound

Midrange

Spoiler alert: we adored the sound of the Aeolus. We’d be crazy not to. It’s so well constructed, so effortless, that it truly left us in awe – again, not too strong a word. The entire experience of listening to these headphones was an absolute joy, and it all starts in the mids. They are truly glorious, presenting the kind of confident, assured picture that other manufacturers only wish they could achieve. Vocals – and female vocals in particular – all but leap out of the headphones, dazzling you with their energy and presence. If you listen to genres that are heavy on the vocals, like acoustic, folk, or pop, then you’re going to be in heaven here. The mark of a good pair of headphones is always when we find ourselves going back through our favorite albums, trawling the depths of our memory, pulling out songs we thought we knew back to front just so we could listen to them fresh. The Aeolus may have the objective of being a new version of the Atticus, but the stunning mids carve out a space for themselves all on their own.

We genuinely don’t think there are any other headphones in this particular price range that can beat the Aeolus for impactful mids. Take, for example, the $1,498 Focal Clear (full review here). To be clear, we love these particular Focals. They remain one of our favorite pairs of headphones, a pair we were genuinely excited to have in the office, and genuinely sad to send back to the manufacturer when we were done reviewing them. They offer sweet, clean, balanced sound quality. But up against the Aeolus? This quirky, less-expensive, hand-made darling? There’s no contest. The Focal Clear are great; the ZMF Aeolus are spectacular.

We also found the Aeolus to be incredibly speedy headphones. If you’re unfamiliar with the world of high-end audio – and good for you, because it’s a freaking rabbit hole – to call a pair of headphones speedy or fast means that they deliver a high degree of accuracy in the sound. Essentially, the quicker a pair of headphones can get a particular sound to your ears, the less that sound decays or is fundamentally changed in its passage. It’s actually quite tough for headphones to pull this off well, but the Aeolus nail it. Nothing felt bloated or congested; everything was clean and clear.

Low-End (Bass)

You shouldn’t go into the Aeolus experience – and that really is what it feels like, and experience – expecting mass amounts of bass. The Atticus model that the Aeolus is based on was renowned for its huge sub-bass slam, with a deep extension into the low-end that remains incredibly satisfying, like rolling a piece of really dark chocolate around your mouth. The Aeolus doesn’t quite deliver the same experience, but that’s a good thing.

There’s still plenty of bass, but they emphasize control over power. They are far more dominant in the mid-bass than the sub-bass, meaning you get the energy and punch of a kick drum, rather than the almost subsonic boom. We often talk about headphones as being darker or lighter, which is really just a way of saying that they are more dominant in the bass or the treble. There are plenty of headphones that are darker than the Aeolus – cans like the AUDEZE LCD2C (full review here) come to mind - but they managed to strike a good balance of dark, textured bass and delightful energy. If there’s one element that’s going to split opinions about these headphones, it’s the fact that they don’t deliver the bass of the Atticus. But we adored the Aeolus and how well the bass meshed with the overall sound quality.

High-End (Treble)

We aren’t the first people to talk up the midrange of the Aeolus – hell, land on any audio forum, and it’s often one of the first things people comment on. So we weren’t exactly surprised when the mids were so good. What did surprise us, perhaps more than anything, was the quality of the high-end. It was a lot more adventurous than we would have thought, refusing to play in the background, giving us a clear and complete picture of what was going on. Symbols sizzled, violins seemed to stretch into infinity, and the level of detail was terrific.

Up until now, we’ve always thought that the best headphones were made by companies like Sennheiser. The Sennheiser HD650s, for example, had previously impressed us with their excellent, neutral, balanced treble. Compared to the Aeolus, however, they sound weedy and thin, with not nearly enough energy. Admittedly, they are significantly less expensive than the Aeolus, but even compared to pricier models, like the HD800s, the difference is dramatic.

We have this thing we do sometimes at TMS; we call it the Friend Test. We have a friend, who shall remain nameless, who wouldn’t know a good pair of headphones if their logo was tattooed on his body. He’s a wonderful guy, but he’s a philistine of the highest order. We once gave him a pair of $3,999 Focal Utopia (full review here) to listen to – and even if you know nothing about audio, as he does, it is immediately obvious that something special is going on when you listen to those headphones. His reaction? Nothing. Nada. He said they were “nice”, which so infuriated us that we almost unfriended him on Facebook. Well, we tried the Friend Test with the Aeolus. On paper, we should have gotten the same reaction – the ZMF headphones are significantly less high-end than the Utopia. But you know what happened? A stunned, satisfied smile. Gentle head nodding. Dancing eyebrows. The Aeolus pass the Friend Test – and we genuinely can’t think of another pair of headphones that has.

Soundstage

The Aeolus use dynamic drivers. These are, by far, the most common type of headphone drivers in existence, appearing in virtually every pair of mass-market cans out there. They usually tend to be less expressive, especially in terms of soundstage, than the more high-end planar magnetic driver type – here’s more if you are interested. But Mehrbach typically doesn’t deal in planars, so dynamic it is. And as you’d expect from a pair of open-backs, the stereo spread is magnificent.

To be fair, the Aeolus are building on a solid foundation. The Atticus are closed-back cans, but they present a surprisingly wide and deep soundstage, with instruments coming from all around you. The Aeolus double down on that. They aren’t the widest headphones we’ve ever heard – that honor goes to the pretty spectacular Meze Audio Empyrean. They aren’t even as wide as other models in the ZMF lineup, like the Vérité, but they still create an absolutely stellar impression - a big, wide sea of sound that feels like it reaches far beyond your mind.

Stock Pads vs. Upgrade Pads

One of the interesting things you can do with the Aeolus, as with all ZMF headphones, is swap out the pads. And this is where our love train for these headphones gets delayed at the station. As much as we like the idea, swapping out the pads on the Aeolus was almost hysterically frustrating. Imagine a fitted bed sheet. Imagine that it’s just a little bit too small for the bed. Imagine yanking and tugging at it, trying to get it to fit. Now imagine that you’re using it to cover a pair of very expensive drivers, and you really don’t want to put your finger in the wrong place. That’s what it’s like trying to change pads on a pair of ZMF headphones. We have never wanted magnets more in our entire life.

We received our review model of the Aeolus with two sets: a pair of perforated suede pads, and a pair of leather numbers known as the Ori pads. There’s definitely some marginal difference when you swap out the pads – the suedes clamped down on the mids just a little, while accenting the highs, whereas the Ori pads presented what we felt was a more stock interpretation. Truthfully, unless you really get a kick out of fine tuning your sound, there’s no need to order extra pads. We know we’re in the minority here – there’s nothing more that the headphone community loves than digging into different pad types - but swapping them out was so annoying, and the result so marginal, that we can’t recommend it. Besides, the sound of the Aeolus is about as perfect as you can get; what more do you want?

Amp Pairing

Given that the Aeolus has an impedance of 300 ohms, you probably aren’t going to be driving these from your smartphone. They are good enough that you don’t really need a particular amp to make them sing, but it doesn’t hurt to have one. We tested the headphones with a variety of different amps, and definitely had our favorites. A good tube amp, like the Monoprice Monolith Liquid Platinum (full review here), really helped open up the low-end and give those gooey mids even more of a boost. We also had quite a lot of fun listening on a Burson Play (full review here), which gave the headphones some nice liveliness. The impression we got from the Aeolus was that it was remarkably forgiving - as long as you have a good-quality amp driving it, good things will happen.

Design

Looks and Build Quality

Predictably, the Aeolus look superb, and are built like a tank. The sapele wood was finished to an impeccable standard, with a delicious richness and warmth. We can confidently say that this extends to other models in the range, and other wood types as well. Not only have we handled just about every other model the company makes, thanks to our presence at various shows, but we also own a pair of Atticus, that one in burl wood. The quality control and craftsmanship on every pair is top notch.

We must admit that we aren’t huge fans of the grille design on the Aeolus. Compared to the extravagant curlicues of the Vérité and Auteur, it lacks a little something. However, we get the sense that this is very much a personal preference – you’d have to work very, very hard to call the Aeolus ugly. Simply because we feel it’s the least attractive out of the entire range doesn’t mean much here, because it’s like deciding who out of Idris Elba, Ryan Reynolds, and Robert Downey Jr. is the least beautiful. It’s a pointless exercise.

The hinges and headband are suitably robust, too. They are solid metal, with a headband finished in a very fetching lamb leather, embossed with the company logo on one side and a discreet ‘ae’ on the other. The height adjustment brackets look quite clunky, but move surprisingly smoothly. Overall, the impression is one of genuine care and attention to detail. One word of warning: for some reason, one of our cups became un-screwed from the height adjustment bracket, and it came loose just as we were putting the headphones on. The headband, which was under tension, fetched us a pretty painful whack on the side of the head. We’ve never heard of this happening with any of the other models, including the Atticus we own, which shares an identical hinge design. But you may want to check that your connection is secure before you put your pair on.

Connections

The cables connect to the headphones via a pair of smooth 4-pin sockets. We are often a little wary when we see pins that small – we’ve seen them get bent in the past – but we don’t feel like that would be an issue here. The pins feel suitably robust when we connect the cables, and there’s a handy slot so that you don’t get them the wrong way round. We’ll talk more about the cables in detail below.

Comfort & Fit

Whatever our misgivings about changing the ear pads, there’s no denying that they are stupendously comfortable. We quite happily wore these headphones for many hours, without any sign of discomfort. That was quite surprising to us, as we found the clamping pressure to be a little tighter than we would have liked - even when it wasn’t whacking us around the head. Still, it didn’t cause any problems in the long-term.

We directly tested these headphones against what we consider to be the most comfortable pair ever made, the light and airy Beyerdynamic Amiron Home (full review here). The Aeolus didn’t best the Beyers, but still held up remarkably well. The headphones are relatively light, at just under a pound, which is a few ounces less than the Atticus.

Accessories & Packaging

It’s not enough that ZMF make great headphones; they also make some of the best cables in the business. This isn’t hyperbole. We test dozens of headphones every year and are continually stunned at just how easily even high-end cables tangle. That’s not the case here. The cable that comes with the Aeolus feels brilliant, hardly ever gets tangled, and has none of the unpleasant tension and flex you find in lesser cables. Does it make a difference to the sound? Honestly, we don’t think so. We come down firmly on the side of the argument that cables don’t make a difference unless you’re running particularly sensitive equipment, like an ultra-high-end DAC. But they feel and look terrific, and are a joy to use. We had two cables to test: a standard 6.3mm connection, and a larger XLR.

The Aeolus also come with a carrying case: a big plastic number lined with foam. It doesn’t look particularly good – it has a rough and ready industrial aesthetic – but it’s ideal for travel, and will very happily protect your headphones. If you want, you can always buy a bespoke wooden box lined with velvet. Strangely, we haven’t seen this for sale on the ZMF website, but we imagine they’d be happy to make you one if you asked for it.

What We Like

• The ZMF Aeolus deliver superb sound, particularly in the midrange.
• The design, fit, and finish of the Aeolus is second to none.
• There’s a real sense that these headphones are meant to be treasured, even passed on – something you won’t get from other audio equipment.
   

What We Don’t

• Changing the pads on the Aeolus is a giant pain in the backside.
• The Aeolus are expensive, and may be out of reach for casual fans.
• Buying a pair of Aeolus typically involves a very long wait, as ZMF has a continuous backlog of orders.

Comparison Table

The Competition

Outside of the headphone-modding community, there are very few companies making handmade, bespoke headphones in the way that ZMF is. However, the high-end headphone landscape is particularly crowded at the moment, so there are plenty of models to compare the Aeolus to. Our first pick would be the Focal Clear. The French company makes some of the finest headphones on the planet, and the Clear do for metal what the Aeolus do for wood. The sound is light, crisp, and airy, with enough grunt behind it to bring the pain, should you require a little bit of bass. They are slightly more expensive than the $1,200 Aeolus, at $1,498, but they are definitely worth looking at.

If you can’t stretch to a pair of Aeolus, but you still want to experience great high-end audio, how about the Sennheiser HD650? You’ll pay under $500 for a pair, and even years after release, they remain a firm favorite among fans. The high-end isn’t quite as exquisite as that offered by the Aeolus, but it remains a benchmark, and the neutrality and balance that these headphones bring to the table is reason enough to check them out. You won’t get the same personalized experience – these are clearly a pair of mass-produced cans – but you will get excellent reliability and sound quality.

We want to compare the Aeolus to two other models in the ZMF line: the Atticus and the Auteur. The Atticus is very much our favorite headphone model from the company: a big, bassy, no-nonsense monster with a ton of energy inside it. Despite being a closed-back model, the soundstage is gloriously wide. It’s a little less expensive than the $1,200 Aeolus, and we do find that it’s a pair of headphones we keep coming back to – even while we had the Aeolus in our possession. If you want a classic, something that will never let you down, try the Atticus – or their sister model, the Eikon.

If you want something even more high-end, try the Auteur. Its pricey – upwards of $1,600 – and isn’t even the most expensive pair of headphones the company makes. Regardless, it sounds truly glorious. The emphasis is very much on the treble here, with excellent detail. We do think it sounds more closed-in than other models, and would consider it an acquired taste, but it’s worthwhile if you want something different from the Atticus or Aeolus.

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