This review is a special one for me. Not only is it my first review ever, but I get to review a pair of headphones from my favorite company. I’ve been a fan of Zach’s headphones since the first time I saw them a few years ago – leather, wood, metal, and sonic bliss all in one package? I knew I needed a pair. It was a little over a year ago that I was fortunate enough to get my hands on my first ZMF, a Verite Open Purple Heart. Since then…well just check my Head-Fi signature and you can see what happened! I really went down the rabbit hole.

After experiencing the Caldera Closed at CanJam NY, I reached out to Zach, and he was generous enough to loan a unit for me to try my hand at reviewing.

Being my first review, this was a very fun challenge! I hope you all enjoy reading my thoughts.

Tech Specs:
Wood: Shou-sugi ban Ash
Chassis Material: Aluminum
Weight: 541 grams
Pads used: Caldera Thick

Audio chain for this review:
My desktop setup is Spotify > USB > Schiit Gungnir Multibit A2 Unison > Schiit Mjolnir 3. I did all my testing on the Mjolnir 3.

Tracks used:

• Homemade Dynamite – Lorde
• Tennis Court - Lorde
• Black Mambo – Glass Animals
• Gooey – Glass Animals
• Heat Waves – Glass Animals
• Billie Jean – Michael Jackson
• Reckoner – Radiohead
• Interstellar Medley – Hans Zimmer Live in Prague 2017
• Inception Medley – Hans Zimmer Live in Prague 2017
• Pachelbel: Canon and Gigue for Three Violins and Continuo in D Major: Canon (Jean—Francois Paillard)
• Riders on The Storm – The Doors
• Remembrance – Balmorhea
• Mine – Bazzi
• LEMON – N.E.R.D – bass
• Radio – Lana Del Rey
• Everywhere – Fleetwood Mac
• Hotel California Live MTV 1994
• Crystalize – Lindsey Stirling
• 24K Magic – Bruno Mars
• Disasterpiece – Slipknot
• Unsainted – Slipknot
• Nero Forte – Slipknot
• With You – Linkin Park
• Formula – Labrinth
• Let Her Go – Passenger
• Round Here – Counting Crows
• Beat Bizarre – Save the Cheerleader, Save The World
• Give Life Back to Music – Daft Punk
• Pink Floyd - Dark Side Of The Moon (full album)
• Nothing In My Way - Keane
• Riders On The Storm - The Doors
• Spanish Sahara - Foals
• Bubbles – Yosi Horikawa

Dynamics
In Riders On the Storm you can easily appreciate the rain sounds as a backdrop in the music, even while the drummer hammers away on the ride cymbal. The details are not lost or washed out by any individual instrument, whether it’s the piano, guitar, or drums. Reckoner is also a great example, with the drummer in your right ear, guitarist in your left, and a subtle tambourine slap and piano supporting in the background. It is stellar how well the details are preserved, despite the rapidly rising and falling instrumental sounds overlaid on subtle noises. Dynamics also are wonderful in orchestral music, such as the Hans Zimmer Live in Prague - Interstellar Medley. The track’s subtle background of violins, drums, horns, and piano are still crystal clear despite the prominent electric cello and horns. The listening experience is intense. While listening to some headphones can be like watching an LCD screen TV, the Caldera Closed is like watching an OLED TV- the intensity is simply greater, there is more depth and information for your ears to extract.

Instrument Separation, Resolution, Detail retrieval, and layering
The instrument separation and layering on the Caldera Closed are impressive, rivaling the Caldera Open in my testing. For example, in Spanish Sahara - Foals, there is a buildup throughout the song, where it begins with drums, adds guitar, and keyboard, and all the components come to a head in an epic medley (around 4:15). Despite the depth and layers, you can still pick out each instrument, each level of detail, even as the music intensifies. Another great example is in Hotel California, Live On MTV, 1994, where each instrument adds to the medley, but can easily be followed throughout the track. In terms of vocals, in Round Here - Counting Crows, you can practically imagine the room that Adam Duritz is singing in - the size and mild echo - and can hear his breaths while he sings! In the Hans Zimmer Interstellar Medley, you can hear the instant the drummer’s sticks make contact with the cymbals. The Caldera Closed does a wonderful job of bringing out these small details in songs.

The resolution and detail retrieval on the Caldera Closed is similar, but slightly worse than the Caldera Open. I believe this is simply due to the closed back cups muddying some of the sound. One caveat - in a room with any significant noise, I noticed better detail retrieval than the Caldera Open, since any ambient noise was interfering with my listening. In a dead silent room, Caldera Open would win in terms of resolution.

Soundstage
This is one of the most impressive features of the Caldera Closed. To put a number to it, to my ears the soundstage is perhaps ~80-90% that of the Caldera Open. Normally a closed-back headphone makes me feel somewhat claustrophobic (which is why I shy away from them), but the experience on the CC was delightful. Occasionally, I would forget that I was using a closed back! In terms of soundstage, it is easily the most impressive closed back I have ever tried. One thing I did notice, perhaps thanks to the closed cups, is the music felt more intimate and engaging than the Caldera Open. Thus, although there is some loss of soundstage versus an open back, I think it is marginal, and absolutely worth the sacrifice for sound isolation.

Imaging
I love using Bubbles – Yosi Horikawa to test imaging. It’s a binaural recording which really tests a headphone’s imaging capabilities. With the Caldera Closed, you can pinpoint exactly where sounds are coming from and follow them as they move in space, much like the Caldera Open. In this recording for example, there is a bouncing ping-pong ball moving from in front to behind your ears, and it is so realistic that when I closed my eyes it was easy to imagine the ball bouncing along its trajectory! With regular tracks, the imaging is also stellar. In most music I found that I could pinpoint sound sources within a 5-10 degree angle. Interestingly, it was also easy to imagine in my mind the “size” of that point of sound in space, creating a 3D mental map where each sound was emitting from within the cup. In comparison to the Caldera open, I could not really appreciate a difference in the imaging capabilities; they are very similar to my ears.

Bass
I found the bass on the CC to be punchy and visceral yet refined. For example, the bass in Hotel California – Live on MTV, 1994, the kick-drum feels like a punch to the ears (in a good way!); you experience the heft of the sound. The CC bass frequency response is very slightly elevated versus Caldera Open, and not bass light or rolled off in the low end. Compared to the Caldera Open and Susvara, the Caldera Closed bass is more pronounced and stronger, especially against the Suvara whose bass is lighter and airier to my ears. The speed of the bass is also very good, indistinguishable from the Caldera Open to my ears. In heavy metal with rapid double-bass pedal work, you can clearly hear every single kick drum beat without any bleeding into the next (for example in Slipknot’s Disasterpiece). I would rank the Caldera Closed bass performance as better than the other headphones I compared it against (CO, VC, VO, AO, Susvara).

Sub-bass
The sub-bass of the Caldera closed is excellent. I found in tracks like LEMON – N.E.R.D, and in the Hans Zimmer Live in Prague Dark Knight Trilogy Medley the sub-bass really stood out. The texture is also excellent and superbly smooth. The sub-bass is not laid-back. It is quite in-your-face, but it is not overwhelming, and I love how it brings out subtle low-end details. It truly is impressive, to the point where it almost feels like I’m listening to my speaker system with a dedicated subwoofer with how far into the low-end it can reach. I had absolutely no need to apply EQ to sub-bass frequencies on the Caldera Closed. I find that the CC sub-bass outperformed that of all other headphones I compared against (CO, VC, VO, AO, Susvara).

Overall tuning
This is where Zach knocked it out of the park. The tuning of the Caldera Closed is spot-on. The overall tuning is well balanced, without any component of the frequency spectrum being overwhelming or too weak. Bass is beefy and strong, without muddying the overall sound profile. The treble peaks are not overwhelming, but do a great job of bringing clarity to the music. I would not change a thing with Caldera Closed’s tuning, and I didn’t feel the need to apply EQ at all. The stock tuning of the headphone is dang perfect in my opinion and addresses two shortcomings of the CO for me – the sharp treble peak/mild sibilance and need for a bass boost. With my Caldera Open, I find that in certain songs (ex. Disasterpiece, Nothing In My Way, Reckoner) , hi-hats and cymbals can be a bit sibilant. However, when testing those songs on the Caldera Closed the sibilance was absolutely tamed.

We discussed the pros, now for the cons…
No headphone is perfect for every listener, Caldera Closed included. To me, there are very few things wrong with it, and I really had to think and listen hard to find shortcomings. There are a couple I want to mention. 1) the resolution and clarity is slightly diminished compared to the Caldera Open, and 2) in certain songs, there is a bit of muddying of the sound. I think both are just due to the closed cups. Neither is a deal-breaker, and really only noticeable with direct comparison to the Caldera open.

Pad and mesh rolling the CC:
This review was performed with the Caldera Thick pads, and stock (red) mesh.
Due to work I did not have time to roll pads, but I will update this review with my impressions.



The most important thing I look for in headphones is immersion. I want a pair of headphones that does not just present music to me, but makes me experience and feel a song, no matter how many times I’ve heard it before. Did the Caldera Closed achieve this?

Before I answer that question, I want to say – from the get-go I could tell the Caldera Closed would be a good headphone. I loved listening to it over the past few weeks while writing my review. It is a great all-rounder. Classical music? Oh yes. Rock and metal? This is it, chief. EDM, pop, or rap? Pick up the dang Caldera Closed! Anything I threw at it just sounded good. It was clearly very capable, and it became my go-to headphone during the past few weeks, so much so that even my beloved Susvara has not been on my head in weeks. My appreciation for the Caldera Closed, and what a good closed-back headphone sounds like, has grown since Zach sent me the headphone.

But, back to the question above. Did it meet my ultimate test? I found out the answer just a few days ago. And the answer is a resounding yes.

A few nights before publishing this review, I had a truly magical experience listening to The Dark Side of the Moon on the Caldera Closed. I had a tremendous appreciation for the headphone before that, but that album just completely enthralled me on the CC. I don’t think I have ever heard this album sound so good! Maybe the mood was just right, or maybe my audio chain just struck a magical synergy that night; but most likely, it was just the Caldera Closed doing its magic. When Brain Damage and Eclipse came on, I was teleported back to 2017 when I went to see Roger Waters in concert with my father. I could imagine the concert so clearly – the prism of light, and the color spectrum being shined across the audience in a wave, the spotlights shining on the band as they played that epic song. That concert was incredible, and Caldera Closed brought that wonderful memory back to me in such vivid detail, it nearly brought a tear to my eye.

Is it the most “natural” or realistic presentation of music? No. Caldera Closed is a distinctly ZMF product – it focuses on musicality, rather than an ultra-realistic performance, and that classic ZMF house-sound has not been lost in this headphone. Like using the proper tool for the job, if you want to have a deep musical experience, the Caldera Closed provides that.

So, would I buy Caldera Closed for myself? Yes. Writing this review has changed my perspective on closed-back headphones, which I usually completely avoid in favor of open-backs. These headphones really do it all – the great detail retrieval and excellent imaging, dynamics, bass and sub-bass, all similar to the Caldera Open, but with sound isolation to boot. But, keep in mind, we cannot simply simply call this headphone a “closed-back” version of Caldera Open. It has a sound signature, tuning, and musical presentation unique and distinct enough from the Caldera Open, that it would beautifully complement, rather than outright replace, a Caldera Open in your collection.

For those of you who are looking for a closed-back planar, I highly recommend the Caldera Closed. Zach has produced another masterpiece, taking the best properties of the Caldera Open and putting them into a closed-back package, creating yet another unique headphone in the ZMF lineup.
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Thanks to Zach for giving me this opportunity, I had a ton of fun testing out the CC and writing this review. To all the readers, I hope this review was entertaining and enlightening. Happy listening everyone!

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