ZMF Caldera Closed Review

@zach915m You might have to tell me. I'm not sure which pads are which

 

One pad should be leather and suede hybrid, another one full protein and then the other all lambskin. Is that the case?

They also should have been in labeled pad bags. Happy to send more bags out to help if needed as well.

 

I think so. Only one bag though. The ones in the bag seem like protein and the bag is marked protein.

The pair on the headphones are the thicker so I assume those are the leather hybrid and the thinner ones are the lambskin.

 

I had these just before @roshambo123 and I just left on the pads that were already on, and didn't see any extra bags.

First off, I would really like to thank SBAF and @zach915m for the chance to hear a $3500 headphone for an extended period of time, at home in my own setup. It’s legitimately amazing to have that opportunity, and likely something I would not have done on my own - I heard the CC at Canjam SoCal and loved it there, but I seriously doubted it would be usable in my own tubey setup at home and wouldn’t throw $3k+ around for the sake of trying.

Second, I feel pretty lame posting my impressions coming on the heels of @theveterans exceptionally thoughtful and detailed notes and comparisons. Personally, I struggle to put what I hear into writing, so my impressions tend to be much more qualitative and I get that some people may not find that quite helpful. I’m relatively new to the hobby and still working to be more detailed and quantitative in my notes.

At first, I was right about the synergy with my all-tube setup. All below notes were using the Abbas U1 tube dac, and all amps were tubed. I tried it on the Glenn OTL (a muffled, blobby mess that felt overly dampened, like thick smoke between me and the music… sometimes details would peek through the smoke beautifully but overall it just didn’t work. On the Cayin HA-300b it was good, but nothing special, no unique synergy to my ears. I made a note to return to the Cayin, but got waylaid by the Stratus.

I first tried it on the Stratus v3 using a 2k balanced cable and while it was the best amp so far, it still left me wanting more. Towards the end of my too-limited time with them, I swapped the cable for the unbalanced 6.3mm stock cable, now via the Low Z output on the Stratus, and the synergy really kicked in. I was and still am surprised by how big a difference there was between the balanced connection and the unbalanced low-z output. Once I had that connection locked in, it was hard for me to stop listening.

In the earlier combinations, the CC felt limited to me. First, the overall positives regardless of amp - for a closed back, it had a very spacious feeling. It never felt closed-in like other closed backs, but the stage was more flat and vertical and while I was amazed by the ability to simulate a wide stage within the cups, when I would switch over the Atrium Opens, the difference was clear (not really a knock on the closed back CC, but it was interesting to me how it could seem so wide open while listening to it, but when I moved to a true open back, the simulation fell apart). CC feels like it is blowing things out to create the impression of a vast stage, when in reality it’s not that vast. But by creating that impression, things feel more spread out and less intimate. In my notes, I wrote that it reminded me of the Auteur OG but splayed out in a way that loses the immediate intimacy The CC had a wide, flat wall of sound - not as high or as deep as the AO.

I am not really a fan of planars in general. I get the metallic tinge, lack of decay and thin edges of notes. It’s not a judgment, it’s just that I prefer dynamics (and electrostats, for that matter) so I guess the biggest compliment that I can give the CC is that it very much does not sound like a planar to me. I’ve heard the Susvara in show conditions and just didn’t find them enjoyable, for me. The CC had a very natural tone, lots of microdynamics but fell behind the AO in terms stage and macrodynamics, for me.

So back to the magic combo of the CC and low-Z SE input on the Stratus, all my comments below reflect that, and comparisons to the AO were on the balanced jack. The AO was more open and expansive, more macrodynamics, and a heavier emphasis on upper bass vs sub-bass. AO had more treble energy, which was strange to me as I am particularly treble sensitive and love the AO because it’s so measured in the treble. The CC (on this setup) was richer and darker, with less treble. Really was a unique combination to me, that I haven’t been able to capture before. I found myself getting totally lost in songs I’ve heard hundreds of times before.

The CC felt darker, more sub-bass and it was just a little bloomy, but in a very pleasant, enveloping way. It felt more congested to me, that wall or blanket of sound, but the plankton was exceptional so I’d still get this wonderful level of detail even within the darker enveloping sound. Not a high stage, but a wide one. With certain songs, I’d get this heavy, holographic reverberation experience within the cups (particularly evident on Weeping Song by Nell Smith & The Flaming Lips). I chase holography and this combo was probably the best I’d ever heard on my setup. Male vocals (Neil Young, Tom Waits, Leonard Cohen) shone through the darkness.

One of my favorite tests of any gear is Mercy, Mercy, Mercy by Cannonball Adderley. The degree to which I can hear into the crowd conversation, the hoots and hollers, the spacing, tells me a lot about a headphone. The CC’s stage shape portrayed that club-like setting perfectly - one of my favorite songs, replicated better than I’ve ever heard on any other headphone. The openness of the Atrium doesn’t stage this setting as accurately as the CCs do. I feel like I can hear the cigarette smoke in the room and the coughs in the corner. The bass felt more real, like the reverberations I’d get in a low-ceilinged club. The CC felt like a VR simulation of that night in that place. Or so I imagine, to be clear. That bass heft was also evident in the Hey, That’s No Way to Say Goodbye. Clean phat bass.

I loved the experience of listening to these, and I genuinely miss them. I’m not sure how likely I am to ever own a pair, but the experience of listening to them has stuck with me a lot in the 5 days since I heard them, and I hope that I can have a pair some day. I keep emphasizing that my experience is fairly unique to me (a planar on a double dose of tubes) but the CC were rich and thick, but allowed exceptional levels of detail to shine through. A heft to the notes that sometimes got bloomy but enjoyably so. I started out liking these for the detail they offered, then disliking them on most of my gear to finally loving the living hell out of them on the 'right' setup which just emphasized how big a role synergy plays at this level.

 

USB > DANTE > AES > Yggrasil A1/GS > Pietus Maximus > Caldera Closed (XLR)
USB > DANTE > AES > Yggrasil A1/GS > Piety > Caldera Closed (1/4")

This review was based on the loaner. Thank you @zach915m

TL;DR, Caldera closed has the traditional ZMF house sound with low fatigue, superb bass that reaches low but doesn't overwhelm, and excellent cohesion that is held together by the plastic-free timbre that doesn't sound like a traditional planar. It ranks with Susvara and LCD-4.

Enough has been said already so I'll just give my notes.

- very low fatigue
- dark tilt, warm
- work great for rock. Electric guitars are smooth as glass
- work great for techno. Bass = party mode /enable
- Genremaster, sounds pretty solid on everything I tried.
- character is laidback at first even felt somewhat slow motion
- cohesion is great, bass needs seal. wearing glasses causes bass to disappear
- stage is quite wide for closed backs
- timbre is really good for planar, no plastic/artificiality
- Forgot for a moment they were planar
- engagement factor makes you want to keep them on
- comfort is just at the limit of what I can handle in terms of weight
- Very easy listen on MJ3
- Piety works nicely and adds some extra zest over MJ3, which has better bass extension and quality
- Pietus also works, prefer Piety>Pietus here tho for moar lively. MJ3 is my top choice though
- dimensionality isn't holographic, but for closed backs it's great
- HD6XX is more lively in mids to me than Caldera Closed
- outrageous amount of detail on MJ3 I haven't heard in middle and low frequencies
- at the same time they aren't dry while having so much detail. It's a bit magical
- I do not want to send these loaners on. At all lol.

 

Thanks for the opportunity to try these lovely headphones.

Did all my listening with the Hybrid pads on. Found the all leather ones to veil the sound too much compared to the hybrid pads.

The Caldera is a warm-neutral headphone that seems to play well with every type of music I threw at it. It doesn't really sound like a planar headphone also not exactly like a dynamic headphone. It kinda floats in a space between the two. Not as natural as a dynamic but not as aggressive and forward as a planar. The comfort is top-notch and I could wear them all day with no fatigue. The system Zack installed to help with the top end sibilant works wonderfully. Though I felt on some songs it cut a little too much off. The bass is fantastic and the most planar like sounding the headphones become. The headphones are kind of a jack of all trades. Completely unoffensive wonderfully detailed and precise in instrument placement in its above average sound stage.

I can't say I was ever truly wowed when listening to them but I was never disappointed to put them back on. They take quite a bit of power to run properly but they worked well on my Master-9, Mainline, and TorBalanced. I enjoyed the CC most on the tube amps I have. It really helped open up the sound stage and lift a little bit of the veil I was still hearing with the hybrid pads on the CC.

I was also able to power them properly on my ifi Gryphon xDSD. I don't know that I would personally use them as portable headphone just due to the price but some might want to. So I figured I would test it. They weren't quite as reveling on the portable but still quite enjoyable. The over all sound was darker but that could just be how the Gryphon sounds. Haven't had a chance to really test that out yet.

If you are looking for a top of the line closed back headphone that will work with all music, doesn't offend in any way, and has fantastic comfort I would stop your search here. Also, If you are looking at figuring out what to change in your system the CC would work wonderfully in that situation. They are very reveling and true to there tuning.

Would I buy a pair?
Honestly? No. They are wonder and balanced but they are too "safe" sounding for what I'm looking for in headphones. Which I completely understand is something very desirable for some in the high end headphone world. I started there in my high end journey but ended up liking the headphones that have a little wonky-ness in there sound. Personally I would buy the Bokeh over these. Which is probably nuts to some but preferences can be weird.

P.S. The CC sound terrible on the Crack and the Crackatwoa. Which I expected since those amps are meant to be used with 200ohm and higher headphones.

 

Loaner impressions

Big thanks to Zach for the loaner and to the gear masters for organizing it.

Gear used: Soekris 2541, Studio B, Mjolnir 3.
Headphone for comparison: ZMF Atrium

Atrium fed from my Studio B. Caldera Closed mostly from the Mjolnir 3.

I was pretty excited going into this loaner. After the Caldera Open loaner, I was pretty hyped to hear what the closed back could do, especially considering I am in the market for a new closed back headphone.

Not Sound Stuff:

Comfort and build quality is the typical ZMF we all know. Comfort is good, if a little on the heavier side, but evenly spread out. The small changes that have been made to the suspension strap and headband over the years has culminated in a very comfortable headphone, despite the extra weight it has over the mostly plastic competition. Build quality and looks are unmatched in the industry.

Sound Stuff:

Maybe I went in with too high of expectations, but while I did enjoy the Caldera Closed, it is lower down in the ZMF hierarchy for me. While that might sound bad, I don’t think Zach has ever made a headphone I disliked. I’d 100% buy a CC over 98% of the other planar headphones on the market.

I feel I must also stress that I typically do NOT care for planar headphones. I have tried dozens over the years, from budget to kilobuck and in all that time I enjoyed exactly 3 of them. The ZMF Blackwood and Ori from Zach’s t50rp modding days, and the Caldera Open. Note that all three are ZMFs.

Atrium comparison:

The CC excelled in complex passages, though the Atrium wasn’t far behind. I felt that the CC was a little stuffy in back to back comparison, having a negative impact on staging. A little unfair considering the Atrium is an open headphone, but it was there nonetheless. I’d say the CC openness, staging, etc was decent for a closed back. Small nuances in the music, dynamic swings, etc, were all more prominent on the Atrium. This is something I think dynamic headphones do very well, and I put a very high priority on it (probably why I don’t get along with most planars). Notes lingered a little longer on the Atrium, whether this is due to wood reverb or something else, I’m not sure. This could even be a negative for some, but for me, I love it. It’s a quality the Atrium shares with the OG Auteur, which is one of my favorite headphones.

For pads, I preferred the stiffer/thicker non-hybrid pads. I think they were the lambskin (felt a lot like my own ZMF lambskin pads). The flatter protein pads were a bit too muffled for my taste. The hybrid was decent, but I preferred the bass with the lambskin, not as soft hitting, better defined.

If I were in the market for another open headphone, I’d have already happily bought a Caldera Open. The closed version just didn’t mesh with my preferences as much as I had hoped. If you’re a big fan of planars though, definitely give this one a listen as it is still one of the best.

 

I had a great week with the Caldera Closed loaner. I’m incredibly appreciative to have gotten the chance to try these out at home. Thanks @zach915m @ChaChaRealSmooth and SBAF for the privilege!

I’m pretty spoiled when it comes to headphones these days, so it was going to take a lot to convince me a $3500 closed-back was worth considering. My three headphones in rotation are a Meze Elite, Atrium Closed and OG Auteur.

My chain is iFi Zen Stream (USB out)>Yggdrasil A2 (SE out)>ZMF Aegis. I’ve got some nice tubes rolled in the Aegis at present and didn’t change anything while the CC was here. For those that care, I used my ZMF 2K Copper cable the whole time.

I spent the first couple days only listening to the CC without doing any A/B comparisons with my other headphones. I just wanted to get a feel for the CC in isolation. They had the Caldera Thick Lambskin (Top Perforation) pads installed when I got them. I used those for a few hours, but decided it made more sense to switch to the stock Caldera Hybrid (Top Perforation) pads to get a baseline assessment of the sound.

First and foremost, they sound like a ZMF. In my book, that’s a good thing. I’ve owned close to 10 different ZMF’s over the years, and I tend to get along with the tunings of Zach’s creations. The CC was no different.

To me, these have a warm and mellow vibe. They are highly-resolving at the same time, which is an impressive feat. The thick lambskin pads were warmer than the stock hybrids, and for me were a bit too warm. I ended up preferring the hybrids overall and kept them on for most of my time with the headphones. I briefly tried the thinner Bokeh Protein pads, but didn’t really like those at all.

The CC seemed to be a great match with my DAC/amp. To be fair though, I haven’t found any headphones that don’t sound at least very good with the Yggdrasil/Aegis combo when you factor in the extensive tube-rolling possibilities of the amp. I used the SE-out of the Aegis using the lowest output impedance setting, which I believe is 5 ohms. These required a bit more power than my other headphones to get to the same volume, but in general I don’t think they’re particularly hard to drive.

After getting a feel for the CC, I tried to do some comparisons with my Elite and Atrium Closed. I didn’t go about this scientificly or anything, but I tried to adjust to a similar volume-level and used the same handful of tracks while going back and forth.

I expected the CC to have more bass-quantity than the Elite, but if they did, it was only by a small amount. Both headphones have great, articulate bass that extends all the way down. My Atrium Closed has more bass overall than either, even with the Caldera Suede (Top Perforated) pads I use most of the time, which tame the bass the most of all the recommended pads. All three headphones get top marks in the bass department.

Mids and vocals was a tough comparison. I prefer vocals on my ZMF dynamics with bio-cellulose drivers. The OG Auteur has my favorite midrange. The CC was excellent here, but didn’t stand out amongst my 3 headphones. I found human voices a little more natural on the Elite, which was the only other planar I had on hand. The CC came across a hair drier in the mids, but only in this A/B comparison. When I listened to the CC by itself for an hour or so, I never detected anything negative. All 4 of these headphones are great in the mids.

As far as treble is concerned, my Elite won out. It is very open and airy and has a little more detail up top. Of course, the CC is a closed-back, so it’s not really a fair comparison. Against my Atrium Closed, I found it to be a toss up. I could listen to either without any fatigue setting in. The CC acquitted itself nicely in the highs.

The soundstage of the CC was superb for a closed-back. The Elite is noticeably more spacious-sounding. The CC definitely one-upped the OG Auteur in this department, so that’s saying something. I thought the imaging was precise, and it just sounded natural no matter what kind of music I was listening to.

After reading so much about the CC, and the Caldera Open before them (which I also got to demo), I thought one of these might temp me away from my current trio of headphones. Turns out I remain content with what I’ve got. That’s a huge sigh of relief. I don’t like thinking about what I’d have to sell to come up with the cash for a Caldera!

To sum things up, the CC is another excellent pair of headphones from ZMF. Zach and his team have created another winner that is certainly worth considering if you’re in the market for a TOTL closed-back. Thanks again for the opportunity to try these out!