ZMF Caldera - End Game Quality with a Price to Match

 4⭐️

 

+ Dynamic, fun tuning 

+ Top notch resolution and imaging

+ Natural timbre

+ Comfort

+ Impeccable build quality and materials

+ Includes a very sturdy case and impressive accessories

- Yoke rods are difficult to adjust

- Upper mids/lower treble energy a bit too much at times

- Light on the bass

- I don't prefer open back due to sound leakage and lack of isolation (subjective)

- Price

thaslaya's star rating system:

☆☆☆☆☆ - Fantastic!

☆☆☆☆ - Recommended

☆☆☆ - There are buyers but not for me

☆☆ - Can't see the appeal

☆ - Product is a failure

Disclaimer: 

This pair was provided for demo through a tour arranged by ZMF. They were returned after the review period. I receive no compensation, and all thoughts and opinions are my own.

I also feel the need to add another disclaimer here. I am a completely portable listener and have no desktop gear to speak of. That means I only had dongle DAC/amps to power these full-sized headphones. I know that may be sacrilegious to some audiophiles. If that's a dealbreaker, then feel free to read no further. But when the opportunity knocked, I had to answer, or I would have regretted it later. So, I jumped at the chance to join this ZMF tour and get my hands (and ears) on some TOTL headphones.

Gear used: 

● Samsung Galaxy s22 Ultra

● Samsung dongle

● Hiby FC4

● iFi GO bar Kensei

Source:

Listening was done through Amazon Music HD or Ultra HD.

Introduction:

ZMF Headphones is an audio company operating out of Berwyn, Illinois, right here in the United States. Zach Mehrbach is the founder, president, and designer, and his passion for headphones is on display with every set the company produces. Each headphone is handcrafted in the ZMF workshop and enjoyed worldwide thanks to their ever-growing list of international dealers. There are many models to choose from in both open and closed-back variations, and they also make desktop DACs and amplifiers as well. The Caldera is one of ZMF's newer products and features an 80mm planar driver with CAMS patent pending technology. Let's break them down and see what this TOTL model can do.

Build, fit, ergonomics:

ZMF offers many customizable options when ordering from their site, from the type of wood used for the cups to the pads and cables. This particular Caldera model is the limited-edition RedHeart wood variant with a ruby magnesium chassis, gunmetal grille and yoke rods, a ruby bull bolster band (BBB) strap, and a leather headband assembly. These come shipped in an incredibly sturdy carrying case. It provides a ton of protection and can even be locked for added security. The headphones are built from some of the finest and most beautiful materials. The build quality is absolutely superb! The headband has a thin layer of padding wrapped in very supple and soft leather. The BBB strap is made of a thicker, sturdier leather, but it's still soft to the touch. The RedHeart cups are eye-catching and just oh so pretty. The stylized metal grill adds a great aesthetic. The yoke rods feel very strong, although they are a bit stiff and hard to adjust. I fear that scratches can build up over time, but that can only be determined after long-term usage. The Calderas have a decent weight but also don't feel too heavy or fatiguing during long sessions. The headband does a great job of distributing the weight evenly without any hot spots. The clamping force is just about perfect for me, not excessively tight to cause undue pressure or too loose to prevent a proper seal. There are two different pairs of pads included, perforated lambskin leather and perforated suede. Both are super soft and comfortable, but they also have unique sound qualities, which I'll touch on later. Pad rolling is a pretty straightforward process, but it does take a bit of patience and finesse to get them on just right. The insides of the cups have plenty of room; even my large ears don't touch the drivers. The stock cables that were included in the kit are a bit thick and unwieldy. They are sturdy and well-built, but I strongly prefer braided cables that are more pliable and less stiff. ZMF offers alternative cable options, some of which may be more suited to my preferences, but they were not included with this particular review unit.

Sound impressions:

During the tour period, I had both the Caldera and Atrium Closed, so I will draw comparisons between the two throughout the review.

I would categorize the Caldera’s tuning as neutral to neutral-bright. The bass and lower mids are fairly even, but the upper mids and treble are slightly boosted. This results in a bit more energy and sizzle than I prefer. I also wouldn’t call it the a “fun” or dynamic tuning, but it is mostly balanced and a great option for extracting every bit of detail and resolution. The general consensus regarding ZMF's house sound is that it is natural, organic, and analog. While the Caldera mostly adheres to this approach, it exhibits a greater level of detail and resolution and can sometimes sound more analytical than musical. The soundstage is absolutely amazing and expansive. While I typically gravitate towards closed-back headphones for their isolation, the exceptional soundstage makes it a worthwhile trade-off. The openness of the cups does help, but it is still beyond that of any other open-back headphone I've heard before. The imaging is another strong suit of the Caldera, and it's the best I've ever heard—by a large margin. Each note and sound can be heard with pinpoint accuracy. Detail retrieval is also very strong, and subtleties can be clearly heard throughout the music. Yet, at the same time, they keep from sounding too overly clinical or cold. The timbre is very natural and organic with vocals and instruments alike. In fact, the combination of detailed retrieval and natural timbre results in the absolute best vocal presentation I've heard to date. I discovered subtleties within the music and vocals that I hadn't been able to pick up on before. I was constantly clamoring for just one more song, so I could hear my favorite tracks in a new light. The note weight does leave a bit to be desired. It is not thin per se, but I would have liked it to be a little thicker. The tour kit did not include ZMF's mantle mesh tuning kit, which can be used to make slight adjustments to the frequency response. However, it can be purchased separately if further customization is desired.

Here, I'll add some brief observations on the differences between the leather and suede pads. The lambskin leather does add a slight increase to the bass, but it also seems to emphasize the upper mids that were already a bit too harsh for me, so I opted for the suede. When using the suede, I found the bass to be slightly leaner, but that was a worthy sacrifice to tame the highs a bit. I usually prefer a bass response that is north of neutral, and although the quality is great, I would definitely welcome more quantity. I couldn't detect any noticeable differences in soundstage, comfort, or seal, so my primary reason for using the suede is to reduce the energy in the upper frequencies.

●Lows - The Caldera has decent bass for an open-back headphone, but as an almost exclusive iem user, I find most open-back sets to be severely lacking in bass. The Caldera actually has more bass than other headphones I've heard, but in general, I would still prefer much more quantity. They are more sub-bass focused than mid-bass, and the bass can rumble deep and low when called for, but I feel that the sub-bass extension rolls off a bit early. I also find it lacks a bit of warmth and "fun" that more mid-bass would bring, although to its credit, there is no bleed into the midrange, and it is well separated. The Caldera utilizes planar drivers, which ensure the bass is fast and tactile with a quick attack and decay. These characteristics lend themselves beautifully to rock and other genres where separation and detail help the bass from sounding congested or busy. However, the attack could use more impact, and I typically prefer a slightly slower decay for a longer-lasting presence and reverberation. Overall, it's hard to find too much fault with the bass on display here. The Caldera's low end really is of fantastic quality, but in my opinion, it would benefit greatly from more quantity, which would elevate it to the next tier.

●Mids - Let's get this out of the way right off the bat. The midrange of the Caldera is the most natural-sounding I've ever heard. Every instrument has incredibly realistic timbre, and vocals are organic, effortless, and intoxicating. Everything sounds remarkably lifelike, creating the illusion of actually being present in the studio or recording booth with the artists. This one frequency range almost makes up for the issues I have with the others...almost. Though experiencing the Caldera's mids has helped me realize that I don't necessarily prefer them to be as natural as possible. I have a penchant for a warmer, more forward midrange with an intimate presentation, but it's really hard to find fault with anything on display here. Despite how good the mids are, they aren't quite perfect. My only gripes are that male vocalists are slightly recessed compared to their female counterparts and the upper mids have a bit too much energy on some tracks. Despite any very minor criticisms, the midrange is truly exceptional and the most notable aspect of the Caldera's tuning.

●Highs - Here comes trouble treble. Yes, it's superbly open and airy with a fabulous soundstage and enough sparkle to make a Twilight vampire blush. Unfortunately, it just has a bit too much sizzle for me and can sound thin and harsh on some tracks. Cymbals, snares, hi-hats, and claps all sound accurate and true without any real sibilance, but the overall treble energy becomes fatiguing at high volumes over short periods. Now, I don't have much experience with full-sized planar headphones, but most planar iems I've heard can have a thin, harsh treble. Maybe the planar drivers utilized in the Caldera are to blame for how the treble hits my ears. Now, it's far from a dealbreaker, and I've definitely heard much worse tonality, but I do wish the highs were toned down just a bit. I believe those who appreciate top-end air, extension, and clarity with a hint of spice and sizzle will certainly find much to love here.

In conclusion:

There's a reason the ZMF Caldera is considered by many to be an endgame headphone. It is a masterclass in technicalities, comfort, and build quality. From the materials used to the accessories, the care and craftsmanship that goes into every pair is obvious. The tuning does not fall squarely within my personal target, but I can still attest to the quality of the sound and timbre. If I had the money, I would absolutely have a pair in my collection, if only for the imaging and soundstage. Watching movies is an epic experience with the Caldera. It's the closest I've come, with portable gear, to replicating that theater sound. As I stated earlier, I had both the Caldera and the Atrium Closed during the same tour period. I was fortunate to be able to do some A/B comparisons between the two, and they are both incredible in their own ways. But if push came to shove and I had to choose between the Caldera or the Atrium Closed, I would take the latter. They are a slight step down in soundstage, naturalness, and overall technicalities, but they satisfy my tuning and isolation needs better. A have to give huge kudos to ZMF for the quality of their products. I have experienced nothing that comes close to these and probably won't until another ZMF headphone can surpass them.