Introduction

ZMF stands for "Zach Mehrbach Films," so you might be wondering what that has to do with headphones. The ZM behind ZMF perhaps originally saw an opportunity in film-making and Hollywood, but selfishly I am glad that life had another plan for Zach. He started, as many others in this industry such as Dan Clark Audio and Mod House Audio, by modifying the Fostex T50 planar magnetic headphones ~12 years ago. That soon led to the first of many ZMF-branded headphones, which all happened to be dynamic driver headphones, including the development of in-house drivers and a boutique service manufacturing them on a per-order basis. This allowed ZMF to also delve deeper into custom designs using wooden earcups and the brand has since grown to include other people and a batch manufacturing ethos which still retains the design philosophy of headphones that many would consider works of art as much as they are tools for listening to music. I'd go as far as to say this is the one remaining brand I was eagerly wanting to cover and I was delighted to finally meet Zach and the rest of the ZMF team earlier this year. I did not leave alone either with ZMF being kind enough to provide a review unit of the Caldera to TechPowerUp!


The Caldera is ZMF going full-circle from its roots of modding an existing open-back planar magnetic set to making its own planar magnetic headphones. I understand this is a project that was 6+ years in the making with lots of failures as well as lessons from other ZMF products learned along the way. The name itself hints towards a cool implementation of the magnets used in the driver, which we will talk more about over the course of this review. As with pretty much everything ZMF, the Caldera also comes in a variety of options and finishes depending on your patience. At any given time you can choose two different wood cups and grill/yoke rods combinations with the more expensive option used for the thumbnail of this review. But ZMF also puts out special releases every few months using different base wood and finishes, including with stabilized resin, to have one-of-a-kind Caldera headphones that many eagerly wait for and purchase instantly on release. One such example is seen in the cover photo here, and you can take a look at this video for past examples. In addition to simply looking unique, the different wood densities can also affect sound decay and speed slightly, in addition to the overall weight of the headphones, to where you should keep in mind that there may well be slight differences from unit to unit. But the general sound signature and user experience will similar enough to where this review of the base Caldera version should still be highly relevant to anyone who's already become interested in the ZMF craftwork and aesthetics, so let's begin with a look at the product specifications in the table below.

Specifications

Packaging and Accessories

The ZMF Caldera I have here is a demo unit that was in use at CanJam London which, along with many, many other headphones, made the cross-ocean journey not in retail packaging. As such, I was thankful that ZMF was able to share a photo of the case the Caldera and other recently purchased ZMF headphones normally ship in, unless you pony up the extra for the fancy wood display case. This is a hard case made by Seahorse—the SE 430—and has the ZMF sticker on it. It's a waterproof travel/storage case which should do an excellent job protecting your precious headphones with foam lining as well as thick pluckable foam sheet which is cut out to the headphone's profile. Accessories will likely be placed separate from the headphones to prevent any scratches in transit.


Accessories included with the Caldera are relatively simple yet meaningful. You get a couple of quick start guides walking over the unboxing experience, fitting the ear pads and cable, adjusting for comfort, and maintenance of the headphones over time. Then there are the headphone cables chosen and these come in a ZMF-branded soft cloth drawstring pouch.


If you opted to purchase additional ear pads or a tuning mesh—more on this thing later—then they will ship separately. ZMF was also kind enough to separately ship me a few different Caldera ear pads and the mesh to try out and see how they change the sound presentation of the Caldera. I'll have a whole page talking about these later on, but note how the pads come in bags that seem specifically made for them, including with the markings on the front for easier identification.