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