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ZMF Caldera Oak Open Back Headphones | Audio Emotion
ZMF Caldera Oak Open Back Headphones | Audio Emotion
ZMF Caldera Oak Open Back Headphones | Audio Emotion
ZMF Caldera Oak Open Back Headphones | Audio Emotion
ZMF Caldera Oak Open Back Headphones | Audio Emotion

Product Description

Full Review : ZMF Caldera 

Caldera - ZMF's first proprietary planar magnetic headphone.

In 2011, I modded a t50rp as a gift for my brother. I never would have guessed that twelve years later I'd design my own planar magnetic headphone. I knew I loved the punchy, ethereal and nuanced sound of planars. Through modding a couple thousand t50rp's into different models and tunings for enthusiasts, my "schooling" had begun, and now years later - I'm proud to present the Caldera. For the full story, check out our YouTube Video on the Caldera.

Caldera is a type of massive volcano - we are using the Volcano theme because the new CAMS (caldera Asymmetrical Magnet structure) Patent Pending Magnet structure is shaped like a volcano/mountain on one side. This shape allows air to naturally spread out, and maintains a slightly asymmetric magnet force that makes the membrane more nodal, pushing a massive amount of air towards the ear and diffusing it at the same time. In concert with the also Patent Pending Atrium damping system which is also used on the Caldera, you get a linear frequency response, with a massive amount of punch, weight, and natural tones that ZMF is known for for the listener.

Aside from the new tech, we have a new earpad design for the Caldera, with what we will probably call Caldera Pads, which have a "fluting" from a smaller size on the driver size, to a larger size on the ear side. It's similar to the shape of the Audeze pads on the LCD 5, but will be more "flat" on the ear side like a volcano, This pad shape enables sound to retain air pressure on the baffle/headphone side, and for the ear cavity to still feel very open naturally. We will have three depths of these pads, and also will introduce Cowhide into one version of them, as cowhide pads can work brilliantly with planars.

The Caldera has an 80mm driver size, impedance is 60 ohms, Sensitivity is 95 dB/Mw. The baffle is made from true carbon fibre for weight.

Sonically the Caldera takes a lot of the ideas that started when ZMF was a T50 modding business, which a lot of those new to ZMF may not know about. It expands on the explosive, easy going sound that the Blackwood and Ori brought to the t50 arena, except with a more evolved sound and current tech.

When you think of the sound of the Caldera, it's BIG, with an adaptable stage like the Atrium, but loads of weight and control that comes with typical planar dreams, but the mid-range and treble stand out because of the ZMF damping systems and airflow of the magnets, it's more lucid and nimble, reminiscent of a great dynamic headphone.

I did reference the harman curve for parts of the tuning, specifically the 1.5 to 4khz area and made "some" decisions based on that, but I would NOT categorise this as a harman tuned headphone, just one where I was conscious of it in regards to midrange performance.

The current stock wood for the Caldera is American Oak. The Oak is finished in either a natural/black cup/grill combo or a coffee gold varnish and grill colour.


  • Natural or Aged Oak Caldera
  • ZMF Stock Braided Cable and OFC Cable
  • Choose your cable option between :
    • 6.35mm (1/4") OFC Cable + 4-pin XLR Stock Cable
    • 4-pin XLR OFC Cable + 6.35mm (1/4") Stock Cable
  • ZMF Caldera and 1 set of your choice
  • ZMF Owner's Card
  • Lifetime Driver Warranty


Impedance 60 Ohms
Driver 80mm with CAMS Patent Pending technology
Weight 490 - 550 (weight varies depending on Chassis)
Sensitivity ~95dB/mW

Headphones may vary from sample photos due to natural wood variance.

Caldera Tech and Info

Visit the ZMF site for full details -


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Delivery Information

Delivery is free for all orders over £250.

'In Stock' items ordered before 1pm will be dispatched the same day.

We use DPD Local 'Next Day Service' for most UK deliveries. Orders sent via 'DPD Local - Next Day Service' will be fully tracked with a 1-hour delivery timeslot on the day of delivery. Standard delivery is Monday to Friday.

Saturday delivery can be selected at checkout for £19.95.

Small items and LP's may be sent using Royal Mail.

Large/heavy items may be sent using TNT Express.

For all other countries please visit the 'Delivery Information' link in the footer.

Occasionally, due to stock demand, we can sell out. If this occurs when you make a purchase, we will inform you quickly. Most out of stock items are available for dispatch within 3 working days. If your purchase is urgent, please contact us to check availability.

Customer Reviews

ZMF Caldera American Oak Open Back Headphones



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Customer Reviews