We review the ZMF Headphones Atrium Closed, which is a closed-back circumaural dynamic driver headphone with a bio-cellulose diaphragm. It is priced at $2499.
Disclaimer: This sample was sent to us in exchange for our honest opinion. Headfonics is an independent website with no affiliate links or status. We thank ZMF Headphones for this opportunity.
You can click here to learn more about the ZMF Headphones products we have previously covered on Headfonics.
Note, that this article follows our latest scoring guidelines which you can read up on here.
ZMF Headphones like their variations. When you work with wood you can vary things a lot so it’s no surprise that not only do we have a closed-back version of last year’s excellent dynamic driver Atrium but we also have it coming out in a couple of wood variations.
Zach and the team have done the open and closed alternative before with the Verite so we should not be surprised the Atrium will have an Atrium Closed sibling also.
Not only one sibling but a second will be released at the same time using a very different style of wood called the Atrium Closed LTD.
Both the open and closed-back versions are second only to the flagship Caldera with similar pricing schemes at $2499 for the stock edition with the LTD retailing for an SRP of $2899. Until May 14th, 2023, both LTD and stock are being discounted by ZMF with $400 off the LTD and $300 off the stock.
I highly advise trying to grab the LTD if you can. Not only is it a very unique-looking headphone with a shorter production run but it also sounds a bit different to the stock. You can flip over to page 3 of our view to understand why.
Tech Highlights
Driver
The Atrium Closed driver is unchanged from the open-back variant save for sitting a little further back in the cup. This is still a 50mm dynamic driver using a composite bio-cellulose diaphragm surrounded by N52 rare earth neodymium magnets and rated at 300Ω.
Bio-cellulose itself is a well-known lightweight material for diaphragm construction and is derived from a naturally grown organic compound that tends to be a bit stiffer than your regular paper alternatives.
Hence the use of a powerful magnet system and a 300Ω rating for the Atrium means you need a capable amplifier to properly drive the diaphragm’s excursion to the required level.
Gradual Diffusion
What has changed is the way the Atrium damping system has been implemented to accommodate the associated acoustical response that comes from using a closed-back design as opposed to an open-back. This is a malleable technology that can be adjusted to suit the driver and acoustical space format.
The key to this is diffusion, or as ZMF describes, the concept of gradual diffusion to eliminate the potential for standing sound waves. These are nodes of opposing levels of intensity but from the same frequency that tends to cancel each other out and something that can raise its ugly head in closed-back designs.
This time the damper and associated multi-weighted materials are distanced in such a way that it creates space between it and the driver that, combined with the asymmetrical cup structure, allows for better or a more natural type of sound wave diffusion.
ZMF has also introduced some new modified Caldera thin pads, with a slightly fluted design and thinner on the inside with less surface area to give the Atrium Closed a more open-ended experience. The new pad shape and their external venting patterns further diffuse the sound when combined with the damping system for additional impact.
Design
Aesthetics
The stock Atrium Closed uses the same softwood cherry wood cup material as the Atrium open-back version but aside from being a completely closed cup save for a small venting slot on the side, the aesthetics look very different.
This particular version is a dark mahogany-aged cherry finished with some beautiful-looking coffee gold adjusting rods and is one of two stock options you can buy.
The other stock option is the natural grain of cherry wood which bears a closer resemblance to the Atrium Closed back sample we reviewed last year with its light colors and grain.
The ambiance of the mahogany-aged cherry wood is darker with a stronger ‘brushstroke’ type of grain all over and slightly less of a glossy overtone compared to the natural cherry version. You can feel that differing finish by running your hand over the wood cup and feeling just a shade more tactile friction in doing so.
Because it is a closed cup there are far fewer venting slots with just a tiny 7mm slot on each cup combined with a discreetly positioned 1/16″ hole on the inner cup plate under the pads.
Materials
For the rest of the Atrium Closed design, the materials finishing is largely unchanged save for the new thinner pad designs.
That means a mix of anodized black aluminum for the pivot blocks and yokes, spring steel for the headband, and leather for the pressure strap and headband outer. The natural cherry wood option will also have the adjusting rods in a matching black finish as opposed to the coffee-gold on this sample.
You can also get the Atrium Closed in a lighter magnesium build which will take off 34g from the final weight. However, note the magnesium version is not anodized but rather painted so it might show some additional wear and tear over a period of time compared to the aluminum build.
Comfort & Isolation
The specs say a 10g difference in the weight between the Atrium Closed and the open-back version so the weight and form factor are virtually the same.
That does mean the headphone is more on the heavier side for a dynamic driver and close to planar headphone territory, however, the padding combined with the headband structure and pressure displacement makes the Atrium Closed a fairly comfortable headphone to wear for extended periods.
The (Crescent) strap and rod adjuster system gives you plenty of room for adjusting to varied head shapes and sizes for height.
The adjustable pressure strap system also tucks right into the very soft leather-wrapped memory foam on the headband reducing the potential for narrow contact pressure spots, one of my pet peeves with any poorly designed headband system.
With the Atrium Closed I tend to wear it with the notch up 1 slot from zero to give it a more secure fitting. Since it is a closed back it does isolate a lot more than the open version but that advantage will be lost if you loosen up the clamp.
The adjuster movement is still a bit notchy for me though and adjusting is still a two-handed affair meaning you have to take off the headphones to make micro-adjustments which is awkward.
Pad Choices
The fitting is still quite comfortable with a stronger clamp and much of that has to do with the new detachable stock ‘thin caldera’ pad designs which have a wider inner cavity and a slightly more fluted design.
That gives you a roomier feel for your ears and mitigates any unintended pressure from any enhanced clamping.
They also serve a dual purpose acting as an acoustic extension for the Atrium Closed gradual diffusion system with perforations on the outside of the pads to slowly dissipate the sound waves whilst the solid inner wall helps to retain the passive isolation performance typical of a closed-back design.
You also have the option of buying the Atrium Closed with the Caldera vegan suede pads or the Auteur solid suede option and these are slightly different in design though they do have the same external venting system.
The main changes as far as I can subjectively see are a slightly taller outer wall and a narrower inner cavity closer to the open Atrium pad opening size. Indeed, for sound impressions, the suede offers a different tuning characteristic with a less sub-bass presence, a more relaxed and open midrange, and a bit more treble sparkle on top.
Just a small side note on the acoustical properties of the Atrium Closed where the new pads are a factor and that is the removal of the mesh system found in the open-back alternative. Zach and the team found that the new pad diffused design or properties negated the need for either the Titan or solid mesh when tuning the headphones.
Stock Cables
The Atrium Closed comes with a similar stock cable lineup to the open-back version. That means two 5.5ft cables in both balanced and single-ended format with the balanced terminated with a 3-pin XLR and the SE with a 6.35mm jack.
The balanced version is an insulated copper wire with a nylon jacket outer in a twisted rather than braided build and finished with a black aluminum funnel-type splitter. The mini-XLR pins are terminated ‘Audeze’ style so their polarization is fairly standard.
The SE stock cable uses a 24AWG 4-conductor OFC copper wire with aluminum and copper shielding housed in a rubbery external jacket with the same black branded splitter and mini-XLR connectors. The 6.35mm barrel is wrapped in heat shrink with strain relief internalized.
My personal preference has always been the braided nylon jacketed balanced version simply because my preferred amps are also balanced. I tend to find the rubbery SE a little bit stiffer to use though both should not give you any issues in terms of detectable microphonics.
Accessories & Packaging
ZMF Headphones use some awesome weather-sealed carry cases for their headphones and the Atrium Closed is no exception. It is the same case as the Atrium open-back version but I have no complaints about that as they are very durable with very strong hinges and latches that can take plenty of knocks.
The insides have heavily padded ceilings and bases with the headphones themselves secure in the middle. Should you order additional pads they will come neatly tucked between the cup and headband with the accessories carefully organized at the base of the case.
My own sample did not come with much in terms of marketing collateral save for a cleaning cloth and the build or warranty ownership card but you should expect to receive a bit more such as the company brochure, pads selection, and a pads brochure similar to the Atrium open back package.
