ZMF Caldera Closed Headphones
ZMF CALDERA CLOSED HEADPHONES REVIEW
Oscar Stewart first reviewed a pair of ZMF headphones last year, the excellent Ori 3.0, and in this review, he will be looking at their Caldera Closed. This model is a closed-back version of their popular Caldera, and it uses a planar magnetic driver along with a few proprietary tuning bits.
They are not a new model but, they are a popular headphone and cost $3499,99 / £3199.00 in their standard form.
BUILD AND FEATURES OF THE ZMF CALDERA CLOSED
All ZMF headphones are hand made in the USA, and they all have a similar level of build quality – and it is that of a tank. These are hefty headphones, ZMF sometimes call them heirlooms, as with care they will easily last forever.
The cups on this pair are made from Shou Sugi Ban Ash (Shou Sugi Ban, or yakisugi, a traditional Japanese technique of charring ash or other wood to increase its durability, making it naturally resistant to fire, rot, and insects. The process, often applied to ash for a striking, textured look, involves burning the surface with a blowtorch, wire-brushing, and sealing with oil. The finish is gorgeous in the flesh, and wood is known for its natural ageing and durability; the most recent model now comes in Zebrawood.
The headband frame is metal, and covered in genuine leather (vegan leather is an option at checkout), the same goes for the earpads. This mixture of metal, leather, and wood, with detachable mini-XLR connector cable, means these are designed to last.
The solid build quality does come at a bit of a cost, that is, weight; these are not the lightest of headphones, and as such, they can become a little uncomfortable after 2-3 hours of constant use. ZMF do sell a wider headband strap, which helps here, but there is no getting over the fact that these are on the heavier side. Luckily, the earpads are plush and deep, and the use of a comfort strap over a solid headband does help to ensure they are as comfortable as possible for their weight.
These use a planar magnetic driver, with patented ADS Damping system, patent-pending pad design, and Caldera magnet systems. They have an impedance rating of 60Ohms; however, they are rated at 94dB/mW sensitivity, so it is recommended to use them with a good headphone amp (they are quite power hungry).
The design allows you to change the earpads easily, and ZMF have a wide range of earpads, which can be used to fine-tune the sound to your liking. The same goes for the foam underneath the earpads; this can be changed to further tune the sound. For this review, stock earpads and foams were used, along with the stock cable, which is rather nice for a standard cable.
SETUP AND USE
As mentioned, these are stock and will be reviewed based on their out-of-the-box setup with standard cable and earpads.
I used them with my reference amp, the iFi iCAN Phantom (in solid-state mode), fed via XLR cables from my S.M.S.L D6S DAC. I use Roon with a mix of streamed music and local FLAC files from CD rips.
I also used them off the ZMF Aegis to test their synergy with SET amps (I also used them with the Cayin HA-6A MKII whilst testing, before writing this review).
SOUND QUALITY
ZMF have taken their excellent Caldera open, and put it in a closed back design (which is no simple feat), it offers up a sound that is slightly closer to the Harman curve that many people love. This isn’t to mean they have done what Dan Clark does, and made a headphone that is tuned to the Harman curve – this is still very much a ZMF tuning, and I love them for that.
ZMF don’t trouble themselves with perfect graphs or numbers; they make headphones that are both beautiful in looks, as well as subjective sound quality. This is easily present when you listen to the Caldera Closed – they simply deliver a sound that is more spacious, natural, and open, compared to pretty much any other closed-back headphone I’ve used.
Most of the time, I tend to start with something a little heavier, yet here I just had to write about the song Clandestino, by Deolinda (live recording, at the Lisbon Coliseum). I’ve mentioned this Portuguese fado band before whilst reviewing, and this track stood out to me through these. The live recording gives the song a huge space, and these headphones do that justice. They throw out a wide and deep soundstage, with each individual instrument perfectly placed within the soundstage. The vocals, well-centred, have a wonderfully natural tonality to them, whilst the double bass plucks are both articulate and deep. The whole song is beautifully presented through the Caldera Closed, transporting you into the room with the band, a feat reserved for headphones of this upper echelon.
Next up, some folk rock, in the form of Svea by Myrkur, and, once again, the Caldera Closed gives you a natural and unforced delivery of the recording. The drums have impact; they hit with authority and dig deep into the sub-bass with great rumble. The vocals are articulate and clear, whilst the strings add presence, and there is a coherent sonic image with impeccable clarity.
I Can Never Say Goodbye by The Cure is quite a slow, melancholy song from their latest album, and the mastering of this album gives it quite a heavy, thick, distorted sound. These headphones deliver the heavy drum beats with tactile punch, the distorted guitars sound gritty, and there is a rather bleak overall tonality that is clearly communicated through these. Robert’s vocals and harmonies have an air around them, and this is possibly the best I have heard this song. It has that heavy, morose sound, whilst remaining totally clear and accurate to the source. The last verse was delivered with such heavy emotion; it had me on the verge of tears.
One last track on this solid-state amp. Bon Jonah by Hot Mulligan is a more upbeat pop-punk song with quite a distinctive vocal character. The headphones sound honest and natural, with a slight dose of added body. They have great energy, which gets you bopping along, whilst delivering plenty of insight and detail. There is plenty of air between instruments, the bassline is driving and articulate, kicks have good body, and the vocals come across smooth, without sounding overly coloured. The treble is very impressive on these; they never come across as bright, yet there is plenty of sparkle and excellent extension up top when called for. I like how the panned guitars come across in this track, through the Caldera Closed, they give them great width, and these are closed headphones that sound impressively open and spacious.
Now I decided to use the ZMF Aegis for the last track of this review, and let’s make it a heavy one. The Orphan by Paleface Swiss is a band with surprisingly good recording quality for a metalcore band. The Aegis (with stock valves) gives these headphones a kick up the proverbial backside. Drum hits have more substance and heft to them; the thick bassline is distorted and expertly articulated. Vocals have impressive presence and clarity, guitars are powerful and well-positioned in the soundstage, snares are snappy, and cymbal crashes are crisp and clean. Whilst these headphones sound great out of a reference solid-state amp, plugging them into a quality SET valve amp such as the Aegis does transform them. The Aegis gives them a bit more of that valve goodness than the slightly tighter and more controlled Cayin HA-6A MKII, though you can tune both with your valves of preference.
QUIBBLES
Much like the Ori 3.0, my only slightly quibble is the weight, which is justified by the tank-like build quality, and well cushioned earpads.
CONCLUSION
The Caldera Closed are an exquisite headphone, but they don’t give you a closed-back feeling when using them, and provide a much wider sound than you would expect. They are remarkably well behaved, yet want to have some fun when called for, seamlessly bringing out subtlety in softer tracks, as well as delivering crushing breakdowns in metal without breaking a sweat.
The tuning is tastefully warm; it’s not a heavily coloured sound, yet there is an extra dose of warmth and body that prevents these from ever sounding thin. They are also revealing, both of source material, as well as amplification; whilst a reference solid-state amp can make them sound great, pair them with a powerful SET valve amp and they transform into something quite remarkable.
These are by no means cheap, but the performance they give, along with the build quality, more than justifies their price. I’ll grab these over my Susvara if I’m looking for a slightly more engaging listen, that’s for sure.
AT A GLANCE
Build Quality And Features:
Built like a tank, with easily replaceable parts
Easily tuneable sound with plenty of earpad options from ZMF
Sound Quality:
Open and spacious
Engaging, slightly full, and super punchy
Detailed across the board, with quite a revealing nature
Value For Money:
You get a lot of headphone for the money, even though they are not cheap
We Loved:
The build quality, the finish, and the excellent sound quality
We Didn’t Love So Much:
The weight of the headphones
Elevator Pitch Review:
These are not as bombastic as the Ori 3.0, yet not quite as neutral as the Susvara; they straddle a middle line of being crisp and detailed, whilst retaining a great sense of punch and energy when called for. These work with a variety of amps, my personal favourite, though, was the ZMF Aegis – there is an incredible synergy here that brings out the best in the Caldera Closed.
A highly enjoyable listen, and one that I reach for a lot when wanting to listen to my favourite music.
Price: £3199
Oscar Stewart
SUPPLIED SPECIFICATIONS
- Impedance: 60 Ohms
- Driver: 2 um thick Planar Magnetic with CAMS Patent Pending technology
- ADS Patented Damping System
- Caldera Patent Pending Pad Design
- Weight: 500-560g
- Sensitivity: ~94dB/mW
