In today’s feature, we review the Dan Clark Audio EXPANSE which is a flagship open-back 4th gen planar magnetic driver headphone using AMTS. It is priced at $3999.99.
Disclaimer: This is a sample sent to us is a sample in exchange for our honest opinion. Headfonics is an independent website that does not have any affiliate links or status. We thank Dan Clark Audio for this opportunity.
To read more about Dan Clark Audio products we have previously featured on Headfonics click here.
Note, this review follows our new scoring guidelines for 2021 which you can read up on here.
As sure as night follows day, Dan Clark Audio has followed up their flagship 2021 closed-back Stealth headphones with an open-back ‘brother’ called the EXPANSE.
I say ‘brother’ because from afar and on a high level the EXPANSE seems like a double take of the Stealth. And indeed, both share a lot of innovative features such as DCA’s Acoustic Metamaterial Tuning System and that unique foldable form factor.
However, that only tells half the story here. Quite apart from the acoustical changes from going open-back, DCA has also taken the opportunity to tweak the tuning of that 4th gen driver to suit as well as introduce some very unique and nuanced design motifs.
As a result, the EXPANSE is a very different-sounding beast to its closed-back sibling and a competitive alternative in today’s burgeoning flagship headphone market.
Tech Inside
Driver
The Dan Clark Audio EXPANSE is an open-back planar magnetic headphone and one that leans on the use of that new 76mm 4th gen driver first seen inside the Stealth last year.
This is a single-sided V-planar driver and one that is almost 20% larger than the previous version inside the Ether 2 and the Ether C Flow. It also has the thinnest diaphragm DCA has created to date for its drivers.
It uses 11 magnets per channel positioned to the outside of the driver inside a very heavily damped enclosure rather than the inside of the driver as was the case with the open-back Ether 2.
From what I am told the new tensioning system used to help create that very thin diaphragm also helps to improve distortion control and driver matching with a lower tolerance parameter than before.
DCA has stated previously they measured the Stealth at around 1/4dB or less inside the actual headphone enclosure and not free-standing so I have to presume something similar for the EXPANSE also.
The driver is rated with a nominal impedance of around 23Ω with a sensitivity rating of approximately 86 – 87 dB/mW so like the Stealth the EXPANSE is going to thrive on quality power.
AMTS
The EXPANSE also retains the Stealth’s innovative AMTS or Acoustical Metamaterial Tuning System which sits inside the cups one per side.
However, given its key strength in terms of waveguide manipulation and diffusion control, this will not be the exact same resonator frequency arrangement as the closed-back version. The key to creating a natural and immersive soundstage is quite different within an open-back environment compared to a closed-back.
The AMTS secondary technical principle means that it will still double up as both a programmable Helmholtz or quarter-wave resonator to control those high-frequency standing waves and resonance via the ‘ramped’ shaped design. This version starts at 5kHz at the peak of the ramp and down to 20kHz at the base of the ramp.
Thus, the programmable aspect of EXPANSES’s AMTS allows DCA to change the structural waveguides with different blocking arrays, and the high-frequency damping levels are adjusted as a result to match both the changed acoustical environment and the new tuning requirements within.
Dan has often considered these tweaks as a type of advanced level of acoustical treatment. A system by which to smooth out high-frequency unevenness or excess energy circulating in the smaller inner cavity of the earpads without any loss in resolution.
Design
The sleek elongated half-gimbal form factor from the Stealth has been retained but the aesthetics look stunning on the EXPANSE, perhaps even more so compared to the closed-back visuals.
As with the Stealth, the materials are a mix of high-class USA vat-dyed leather, vegan suede, and titanium nickel, (Nitinol), for the svelte headband structure.
However, the first thing you are likely to comment on is the new open-back cup concave grill visual which is formed from intricate generative design patterns based on mathematical formulae.
That means those undulating circular formations are very unique and probably unlikely to be duplicated with ease. They also feel quite sturdy to the touch so I would not be too concerned about their potential to snap or crack.
DCA has also retained the Stealth’s wider padded protein leather adjusting strap but changed the aesthetics to more of a blue tone than red this time around. Without the need for limiting adjuster blocks, those Nitinol rods are wider-spaced compared to the narrower AEON bands.
Tied in with the teardrop shape, those integrated hirose connectors, and that elongated anodized aluminum grill frame give the EXPANSE a bit of a mecha vibe. Even more so when you fold the headphones down to half their size.
I honestly do not think there is a flagship planar headphone out there that articulates quite as well as the EXPANSE does in that regard.
Comfort
Having used the Stealth for over a year now I kind of knew what to expect with the EXPANSE comfort levels. I wasn’t disappointed would be an understatement because it’s right up there with the likes of the Meze Elite and Empyrean as some of the most comfortable headphones out there.
Yes, at 415g it is not the lightest out there, not even compared to the older ETHER 2 at 380g. However, the ovoid cup shape combined with the excellent vertical and lateral pressure balance makes this a very steady headphone that easily clears your ears and provides super comfort in the process.
Despite the cup weight bias, the EXPANSE clamping compensation is not overly noticeable due to the comfortable pad design combined with that self-adjusting wide pressure strap. You will not get any scalp hotspots with the blue thread quilted padding design underneath nor feel any unnecessary downward pull on the top of the ears.
Add the hybrid velour finish on the contact surface of the ear pads into the mix and you also lengthen the listening time without any annoying heat or sweat build-up in the process.
Something I do not normally talk about with an open back is isolation but I will make an exception here. The EXPANSE isolates better than your average open back with an unexpected degree of attenuation on background noise. Not to Stealth levels but if you are pitching it against something like the Susvara you will notice a difference.
Stock Cable
DCA sticks with the angled Hirose connector system and throws in the VIVO Super Premium cable as stock with the EXPANSE. The VIVO Hirose connectors are also a setup from the DUMMER cable versions noticeable by their very precise connection clicks compared to the slightly mushier-sounding DUMMER lock.
The VIVO cable is a silver-plated OFHC copper wire available in 1.1m, 1.8m, and 3.1m lengths with the 3.1m length carrying a $50 premium.
The VIVO uses a better geometry than the DUMMER to minimize both capacitance and inductance so it is a bigger cable overall. However, it is very pliant with no memory retention, (kinks and twists), and zero microphonics.
The weaved cloth jacket remains the same on both however the Y-split divider is much improved with an aluminum alloy barrel compared to older heat-shrink rubber from older cable generations.
The connection options for the VIVO are wide-ranging. DCA sent me the 4.4mm version for this EXPANSE sample but you can have 6.35mm, 2.5mm TRRS, 3.5mm TRS, and 4-pin XLR, depending on your needs.
Packaging & Accessories
The format for the EXPANSE packaging is the same as the Stealth but I can’t help but feel slightly disappointed by a reversion to formed cardboard for the outer box whereas the Stealth has a very cool leather-finished display design.
I believe rising production costs (like everything in 2022) put paid to that Leather box. I would have loved to have seen a blue stitched version of the leather box to complete the visual. Once unboxed though the experience is very similar.
The headphones are in their folded position inside a larger more refined version of the diminutive AEON hard-shell case with a nylon external finish and the EXPANSE emblem on top. To protect the drivers, DCA has placed a substantive foam layer as well as a stopper between the two earpads.
This case is then neatly inserted into a protective display tray with the cable and warranty cards neatly wrapped in matching colored cardboard at the base of the tray. Simply slide it out and open it up to access the cable.
