Verdict
The HEDDphone TWO GT open-back, over-ear, wired headphones represent the best current performance from emerging headphone brand HEDD, and are glossy adverts for its proprietary, innovative AMT driver. While not one for ‘bassheads’, they offer superb insight alongside a compellingly fast, dynamic and natural sound
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Highly detailed, natural and precise sound
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Crisp, hard-hitting bass and treble
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Pleasantly warm midrange
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Reassuring build quality
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Choice of earpads, cables and adaptors
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Their physical weight can be felt over long listening periods
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Can’t plunge to bassy depths
Key Features
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Review Price:
£1899
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Sound
Air Motion Transformer (AMT) driver
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Generous accessories bundle
1.6m cable with 4.4mm jack, 6.3mm-to-3.5mm adapter, 4.4mm-to-XLR 4-pin adapter, carry case, leather earpads
Introduction
It isn’t every day, or even every year, that I come across a unique audio product, let alone a unique pair of headphones, and yet the HEDDphone TWO GT are unlike any headphones I’ve heard before. This is primarily due to their proprietary Air Motion Transformer (AMT) driver.
While headphones (and loudspeakers, for that matter) typically use transducers with piston-like diaphragms that move in and out to push and pull air in a 1:1 ratio, such as the widely used dynamic, planar magnetic electrostatic types, the AMT has a folded, accordion-like ribbon diaphragm that, instead of moving backwards and forwards, squeezes air out from between its pleats, laterally, at four times the speed that the driver is moving.
This air velocity, direction and efficiency, plus the lightweight and large surface area of the diaphragm, means the driver can deliver fast transient response, lower distortion and a well-imaged soundstage. In another words, a sound that is typically clear, crisp, clean and dynamically fast, with smooth, airy highs.
The AMT is not a contemporary innovation, having been invented as a tweeter design in the 1960s by the late American/German physicist Oskar Heil, and, in the following decade, deployed commercially for the first time in ESS’s AMT1 speaker.
Today, the AMT tweeter is commonly used in speakers from MartinLogan, GoldenEar, ELAC, Dali, Audiovector and others. It’s behind some of the sharpest, most attacking treble I’ve experienced. But what is novel is its deployment in headphones. In fact, Germany’s HEDD claims its inaugural HEDDphone model, released in 2020, was the world’s first full-range AMT headphone.
So how did AMT technology make its way into a headphone? Humour me in attempting to pack a 50-year story into a ‘SparkNotes’-esque summary. In the 1980s, HEDD’s co-founder, Klaus Heinz, then a young physicist and hi-fi dealer, was introduced to the early AMTs and, excited by what he heard, approached Heil with a vision of producing a revised and more compact version that could replace the popular one-inch dome tweeter.

When Heil’s patent expired, that vision could be realised, and the result was the Accelerating Ribbon Technology (ART) tweeter, which comprised neodymium magnets and a light, flexible Kapton film diaphragm, and debuted in pro speakers by Heinz’s ADAM Audio.
Fast forward 15 years, and Heinz founds HEDD with his son, mastering engineer Dr Frederik Knop (now CEO). AMT-featuring studio monitors are the initial focus, but then, in collaboration with Dmitry Grigoriev (now head of R&D), they create an AMT driver specifically for headphones, the ‘Variable Velocity Transform (VVT)’.
While the diaphragm folds in speaker AMTs need to be the same shape, in the VVT they vary in width and depth, supposedly allowing the driver to, according to HEDD literature, ‘achieve even frequency response across the entire audio spectrum’.
The aforementioned debut HEDDphone was born, designed to live in both the studio and home, and now we are two generations on with the HEDDphone TWO GT, which the German brand is calling its ‘first-ever’ hi-fi (or ‘audiophile’) headphone.
Specification
- Revised AMT driver with less distortion and warmer tuning
- Generous cable and earpad accessories bundle
- More affordable version with fewer accessories also available
Or, let’s say, a generation and a half on. This latest TWO GT is a revision of the TWO, which launched in 2023 and built on the original model with a tweaked AMT design and tuning, reduced weight and a new headband design.
The ‘GT’ refines that driver again, this time by applying a coating material to stiffen the folds so that the diaphragm moves more in unison, reducing distortion by a claimed 10%.

The tuning is supposedly warmer, too, and in the rather substantial box (I’ve been sent furniture in smaller couriered cardboard packages) is a generous accessories bundle that includes a hard-shell carry case; a second (leather) set of earpads; two 1.6m cables (one unbalanced, terminated with a 6.3mm jack; the other balanced, terminated with a 4.4mm jack); an 6.3mm-to-3.5mm adapter; and a 4.44mm-to-XLR 4-pin adapter.
HEDD has since released an ‘UNPLUGGED’ version of the package (£1499 / $1699) that simply includes a carry case, realising that some potential buyers may prefer to use other cables.
Finally, the cable – a hand-braided and nylon-woven, 4-core silver-plated copper type – is superior to that bundled with the ‘standard’ TWO, while an 8-core oxygen-free copper cable is also available separately for £529 / $659.

Design
- Lighter than before… but still a burden on the head
- Comfortable earpad clamping pressure
- Quality construction, right through to the cables
There’s no two ways about it – the HEDDphone TWO GT give off the kind of first impression any parent would hope for from a potential future son/daughter-in-law. Inside the substantial box is a nicely presented box of cables, adaptors and leather earpads, and another in which you’ll find the fabric-wrapped hard-shell case and, inside, the headphones.

Everything screams ‘quality’, and the package isn’t bereft of the small touches that show HEDD has thoughtfully considered what a £1899 / $2199 package should look and feel like. I like, for example, that the case has an integrated compartment for housing some of the accessories, should you wish to travel with them. It therefore didn’t surprise me to read that the kind of care taken to assemble the headphones in HEDD’s Berlin premises extends to folding the Kapton diaphragm film by hand.
The size, weight and build quality of the headphones themselves inspire confidence, too. The carbon-fibre and magnesium housing seems durable and smartly finished, while the easily removable sets of lamb leather and velour (my personal preference) earpads are equally plush.

Considering my reference Grado headphones weigh 40% less than the TWO GT, it did take a couple of listening sessions to get used to their 550g bulk. HEDD has significantly reduced the mass from the 730g originals, presumably due to customer feedback, but even so, they still make their presence known, and no amount of headband tweaking eliminated the pressure enough for me to wear them for longer than an hour and a half at a time.
The patent-pending headband, which can be adjusted via a strap that you can pull or relax to fasten to a clasp, does allow a decent amount of alteration for various head sizes and clamping preferences, though. This is perhaps the one design element I fear might become worn over time, should the fastening holes become stretched, but it’s worth noting that the HEDDphones come with a five-year warranty.
I found the earpads’ clamping force ideal – not ‘head-squeezing’ tight or ‘danglingly’ baggy. For the duration of a couple of albums, the TWO GT proved perfectly comfy.

Sound Quality
- Open, spacious, clear and fast
- Hugely revealing
- Not for bassheads
Were it not for my precious noggin, I could have listened to the TWO GT all day. Their sound is instantly likeable; akin to electrostatics in their typically outstanding openness, clarity and speed. Despite them taking a while to warm up and lose their out-of-the-box sharpness, within seconds of listening I knew I would be reaching for my favourite songs during my time with them.
The vast expanse of their soundstage, and how it’s evenly and precisely peppered with fine detail and expressive dynamics, really draws you into recordings. The treble bites; the midrange is transparent and natural sounding, with a slight warmth tinge; and the bass, while not able to plunge to the lowest depths, is pleasingly textured and agile. Individually, each is impressive, and together they make for a compelling presentation.

Play the 2000 recording of Joni Mitchell’s Both Sides Now, and the dynamic attention given to the opening flurry of strings, woodwinds and harp is impressive, the emotional intention behind the swell of orchestration well carried. And then her beautifully mature, jazz-inflected vocal glides over the top, and the TWO GT’s warm, revealing midrange is full of feeling. They grasp her sentimental delivery with both hands, effortlessly tracing its ebb and flow and rising to the occasion during its – and the orchestral – climax. Rarely have I heard the solo sax soar so potently through the sweeping instrumentation.
Changing genre entirely, I play Mura Masa and slowthai’s Deal Wiv It, and it’s a glossy advert for the HEDD’s strengths. The bassline thumps and the beat snaps, underpinning the rhythm and propelling the track forward, while the punky rap is full of its dynamically elastic, playful energy. The chorus’ chopped vocal samples are just as explicit, and the bright, filtered guitars play into the TWO GT’s lean, fast temperament.
These aren’t warm, weighty, smooth headphones you can put on and forget about; the HEDD’s sonic presentation is as striking as its physical one, and all about presenting the detail in and intent behind music. Their forward edge and relatively lightweight bass might not be for everyone (want to feel the sub-bass in Billie Eilish’s bad guy? Forget it). But it’s hard to argue with their compelling resolution and agility. Rarely have I come across such insightful headphones at this level.

Should you buy it?
Clean, clear and dynamic sound
You want open-backs that are exceptionally clear, detailed, fast and dynamically expressive, and would also benefit from both unbalanced and balanced cables. If you have your own quality cables, consider saving money by purchasing the ‘UNPLUGGED’ package instead.
Open-backed headphones aren’t for you
You would prefer the isolation of closed-back headphones, like a ‘basshead’ presentation, and/or are seeking ultimate comfort for frequent long listening sessions.
Final Thoughts
HEDD CEO Knop says that one of the company’s biggest goals is to evolve into a leading-edge headphone manufacturer over the next few years, and it’s going the right way about it.
A glorious advert for its proprietary AMT driver and attention to design detail, the HEDDphone TWO GT are among the most accomplished performers at their price tag.
If HEDD can continue down this path, iconic status in the head-fi world wouldn’t be beyond them.
How We Test
After running in the TWO GT for over 24 hours, I tested them in my desktop and hi-fi setups, connecting them to a Chord Hugo 2 DAC (fed by a laptop playing Apple Music) and a Marantz PM-KI Pearl Lite (fed by a Cambridge CXN V2 streamer), respectively.
I tried both pairs of supplied earpads, and used my comparatively more affordable reference headphones, the Grado GS1000, for comparison purposes.
FAQs
The £599 D1 is also an open-back headphone from HEDD, but it is a completely different beast from the ONE, TWO and TWO GT, featuring a more traditional dynamic driver as opposed to an AMT one. Its driver has a thin-ply carbon diaphragm to encourage a cleaner, faster sound than typical dynamic designs, however.
The headphones in these two packages are the same, but the ‘UNPLUGGED’ version contains only the headphones and carry case; you don’t get any cables or a second (leather) set of earpads.
Full Specs
| HEDDphone TWO GT Review | |
|---|---|
| Manufacturer | – |
| IP rating | No |
| Weight | 550 G |
| Release Date | 2026 |
| Driver (s) | Proprietary Air Motion Transformer (AMT) |
| Connectivity | 1.6m hand-braided, nylon-woven, silver-plated copper cable with 6.3mm jack |
| Frequency Range | – Hz |
| Headphone Type | Over-ear |
| Sensitivity | 88 dB |
| UK RRP | £1899 |
| USA RRP | $2199 |


















