HEDD Audio HEDDphone TWO GT - Official Thread

[taronlissimore]

Last year, HEDD Audio released the HEDDphone TWO and while there were some marked improvements in design and comfort, some felt the tuning just wasn’t what they were looking for. So HEDD spent the last year examing the feedback on the tuning of HEDDphone TWO and collaborated with respected audiophiles and the HEDDphone TWO GT was born.

From The Manufacturer

• From Pro to Audiophile: Introducing the HEDDphone® TWO GT.

Since 2019, HEDDphones have been trusted by artists such as visionary pianist Nils Frahm, iconic rapper Q-Tip, and Academy-Award winning composer Hildur Guðnadóttir (Joker, Chernobyl) to be reliable day in, day out. Audio Engineers like Heba Kadry (Bjoerk) and Tchad Blake (Arctic Monkeys, The Black Keys) celebrate them for their honesty and precision in the process of making records.

Now HEDDphone® TWO GT writes the next chapter in this truly unique approach to headphones, taking the speed and fascinating clarity of HEDDphone TWO’s Air Motion Transformer driver to the world of modern audiophile listening.

Performance is PLEASURE.

The GT is to the TWO, what a Gran Turismo is to a race car, more comfortable and certainly more forgiving. Whilst HEDDphone TWO was designed to be a cutting-edge engine to deliver fast and exceptional results for audio engineers and producers, the GT adopts the analytical clarity of the TWO, adding a warmer sonic signature and premium comfort experience. Every element of this high-performing product will enhance your ride.

The details you can HEAR.

Like its professional counterpart, HEDDphone® TWO GT uses a robust, yet ultralight multi-layered Kapton diaphragm that is over three times larger than traditional dynamic, planar or electrostatic driver designs. The new HEDD Air Motion Transformer utilises the latest Variable Velocity Transform technology and produces the lowest ever distortion levels in AMTs across the audio spectrum, from 10Hz to 40kHz. Therefore the driver allows for more accurate dynamics and an effortless soundstage.

We’ve combined substantial feedback from the passionate Head-Fi

community with our unwavering dedication to improve. The new air-

compliance tuning system creates impactful bass, alongside a warmer mid-range and sparkling top end to deliver the emotion within the music.

So, meet our Grandest Tuning to date.

The details you can FEEL.

The HEDDphone® TWO GT is designed for pleasure so get ready to lose yourself in your favourite album or playlist. We have engineered the clamping force on the carbon fibre headband to be more comfortable for longer periods, with softer ear pads and the unique dual strap system, that can be adjusted and fixed to your preference. To give our customers a choice between different comfort experiences without taking them away from the music, the new ear pads are finished in either velour or sheep leather. The improved cable quality adds to the overall luxurious experience.

The details you can RELY ON.

HEDDphone® TWO GT is all about high-end components & materials. We’ve designed it to be reassuringly strong. The lightweight magnesium chassis and carbon fibre HEDDband ensure comfortable extended or repeated listening experiences. We provide ultra high-purity copper cables and all the connectors you’ll need, so you can dive into your favourite music straight out of the box.

German engineering excellence.

HEDD Audio founder Klaus Heinz has been a pioneer of loudspeaker design for over five decades, including creating the modern AMT driver which is also the heart of the company’s unique headphone range. Our highly skilled assembly team in Berlin hand-builds every HEDDphone® to meet the highest standards of quality. Our pedigree in design and construction speaks for itself but we back that up with a 5-year limited warranty for every HEDD product registered by our customers.

Accessories.

The HEDDphone® TWO GT ships with all of the possible cables and connections you need to connect directly to your favourite amplifier.

Every cable is designed for rigorous use and made using a combination of high-purity, silver-plated copper in hand-braided nylon strands.

The included travel case provides a sturdy way to store and protect your

HEDDphone® TWO GT at home or on the move.

The details you can ADD ON.

GTC Premium upgrade cable for a better sound.

Designed specifically with the HEDDphone® TWO GT in mind, we have engineered the GTC Upgrade Cable for an even richer and more detailed sound. At 22 AWG thickness it provides lower impedance and unveils even more nuances in the audio. This high purity LC-OFC cable counts no less than 760 strands and requests the highest quality amplifiers to show their true potential. The GTC Upgrade Cable is also compatible with the original HEDDphone® TWO and will secure a podium finish in any high-end collection.

Technical Specifications.

• Concept: Open-back over-ear
• Driver: Full-range Air Motion Transformer (AMT) Diaphragm: Multi-layered Kapton polyimide film Frequency range: 10Hz – 40 kHz
• Sensitivity: 88 dB/W
• Impedance: 41 Ohm
• Weight: 550g
• Power Requirements: 200mW (minimum), 1000mW+ (recommended)
• Cables: High-purity and silver-plated copper with nylon braids
• Ear Pads: Velour and sheep-leather
• Each HEDDphone® TWO GT is proudly assembled in Berlin, Germany

Box content

• 1x HEDDphone® TWO GT
• Travel case for HEDDphone® TWO GT and Accessories 2x sets of ear pads finished in velour and sheep leather 1x unbalanced cable with 6.35mm termination (1.6m)
• 1x unbalanced adapter, from 6.35mm to 3.5mm 1x balanced cable with 4.4mm termination (1.6m)
• 1X balanced adapter, from balanced 4.4mm to XLR

If you’re at Canjam SoCal 2024 this weekend feel free to stop by the Headphones.com booth where we will have a couple of pairs along with the team from HEDD Audio to answer any questions!

[gzost]

It’s 2024. When a company announces a re-tune of a headphone, I expect measurements of the original and updated model, not just flowery prose.

[Hifiearspeakers]

Well said. Couldn’t agree more.

[DrHiFi]

First Impressions of the HEDDphone Two GT - A Draft of My Notes (originally posted on head-fi.org)

(22 Oct 2024)

I’m thrilled to share my first impressions of the HEDDphone Two GT, which I received as part of my pre-order from headphones.com. Many thanks to both HEDD Audio and headphones.com for the excellent customer experience they created! Just to clarify, I bought these headphones with my own money and have no affiliations. This is still a draft and raw set of notes, not an organized or edited review, but I wanted to share my initial thoughts for those on the fence about placing an order.

Out-of-the-box Impressions:​

Setup:
First listen through Qobuz → iFi Gryphon (USB connection, engaged XSpace and XBass-Presence only) → C9 (High Gain, class A, SS Mode, 4.4 mm input & output) with premium GT cables (I’ll discuss those later).

The sound is good—detailed, clean, and in control. However, if you’ve listened to headphones like the HE6se, HE1000se, Susvara, Utopia, or Sennheiser HD800S, the HEDDphone Two GT doesn’t immediately stand out as a revelation on this setup. I suspect a more powerful chain or some burn-in time will unlock their full potential. And yes, I believe in burn-in—whether it’s brain, pad, or driver break-in, I’ve always noticed improvements after some hours of playtime. I know it may not be measured, and if you’re wondering, I’m a scientist by profession and know what measurements mean and do not believe in pseudo-science, but I’m also a human who perceives things different than machines. That said, these have only been running for about 90 minutes so far, so it’s too early to make any final judgments.

*Note that using XBass on Gryphon all in when using the 4.4 mm output to C9, similar to many IEMs and headphones, you’ll hear distortion on many tracks.

Performance on My Full Desktop Chain:​

Setup:

• Source: Qobuz → iFi Pro iDSD Signature (USB input, stock tubes)
• Preamp: iFi Pro iCAN Signature (stock tubes) → Cayin HA-300MK2 (Elrog ER300B power tubes, 6SN7GT driver tubes, and NOS 22DE4 rectifiers)
• All XLR connections

This is where things get exciting. With 18dB gain from the iFi Pro iCAN Signature, the HEDDphones come alive. Every layer and frequency in TOOL’s Pneuma is beautifully distinct, and no frequency feels artificially emphasized. The brilliance range shines with a lush presentation, especially, with the tubes in the chain, I suspect.

The sound reminds me of the Susvara, though at a slightly lower technical level, IMO (but remember, they’re almost one-third of Susvara’s price). There can be more weight and impact in the low end—not from the Pro iCAN Sig’s XBass (though 10Hz is enough before distortion), but from the natural warmth of the tubes from both Pro iDSD Sig. and Pro iCAN Sig. It’s a fun, engaging listen, though slightly more fatiguing not only sonically (in dense passages), but also, unsurprisingly, physically as they’re clearly heavier than Susvaras (450g for Susvara vs. 550g for the GT). I found myself taking short breaks after a few songs.

Versatility and Chain Synergy:​

These headphones are versatile and analytical when needed. They excel with a full-powered desktop chain, but portable setups may struggle to do them justice. For example, The Relapse by Von Hertzen Brothers sounds much better when run through my preamp chain rather than direct RCA from the Pro iDSD Sig. Bass is phenomenal, and if your chain isn’t up to snuff, the HEDDphone will reveal it. As you progress through the track, the layers unfold, showing that the GT is exceptional for complex music.

The background is incredibly dark—similar to planar headphones—with a noise floor so low it even rivals that of many planars but also some high-end IEMs like the Sennheiser IE900. Listening to The Sound of Silence by Disturbed is a haunting experience. David Draiman’s vocals are ethereal, and the HEDDphones reveal every nuance in his performance. (*And yes, I prefer the album version over the live one, but that’s just me.)

For Electronic Music:​

They hold their own against most planar headphones, especially on the XLR output of my amp. I used HEDD’s stock 4.4mm to XLR adapter along with the Premium HEDD cables, which are terminated in 4.4mm. These cables are absolutely stunning. I’m not ready to claim they make a huge difference without direct comparisons, but paired with the XLR output, they open up the sound in a way that truly shows off the HEDDphone’s capabilities.

Final Thoughts (For Now):​

I’ve only scratched the surface of what the HEDDphone Two GT can offer. One track that stands out is Runaway by Aurora, which highlights just how professional these headphones are. HEDD has definitely tuned them with audiophiles in mind—adding a hint of fun to what is otherwise a very technical and neutral sound. They’re similar to other highly regarded headphones like the HD600, Stellia, or HE1000se (a.o.) in that sense.

While I haven’t heard the previous HEDDphones to make a direct comparison, I can confidently say I’m impressed and have no regrets about the purchase. These are serious headphones for serious listening, with more versatility than I expected. I’ll continue to experiment with different setups, cables, and tracks to fully explore what these can do, so stay tuned for more updates.

Thanks for reading!
Dr. HiFi

[Spearthrower_Owl]

Nice review, thanks for posting.

Does anyone have a frequency response graph (the squiggly lines)? I don’t regard their significance as paramount, but I do like comparisons. Supposedly the GT is a more V-shaped tuning rather than a midrange focus. Would love to see how this shows up on the rigs.

[listener]

Nothing that can be shared yet as we’ve not measured a retail unit, but the ones I heard at the show were very much so not V-shaped, maybe U-shaped is a better description.

Under 500 Hz, it has the same bass extension we’ve gotten to know from HEDD’s designs, but with a more generous low midrange presence. The reason I say its not V-shaped is because it has bang-on “HRTF correct” ear gain, and in this respect is more normal than most kilobuck (hell, most in general) headphones. It is slightly dark in the mid-treble depending on which pad you use—as it comes with both leather and suede—and then has a bit of emphasis in the 10-12 kHz area.

I think most people will be positively surprised with how good it looks on a graph, but even so I encourage all enthusiasts to reserve judgment on it until they get to hear one.

[Spearthrower_Owl]

Thank you! That sounds very promising. Like maybe even perfect based on how I hear. For clarity, mid-treble is ~6-10k? (I’ve always been a little fuzzy on where these lines get drawn.)

For amusement, here’s my conversation with chatGPT a minute ago:

[Resolve]

Here are the B&K 5128 measurements. I’ll need to also put up the comparison with the original Heddphone 2 as well but that is a task for tomorrow.

The pads are nearly identical - Purple is leather, orange is suede.

HpTF Variation (2 heads):

Leather

Suede

Not sure what this is?
Headphones behave differently on different heads. Everything from pad deformation, to the size and shape of the physical ear filling the space, to the way it sits on the head can all have an influence on the frequency response at the eardrum. If you’ve ever seen a graph and thought “but this doesn’t match my experience”, HpTF variation (headphone transfer function) is likely the reason why. And yes… this is also one of the key factors in explaining differences in perceived ‘technicalities’ among listeners, but that deserves its own separate topic.

So far we’re showing just two ‘heads’ with their own unique pinnae, in the form of the GRAS 43AG’s KB5000 and the B&K 5128’s pinna, but ideally we end up developing more to test on in the future.

[n1k1]

Wonder how this compares to the Heddphone Two EQ that was posted in the original review.

Looks almost bang on in the ear gain region with an additional midbass hump and more sparkle at the high end, but maybe more forward because of the bump at 1k-2k?

[Resolve]

Well we wouldn’t use the DF tilt as an EQ tool like that these days. That’s probably best used as an evaluative concept, not something to specifically target, particularly because of how things change from head to head.

[n1k1]

That makes sense, I was mostly curious about how similar the OG Two EQ’d would sound in comparison to the GT, especially since they have similar driver tech.

[Resolve]

Yeah quite similar if you EQ.

[Daiyama]

So if you EQ the OG TWO the GT is not really a must? Or do you hit any limits in the bass because of the EQ?

[Resolve]

I didn’t encounter any specific limits like that with either model.

[Daiyama]

Thanks.

So OG and GT is only a viable differentiation when someone do not want to EQ. If someone has no issue using an EQ both iterations are interchangeable or are there still unique selling points for each version?

[Resolve]

If you already own a HEDDphone 2 and you’re able to EQ it, I see no meaningful reason to get the GT. I think of it as two different tuning options, neither being categorically better for those of us who do EQ. But many people don’t, and for those people I’d recommend the GT over the OG.

[Spearthrower_Owl]

Just eyeballing these different graphs, I’m a little puzzled as to the basis for the manufacturer’s claim that the GT was designed to be warmer. It looks as if it should be a bit brighter, no? Or maybe these two graphs aren’t “apples to apples”?

[Resolve]

The GT has considerably more bass, but also more ear gain. So it’s true, but it’s like… also with more clarity.

[Spearthrower_Owl]

Thank you, that sounds superb!

[TRDK]

What is required to drive (… mW@32 Ω) the HEDD Audio HEDDphone TWO GT?

THX

Torben