Which HEDDphone®?

The HEDDphone® is the world's first headphone model to feature a full-range Air Motion Transformer driver, capable of reproducing a frequency range from 10 to 40 kHz. This feat of engineering, long thought out of reach, is the result of decades of experience in audio reproduction and a desire to bring the clarity and accuracy of our AMT driver, a proprietary design of an industry standard, to the headphone world.

Based on an open-back design, the HEDDphone® makes use of an updated geometry for its driver folds, a process we call Variable Velocity Transform (VVT), that allows the AMT to reproduce frequencies beyond its traditional use in monitors and be tuned for different uses. The result is a headphone that aims for a natural reproduction, letting the music shine rather than seeking to enhance or change it.

In this article we cover the evolution of the HEDDphone® since the release of the first model in 2019 with input from Dmitry Grigoriev, HEDD’s head of R&D and one of the key members of the team who helped develop and design this revolutionary headphone.

HEDDphone®

The first model, released in late 2019, proved the validity of our approach despite some ergonomic limitations. It was, and still is, much loved by audio professionals who found it to be a powerful studio tool for mixing and mastering. It won accolades and awards from Sound on Sound, Headfonia, VGP, Gearspace, and head-fi.org and became the go-to headphone for award-winning engineers who wanted to bring precision and clarity to their work, including Heba Kadry, Adrian Younge, Joker, and Tchad Blake, who collectively work across many genres and with some of the biggest artists and labels in the world. 

HEDDphone® Facts

The first headphone model in the world to use a full-range AMT driver capable of reproducing a frequency range from 10 to 40 kHz, thanks to an update to the geometry of the driver’s folds.

• Key specs: 718g; Mini XLR connection; soft ear pads made of vegan materials.
• Intended Users: audio professionals.
• Tuning: Neutral tuning from a studio monitor reference point of view, highlighting the midrange, source separation, and very wide stereo image. Typical feedback from listeners was that they "have a pair of speakers on their head."
• Accessories: one balanced cable and adapter.

HEDDphone® TWO

With the success of the first model, over the next three years we gathered feedback from our users and worked on refining various key aspects of the design.

With the AMT driver central to the concept of the HEDDphone®, the R&D team worked on improving the magnetic flux of the magnet-steel yoke-system of the driver. Dmitry Grigoriev explains how, “the thickness of the steel yoke and the size of the magnets were optimized for the most beneficial ratio of weight versus magnetic flux. The magnetic flux not only influences the sensitivity of the driver but also the punch and impact of the bass response.”

Next the geometry of driver’s diaphragm was also optimised to reduce modal resonances and increase precision in the reproduction of the audio signal. “The diaphragm underwent post-processing to improve distortion levels,” says Grigoriev. “AMTs are prone to high distortion levels as they are extremely undamped systems compared to typical voice coil or planar driver systems.”

"The reasoning for the HEDDphone® TWO was to create a studio reference reproduction of the source material on headphones, so you can take your studio with you." - Dmitry Grigoriev, Head of R&D

Central to the feedback we received were comments on the bulky design and ergonomics of the first model. This resulted in a couple of challenges for the R&D team: how to reduce the weight and how to improve the feeling of using the HEDDphone®?

Grigoriev says that “the approach was to attack the issue on every level, starting with the driver as described above. Then rethinking the headband system and creating a novel strap system that only has moving soft parts.” In addition, new materials like magnesium and carbon fibre were used to improve the build, resulting in an impressive 25% reduction in the overall weight of the model.

In rethinking the headband and tackling the bulkiness of the model, the team used a form follows function design approach so that every part of the HEDDphone® TWO contributes to offering a balanced audio image. “We also realised that the current headphone market does not offer anything in ergonomics adjustability when it comes to clamping pressure,” Grigoriev adds, “so we decided to develop the HEDDband system to offer this ability.”

HEDDphone® TWO Facts

Released in 2023, the HEDDphone® TWO features an improved AMT driver, reduced weight, and new accessories alongside the HEDDband system, an innovative approach to ergonomics which offers better comfort for extended listening sessions while also giving users more options for adjusting to their specific physical needs.

• Key specs: 550g; 3.5mm jack connection; faux-leather ear pads; 4-core high purity cable.
• Intended Users: audio professionals (primary), audiophiles (secondary).
• Tuning: Same neutral tuning as HEDDphone® with emphasis on the midrange, improved transient reproduction, realistic stereo image, tightness of the bass. The reasoning was to create a studio reference reproduction of the source material on headphones, so you can take your studio with you.
• Accessories: travel case, balanced and unbalanced cables and adapters, spare set of ear pads.

This new model was again well received by users and reviewers. Notably this time, while our goal was to offer a highly honest reference tool to help decision-making in mixing and mastering, both members of the professional and audiophile communities reacted positively to our design improvements, and in particular the way in which the HEDDband improved the ergonomics of the headphones. The original HEDDphone® was arguably less friendly to audiophile users, in no small part due to its weight, but the HEDDphone® TWO proved capable of bridging the divide between these two worlds.

HEDDphone® TWO GT

It was this positive reception and interest from the audiophile community that drove us to quickly iterate an update of the HEDDphone TWO.

The R&D team worked on a novel pre-processing of the AMT driver’s diaphragm that brings the distortion levels further down while keeping the system undamped. “The main difference however comes from the air compliance based tuning system,” explains Grigoriev. “This is achieved by selective enclosing of different air cavities with different air permeability properties allowing a precise ability to tune the AMT driver.”

The biggest challenge for the team however was how to balance HEDD’s mantra of offering the most natural reproduction of music with the understanding that a product intended for enjoyment first will need to be flexible enough to please a wide range of users who are looking for different things, unlike audio professionals.

"The GT is intended to go well with almost any source material, not a tool but rather a stimulant that allows you to fall back and enjoy your music." - Dmitry Grigoriev, Head of R&D

“As much as people have different preferences when it comes to music they like, they have different preferences when it comes to headphone tunings they like, this was the most exciting challenge,” says Grigoriev. The result is a tuning that “goes well with almost any source material, not a tool but rather a stimulant that allows you to fall back and enjoy your music.”

HEDDphone® TWO GT Facts

Released in late 2024, the first HEDDphone® model intended for listeners rather than professionals. Building on the success and innovation of the HEDDphone® TWO design, the GT features a new tuning, alongside additional visual touches and new premium cables and earpads options for a luxurious experience.

• Key specs: 550g; 3.5mm jack connection; lamb leather and velour ear pads; 4-core kevlar infused Oxygen Free Cable.
• Intended Users: Audiophiles.
• Tuning: An audiophile warm tuning that emphasizes the bass and treble, while taking the midrange slightly back to offer an increased depth perception and bass envelopment as well as intricate treble details and transients.
• Accessories: travel case, balanced and unbalanced cables and adapters, two sets of ear pads (leather and velour).

With the release of the HEDDphone® TWO GT we’re also introducing a new high-end cable upgrade for both TWO models. This high-purity Linear Crystal-Oxygen Free Cable offers lower impedance and increased detail retrieval that performs best with high quality amplifiers.

Whichever HEDDphone model you choose we hope it brings you closer to the music you love.