HEDDphone Two: moving waves like no other
by Diogo C
27th September 2023
Sponsored by HEDD
Founded in 2015 by physicist Klaus Heinz and his son, musicologist Dr. Frederik Knop, Heinz ElectroDynamic Designs - or simply HEDD - immediately caught the attention of the professional audio crowd, mostly due to two factors. Firstly, Klaus Heinz himself - he is a widely-recognized figure in the industry because of the company he founded in 1999, ADAM Audio. ADAM quickly became a key player in the studio monitoring game, as their products were highly rated by engineers and producers across the globe.
The second factor was the release of their first line of monitors, the “Type” series, which boasted a rich feature set, with onboard signal processing for speaker linearisation, balanced analog and digital AES connections, the option to use them as a ported or sealed speaker, and they featured the (at the time) new Air Motion Transformer tweeter, a driver concept that would eventually become a core feature of the entire HEDD line of products.
Based on an original idea from engineer and inventor Oskar Heil (1908-1994), the Air Motion Transformer (or AMT) is “unique in its way of making the air move” according to HEDD. Instead of the usual “piston-like diaphragms that move the air in a 1:1 ratio so that the diaphragm velocity equals the air velocity”, the AMT uses a folded elastic diaphragm that opens and closes to “breathe air in and out, with the special charm that the air driven through the folds is accelerated to a ratio four times as fast as the diaphragm itself”, thus resulting in a more accurate sound reproduction with an enhanced dynamic range. If you want to geek out on the inner workings of the AMT, you can do it here.
The HEDD Type 20 MK2 3-way Active Monitors featuring the AMT tweeter.
The Air Motion Transformer technology was first deployed in the tweeters of the X-ART model designed by Klaus Heinz during his tenure at ADAM and also on HEDD’s own Type series of studio monitors, but as we’ll talk about in a moment, HEDD would soon make the AMT driver full-spectrum - to cover the entire audible range.
The first HEDDphone
When HEDD announced that they were working on a new set of headphones, they had the pro audio community’s full attention. The first iteration of the HEDDphone (pictured right) was well-received and quickly gathered accolades. Its bold design and remarkable sonic characteristics were widely praised by professionals and audiophiles alike, and the eye-catching looks of the massive open-back ear cups made it distinguishable from other headphones.
The HEDDphone also marked a new high mark in transducer history, as the Air Motion Transformer driver was now used as a full-range speaker instead of being left to only high-frequency duties. HEDD pioneered another new technology in them as well: the Variable Velocity Transformation (or “VVT”), which allowed for linear reproduction of frequencies from 10 Hz all the way up to 40 kHz. This breakthrough was achieved by a complete overhaul of the driver’s geometry so that the folds on the AMT elastic diaphragm could vary in depth and width, thus dramatically extending its frequency range to cover the entire spectrum, from the deepest of subs to super highs.
However, even the most successful designs have room for improvement and although the first HEDDphone was very successful and garnered many positive reviews, it also received its fair share of criticism over its size and weight. It was time for HEDD to go back to the drawing board.
Enter phase TWO
Oftentimes a “mark II” is basically about giving a product a facelift, sometimes introducing minor changes or tweaks to certain components, and if we’re honest, it often feels like most “2.0” versions are closer to a “1.5” than anything. That’s not the case with the HEDDphone Two. This is actually a brand new product and the second entry in HEDD’s personal monitoring line, as the first HEDDphone will not be replaced by it, or discontinued.
No shortcuts were taken for the second version of the HEDDphone and a brand-new design was created from scratch, starting with the most crucial element: the transducer itself. The open-back design choice remains the same, but underneath it there’s an updated version of the Air Motion Transformer driver that was made especially for the HEDDphone Two, and this is an all-around improvement over the previous iteration: it’s more linear and precise in its frequency response from 10 Hz to 40 kHz, with better definition and dynamic range so we can hear every little sonic detail coming through the wires. This new updated AMT driver is also much lighter than the previous one, which takes us to another pivotal point here: comfort - which is ultimately tied to weight.
The first HEDDphone was widely considered to be a bit on the heavy side, and with a net weight of 730 grams that is hard to argue. HEDD managed to bring this figure down to 550 grams, which is roughly a 25% reduction - that is very meaningful in many ways, and to achieve that some serious redesign measures had to be taken both on the materials side and via mechanical aspects as well. This process culminated in “HEDDband”, the new carbon fiber frame that holds everything in place and provides the user with a high degree of comfort, even when listening over extended periods.
The HEDDband is super lightweight - the carbon fiber ensures that it is extremely durable and its elegant construction provides the perfect structure for the drivers so that they fit comfortably on the listener’s ears. On the top there's an ergonomic soft head pad that also adds to the overall comfort by reducing the top-down pressure, and on the sides the new smart strap system will provide only the desired level of campling, allowing users to adjust the height of the HEDDband to suit their head size and preferred tension.
The new HEDDband provides unmatched comfort.
The ear pads have also been redesigned with a new shape and a much smaller footprint, which helps reduce weight and bulk. The ear pads are made from highly durable leather with a soft cushion beneath it, and even those wearing glasses will be able to use their HEDDphones without applying unwanted pressure to the side of their head - eyeglass wearers amongst us will know exactly how frustrating it can be to use certain headphones! And since we are on the topic of leather, it’s important to highlight that the HEDDphones are made of vegan-friendly materials, with vegan leather in use on the band.
The cable connections have also been changed and they are now forward-facing instead of pointing down, which is a more natural orientation and adds to the ease of use since the cables won’t touch the users shoulders. The HEDDphone Two comes with two sets of cables, both measuring 2.2 meters but one comes with a 6.35mm termination and the other with a 4.4mm termination. Two adapters are also provided for converting 6.35mm to 3.5mm and for converting balanced 4.4mm to XLR. A carrying case and a spare set of earpads are also included in the package.
Lastly, the HEDDphone Two is relatively easy to drive with an impedance of mere 41 ohms, so they should be straightforward to use with most headphone amplifiers and those found on audio interfaces will probably perform fine with it, allowing users to enjoy their HEDDphones in virtually any situation. Nevertheless, using a great amp to pair it with is always good advice!
All HEDDphones are built by hand in Berlin, Germany.
Made for creators and listeners alike
The HEDDphone Two’s superb sound quality will certainly make professionals confident when mixing or mastering, and with the new added comfort it makes working long hours a lot easier. Synth legend Richard Devine, Korean producer Machìna, Grammy® award-winning producers Spike Stent (Coldplay, Lady Gaga), !llmind (Drake, Beyoncé) and Heba Kadry (Bjork, R. Sakamoto) have trusted their personal monitoring needs to the HEDDphone - a list that will grow larger with the TWO - but casual listeners looking for an enjoyable and super accurate set of headphones will also be at home here. The engineer, the artist and the audiophile will all be equally happy with the HEDDphone Two experience.
The HEDDphone Two will retail for €1,999 and is now available for pre-order. All HEDDphones are built by hand at HEDD’s facility in Berlin, Germany by a skilled workforce that takes great care at each stage of production. HEDD also provides a five year warranty for all their products, so it’s a safe investment any way you look at it.
For more information and to pre-order the HEDDphone Two, please visit: hedd.audio
Founded in 2015 by physicist Klaus Heinz and his son, musicologist Dr. Frederik Knop, Heinz ElectroDynamic Designs - or simply HEDD - immediately caught the attention of the professional audio crowd, mostly due to two factors. Firstly, Klaus Heinz himself - he is a widely-recognized figure in the industry because of the company he founded in 1999, ADAM Audio. ADAM quickly became a key player in the studio monitoring game, as their products were highly rated by engineers and producers across the globe.
The second factor was the release of their first line of monitors, the “Type” series, which boasted a rich feature set, with onboard signal processing for speaker linearisation, balanced analog and digital AES connections, the option to use them as a ported or sealed speaker, and they featured the (at the time) new Air Motion Transformer tweeter, a driver concept that would eventually become a core feature of the entire HEDD line of products.
Based on an original idea from engineer and inventor Oskar Heil (1908-1994), the Air Motion Transformer (or AMT) is “unique in its way of making the air move” according to HEDD. Instead of the usual “piston-like diaphragms that move the air in a 1:1 ratio so that the diaphragm velocity equals the air velocity”, the AMT uses a folded elastic diaphragm that opens and closes to “breathe air in and out, with the special charm that the air driven through the folds is accelerated to a ratio four times as fast as the diaphragm itself”, thus resulting in a more accurate sound reproduction with an enhanced dynamic range. If you want to geek out on the inner workings of the AMT, you can do it here.
The HEDD Type 20 MK2 3-way Active Monitors featuring the AMT tweeter.
The Air Motion Transformer technology was first deployed in the tweeters of the X-ART model designed by Klaus Heinz during his tenure at ADAM and also on HEDD’s own Type series of studio monitors, but as we’ll talk about in a moment, HEDD would soon make the AMT driver full-spectrum - to cover the entire audible range.
The first HEDDphone
The HEDDphone also marked a new high mark in transducer history, as the Air Motion Transformer driver was now used as a full-range speaker instead of being left to only high-frequency duties. HEDD pioneered another new technology in them as well: the Variable Velocity Transformation (or “VVT”), which allowed for linear reproduction of frequencies from 10 Hz all the way up to 40 kHz. This breakthrough was achieved by a complete overhaul of the driver’s geometry so that the folds on the AMT elastic diaphragm could vary in depth and width, thus dramatically extending its frequency range to cover the entire spectrum, from the deepest of subs to super highs.
However, even the most successful designs have room for improvement and although the first HEDDphone was very successful and garnered many positive reviews, it also received its fair share of criticism over its size and weight. It was time for HEDD to go back to the drawing board.
Enter phase TWO
Oftentimes a “mark II” is basically about giving a product a facelift, sometimes introducing minor changes or tweaks to certain components, and if we’re honest, it often feels like most “2.0” versions are closer to a “1.5” than anything. That’s not the case with the HEDDphone Two. This is actually a brand new product and the second entry in HEDD’s personal monitoring line, as the first HEDDphone will not be replaced by it, or discontinued.
No shortcuts were taken for the second version of the HEDDphone and a brand-new design was created from scratch, starting with the most crucial element: the transducer itself. The open-back design choice remains the same, but underneath it there’s an updated version of the Air Motion Transformer driver that was made especially for the HEDDphone Two, and this is an all-around improvement over the previous iteration: it’s more linear and precise in its frequency response from 10 Hz to 40 kHz, with better definition and dynamic range so we can hear every little sonic detail coming through the wires. This new updated AMT driver is also much lighter than the previous one, which takes us to another pivotal point here: comfort - which is ultimately tied to weight.
The first HEDDphone was widely considered to be a bit on the heavy side, and with a net weight of 730 grams that is hard to argue. HEDD managed to bring this figure down to 550 grams, which is roughly a 25% reduction - that is very meaningful in many ways, and to achieve that some serious redesign measures had to be taken both on the materials side and via mechanical aspects as well. This process culminated in “HEDDband”, the new carbon fiber frame that holds everything in place and provides the user with a high degree of comfort, even when listening over extended periods.
The HEDDband is super lightweight - the carbon fiber ensures that it is extremely durable and its elegant construction provides the perfect structure for the drivers so that they fit comfortably on the listener’s ears. On the top there's an ergonomic soft head pad that also adds to the overall comfort by reducing the top-down pressure, and on the sides the new smart strap system will provide only the desired level of campling, allowing users to adjust the height of the HEDDband to suit their head size and preferred tension.
The new HEDDband provides unmatched comfort.
The ear pads have also been redesigned with a new shape and a much smaller footprint, which helps reduce weight and bulk. The ear pads are made from highly durable leather with a soft cushion beneath it, and even those wearing glasses will be able to use their HEDDphones without applying unwanted pressure to the side of their head - eyeglass wearers amongst us will know exactly how frustrating it can be to use certain headphones! And since we are on the topic of leather, it’s important to highlight that the HEDDphones are made of vegan-friendly materials, with vegan leather in use on the band.
Lastly, the HEDDphone Two is relatively easy to drive with an impedance of mere 41 ohms, so they should be straightforward to use with most headphone amplifiers and those found on audio interfaces will probably perform fine with it, allowing users to enjoy their HEDDphones in virtually any situation. Nevertheless, using a great amp to pair it with is always good advice!
All HEDDphones are built by hand in Berlin, Germany.
Made for creators and listeners alike
The HEDDphone Two’s superb sound quality will certainly make professionals confident when mixing or mastering, and with the new added comfort it makes working long hours a lot easier. Synth legend Richard Devine, Korean producer Machìna, Grammy® award-winning producers Spike Stent (Coldplay, Lady Gaga), !llmind (Drake, Beyoncé) and Heba Kadry (Bjork, R. Sakamoto) have trusted their personal monitoring needs to the HEDDphone - a list that will grow larger with the TWO - but casual listeners looking for an enjoyable and super accurate set of headphones will also be at home here. The engineer, the artist and the audiophile will all be equally happy with the HEDDphone Two experience.
The HEDDphone Two will retail for €1,999 and is now available for pre-order. All HEDDphones are built by hand at HEDD’s facility in Berlin, Germany by a skilled workforce that takes great care at each stage of production. HEDD also provides a five year warranty for all their products, so it’s a safe investment any way you look at it.
For more information and to pre-order the HEDDphone Two, please visit: hedd.audio
