Superlative extension and resolving power, Endgame imaging, Well-balanced yet non-fatiguing tuning, Outstanding soundstage depth
Mostly large and heavy design, Note presentation can sound unorthodox relative to competitors
The HEDDphone offers summit-fi performance at high-end pricing, I applaud HEDD for perfectly balancing long-term listenability and huge resolving power in their modern masterpiece.
When it comes to premium products, story often precedes performance and Heinz Electrodynamic Designs (HEDD) has such a wonderful inception. Founder and CTO Klaus Heinz is more than a successful entrepreneur, he’s a physicist who designed and built the first commercial units of Oskar Heil’s Air Motion Transformer under ADAM Audio – where it has been a staple in their high-end studio monitors to the current day.
We’ve seen this technology pop up in other speakers such as the Kanto TUK and many of oBravo’s ultra-premium designs. By freeing up his focus from expanding ADAM’s line-up, Klaus was able to further his innovations at HEDD with his son Dr. Knop, where the team was inspired to build the HEDDphone. There’s been a lot of noise surrounding this model recently, not only due to its pricing, but also since it represents a world first in two regards – the first headphone sporting an AMT driver, and the first full-range AMT driver design. In fact, the full-range nature of the driver here has netted it another name, the variable velocity transformer (VVT) representing an evolutionary step in geometry over the tweeters built before. The HEDDphone is a true statement product, yet also a piece of innovation at a price point that remains attainable to a wide range of enthusiasts.
The HEDDphone is available for $1899 USD. You can read more about the HEDDphone and its technologies and treat yourself to a set on HEDD’s website here.
I would like to thank Klaus from HEDD very much for his quick communication and for providing me with the HEDDphone for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.
- Page 1: Intro, BTD, Unboxing
- Page 2: Design, Build & Fit
- Page 3: Sound & Source Pairings
- Page 4: Comparisons & Verdict
Behind the Design –
Klaus has extensive experience with Oskar Heil’s (1908-1994) air motion transformer designs under his previous company Adam Audio. This driver type was adopted and is desirable due to the velocity of the sound output. Traditional speaker designs, including DD, Estat and Planar drivers operate like a piston and therefore, move sound at the same velocity as the diaphragm itself. AMT drivers differ in that they employ pleated mylar folds that permit the driver to accelerate sound output up to four times higher in an accordian-like fashion. This is significant since it results in a higher efficiency driver, substantially faster transient response and higher fine detail retrieval and resolution. When considering the full-range implementation utilised within the HEDDphone itself, the AMT driver also poses benefits for bass response due to its space-efficient pleated design that means the effective surface area of the driver is up to five times higher than what may otherwise be permitted in a headphone design. You can read more about the AMT driver and its benefits here and here.
The AMT to VVT Evolution
AMT drivers are conventionally able to extend down to 650Hz and are, therefore, mostly implemented for their ability to provide accurate high frequency reproduction as tweeters. Headphone design presents different challenges than studio montitors, but also some desirable traits such as a more efficient seal aiding bass reproduction. HEDD have approached this by altering the geometry of the AMT driver folds. Rather than sporting consistent width, the VVT driver features larger and deeper ripples for the low-end and smaller for highs. In so doing, the VVT driver is able to reproduce a full-range frequency response, alow greater flexibility over the desired sound signature and still uphold the desirable characteristics of a traditional AMT driver. Though the HEDDphone is not truly the first headphone using AMT technology, it is the first to solely use an AMT driver (others such as oBravo’s HAMT range being hybrids).
Like many at this price, the HEDDphone comes in an enormous hard box that reinforces its premium status. Within is a card information page providing insight into AMT technology and usage instructions. The HEDDphone itself is snugged within a laser cut foam inlet with the cable in a separate hard box below. No other accessories are included such as a pouch or case, nor balanced cable. Still, perhaps especially at this price point, many headphones do not include these accessories as they are not intended for portable use – though I would say it would be a reasonable expectation for them to include a balanced cable. HEDD sell their OEM balanced cable at an additional $189 USD. It should also be noted that though the HEDDphone uses mini-XLR connectors, the wiring pattern is reversed so cables for other headphones will have inverted phase. This should not be audible to the vast majority though the OEM HEDD cables are most recommended for this headphone as a result.