Overview

HEDD Audio (Heinz Electrodynamic Designs) is an audio manufacturer established in Berlin in 2015 by physicist Klaus Heinz and his son, musicologist Dr. Frederik Knop. Klaus Heinz is the son of physics Nobel Prize laureate Ernst Ruska and has the distinguished background of studying directly under Dr. Oskar Heil, the inventor of AMT technology. The company is committed to the continuous development of Air Motion Transformer technology, including the development of the world’s first full-range AMT headphone, the “HEDDphone.” They manufacture professional audio equipment ranging from studio monitors to headphones through handcrafted production in Berlin.

Scientific Validity

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HEDD Audio’s AMT technology demonstrates a certain effectiveness in measurement results. For example, the HEDDphone has the advantage of low THD (Total Harmonic Distortion) in the midrange. However, its frequency response has noticeable peaks, and applying equalization to correct this increases distortion in the high frequencies, meaning it does not achieve fully transparent sound reproduction. The studio monitor series also shows good performance, but it fails to establish a decisive advantage in measured performance compared to competing products at or below the same price point. While the potential of AMT technology is recognized, current products have several remaining issues.

Technology Level

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The company’s technology level can be evaluated as near industry-leading standards. A particularly high technical achievement is the realization of a full-range AMT headphone using Variable Velocity Transform (VVT) technology, which covers the entire frequency range (10Hz-40kHz) with a single AMT driver—a feat previously considered impossible. Founder Klaus Heinz’s experience in developing AMT technology for over 40 years underpins its originality and advancement. However, these advanced technologies do not always translate into measurement performance that overwhelmingly surpasses others, preventing a perfect score.

Cost-Performance

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HEDD Audio’s cost-performance must be rated as extremely low. For instance, compared to its flagship product, the HEDDphone TWO (approx. 270,000 JPY), the planar magnetic headphone Hifiman Ananda Nano, which offers equally excellent or superior measured performance, is available for about 80,000 JPY. Similarly, for its studio monitor, the TYPE 07 MK2 (approx. 160,000 JPY per unit), the Kali Audio LP-6 V2, which boasts similarly excellent measured performance, can be purchased for about 30,000 JPY per unit. The existence of alternatives that achieve equivalent performance at a significantly lower price, regardless of the technology used, means its performance-to-price ratio is remarkably poor.

Reliability & Support

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The reliability and support system exceeds the industry average. The company offers a long-term 5-year warranty upon product registration, which is a significant assurance for users. The handcrafted manufacturing at their Berlin factory suggests high-quality control. The long-standing technical achievements of founder Klaus Heinz also reinforce reliability. However, as a relatively new company founded in 2015, its long-term market reliability has yet to be fully established. Furthermore, the extent of its support network may not match that of major manufacturers.

Rationality of Design Philosophy

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The development stance of pursuing the potential of AMT technology is consistent and based on a scientific approach, which is commendable. However, the fact that its resulting products are extremely expensive for their performance calls the rationality of its design philosophy into question. The current reality is that products with equivalent or better measured performance are being realized at a much lower cost using other technologies. This suggests that the company’s chosen means—the adoption of AMT technology—does not necessarily lead to the most rational outcome in terms of sound quality and cost, thus lowering its evaluation.

Advice

HEDD Audio is a manufacturer for users with a strong preference for its unique AMT technology and for professionals who find value in Klaus Heinz’s technical legacy. However, when considering a purchase, it is essential to be fully aware of its extremely low cost-performance. For example, if you are considering the HEDDphone, there are planar magnetic headphones like the Hifiman Ananda Nano that offer equivalent or better performance for less than a third of the price. Similarly, for studio monitors, brands like Kali Audio offer products with comparable performance at a fraction of the cost. Unless you find a special appeal in the sound quality of AMT, we strongly recommend considering other more economical and rational options. It is crucial to conduct comparative listening tests with competing products and carefully judge whether the price difference is justified.

(2025.7.29)