Berlin just picked another fight with the big boys. The new HEDDphone D1 is a German-made, dynamic open-back headphone built to challenge Sennheiser and Beyerdynamic on their own home turf. Using the world’s first Thin-Ply Carbon Diaphragm (TPCD) driver—developed with Sweden’s Composite Sound—the D1 fuses HEDD’s decades of acoustic expertise with cutting-edge materials science.
This isn’t boutique hype—it’s precision engineering turned into sound. Building on the success of the original HEDDphone and HEDDphone Two, the D1 aims squarely at the Head-Fi crowd chasing true reference performance. Expect clarity without bite, realism without fatigue, and just enough German attitude to remind you that “made in Berlin” still means something.
HEDD Audio: Berlin’s Father-and-Son Revolution in Sound
Founded in 2015, Heinz Electrodynamic Design (HEDD) is the brainchild of physicist Klaus Heinz and his son, Dr. Frederik Knop—a musicologist and mastering engineer who’s just as obsessed with sound as his old man. From their Berlin headquarters, they’ve built a reputation for designing loudspeakers and headphones that chase one thing above all else: absolute accuracy.
Klaus isn’t just another guy tinkering with tweeters. Before HEDD, he founded ADAM Audio, where he helped popularize the Air Motion Transformer (AMT)—a breakthrough that reshaped both hi-fi and studio monitoring. Not bad for a former physics student who once dissected speakers in the back of a Berlin shop during the 1970s.
Now teamed with Frederik—who swapped academia for audio—the duo has turned HEDD into a rare mix of old-school craftsmanship and modern engineering swagger. Their products, including the HEDDphone and HEDD Type 20 MK2 monitors, are made in Germany with the kind of precision that borders on stubbornness. Because in Berlin, “good enough” is what you call someone else’s product.
HEDDphone D1 Brings Thin-Ply Carbon Tech
The open-back circumaural design promises a spacious, natural presentation, while the lightweight chassis and dual textile-covered cables show some practical thought went into the design. You also get dual 3.5mm mono connectors, a 6.35mm adapter, a custom carry case, and a 5-year warranty—because Germans don’t build things they plan to replace next year.
At $799, the D1 doesn’t pretend to dethrone Sennheiser or Beyerdynamic overnight—but it’s definitely knocking on the door, clipboard in hand, asking some uncomfortable questions.
On paper, the HEDDphone D1 reads like a serious attempt to shake up the $500 to $750 category without pretending to reinvent physics. It’s an open-back, over-ear design, which means this isn’t something you’ll wear on the subway unless you enjoy sharing your playlist with strangers.
The driver is dynamic, not planar, but that’s where HEDD throws in its curveball—the Thin-Ply Carbon Diaphragm (TPCD). This ultra-light, rigid material is designed to move with precision and control, giving the D1 speed and articulation without the resonance issues that plague some dynamic models.
The frequency range—5 Hz to 40 kHz—leans into marketing territory more than necessity (your ears won’t hear much past 20 kHz), but it suggests plenty of extension at both ends. With a 32-ohm impedance, the D1 should play nicely with most desktop amps and even some higher-end portable DACs, though it’s clearly intended to scale with better gear.
A maximum SPL of 100 dB at 1 mW tells you it’s not chasing brute force but rather refinement and headroom. Comfort seems like a real consideration this time around: perforated velour pads for breathability, textile-covered premium cables, and a manageable 350 grams—a welcome break from the brick-like heft of earlier HEDD designs.
HEDDphone D1 Specifications
- Design: Open-back, over-ear headphone
- Drivers: Custom dynamic driver with Thin-Ply Carbon Diaphragm (TPCD)
- Frequency Range: 5 Hz – 40 kHz
- Maximum SPL: 100 dB at 1 mW
- Impedance: 32 Ohms
- Earpads: Perforated velour
- Cable: Textile-covered premium cable
- Inputs: Dual 3.5 mm mono connectors
- Weight: 350 g (net)
The Bottom Line
The HEDDphone D1 marks a new chapter for the Berlin-based brand—a $799 dynamic open-back headphone that blends serious engineering with real-world accessibility. Its Thin-Ply Carbon Diaphragm (TPCD) is the star of the show, delivering cleaner transients and tighter control without the damping compromises of traditional dynamic designs. Add a lightweight 350-gram build, premium cabling, and a 5-year warranty, and you’ve got a headphone that’s built for the long haul rather than another hype cycle.
At this price, the D1 steps directly into the ring with the Sennheiser HD 600 and HD 660S2, the Focal Clear, and Beyerdynamic’s DT 1990 Pro MKII—stiff competition from brands with decades of head start. But this is Berlin, not Bavaria, and HEDD’s mix of materials science and acoustic discipline makes the D1 more than just another German contender. It’s a challenge to the old guard, delivered with a smirk and a carbon diaphragm.
Where to buy:
Related Reading:
- The HEDDphone Two Is Lighter And Features An Updated AMT Driver
- HEDD HEDDphone Review: Meet The New Boss? Definitely Not The Same As The Old Boss
- Beyerdynamic DT 1770 Pro MKII Review: Refined And Affordable For Studio Work
- Beyerdynamic DT 1990 Pro MKII Open-Back Studio Headphones Review
