Today, we will discuss the new HEDDphone D1, the world’s first Thin-Ply Carbon Diaphragm over-ear open-back headphone! We will discuss their build quality, design, and sound quality, paired with several headphone amplifiers and DACs, including the Ferrum Audio ORR, WANDLA, HYPSOS 2 stack, the Ferrum ERCO, the Chord Hugo 2, and the Woo Audio WA22 and McIntosh MHA200 headphone tube amplifiers.

I will also make some brief sound comparisons to another open-back headphone as a reference in a similar price range for sound quality towards the end of the video, so stay tuned for that!

About 8 years ago, HEDD Audio imagined bringing Thin-Ply Carbon into a headphone design. After extensive development and refinement in collaboration with advanced diaphragm designers at Composite Sound of Sweden, the HEDDphone D1 was born!

This is a significant milestone for HEDD Audio for a few reasons. It is their first dynamic driver headphone, and secondly, it is the first time we are experiencing HEDD Audio’s sound signature at this price, of $799.

This puts the headphone in direct competition with many fabulous headphones for audiophiles, music lovers, and even music producers who work in the audio world every day.

Let’s discuss the TPCD driver technology a bit more. Made from Thin-ply Carbon, which, according to HEDD Audio, outperforms conventional carbon fiber, has superior stiffness, low mass, and durability.

According to HEDD Audio, TPCD eliminates the need for traditional diaphragm damping, enabling faster, cleaner, and more accurate performance.

With a 32 Ohm impedance and 100 dB sensitivity, the HEDDphone D1 will be far more compatible for listening than HEDD Audio’s other headphone offerings, which require headphone amplification to perform. 

That is not to say that the D1 won’t perform better sonically and scale with a dedicated headphone amplifier or your favorite tube amplifier; it just means that, depending on your listening preferences, the headphones are efficient enough to perform without a dedicated headphone amplifier.

Each HEDDphone D1 is handmade in Germany and is fully serviceable, with an industry-leading 5-year warranty when registered with HEDD Audio. 

Let’s discuss the D1’s build quality and comfort. The headphones should fit any head size with ample headband adjustment. The headphones are also very lightweight, weighing only 350g —the lightest in the HEDD Audio family.

The earpads are very plush-feeling, made from perforated velour, and feel excellent when worn. The depth and the width of the cups are also great for my medium-sized ears, preventing my ears from ever touching the drivers.  

The ear cups also feature a swivel mechanism for an excellent fit. The cups use dual 3.5mm mono connectors for those of you who own premium headphone cables already terminated in 3.5mm. The included cable is of decent quality and is terminated with a 3.5mm plug, and also includes a 1/4” adapter for headphone amps.

The D1 feels well-built, with a mix of hard plastic and metal components, all of which are serviceable and replaceable. The headband is fantastic, with ample padding and a shape that makes the headphones an absolute pleasure to wear.

I like the subtle HEDD logo; if you look carefully behind the metal on the cups, it's a nice touch. I also appreciate the headphones' darker color, which is not overly flashy but tasteful. HEDD Audio has also included a nice carrying case for the headphones. 

So let’s talk about how the HEDDphone D1 sounds! The Open-back design of the D1 delivers a natural sound that is a pleasure to listen to for long listening sessions without fatigue. 

The soundstage is very well separated and relatively spacious, especially at this price. The soundstage does a great job of delivering the production level on a given track, presenting more intimacy on a recording designed to sound intimate, or a larger scale if it was recorded and produced that way.

Reaching from 5Hz to 40 kHz, the D1 has impactful, deep bass and airy, well-extended treble without ever sounding muddy or bright. The D1 delivers about 4dB more sub-bass than the ever-popular Sennheiser HD-650, while following its signature fairly closely up until around 100Hz-200Hz, where it pulls back a bit, delivering a cleaner sound in that region. The D1 has much better air and extension in the treble.

In the 1k-2k range, compared to the HD-650 and HD-660S2, the D1 places a bit less emphasis there, making vocals sound a bit smoother in delivery with a touch less clarity than the very midrange-focused Sennheiser headphones. 

String instruments sound very natural and well-defined, and their timbre across the entire frequency range is natural and lifelike. Cymbals stand out well on “Once Upon a Time in the West” by Dire Straits, and the electric guitar has a hypnotic quality to its sound.

I think HEDD Audio has done a terrific job of producing a set of headphones with tonal qualities similar to Sennheiser’s HD650 and 660S2, but with better soundstage separation, deeper bass, and better treble extension. These are not analytical headphones, nor are they dark headphones.

I love the D1’s signature and categorize them as neutral warm, with exceptional detail, transparency, and resolution for a dynamic driver headphone in this price range, with a very gratifying low end.

Listening to Jeff Beck’s Who Else album and the track Brush with the Blues shows off the body and soul of the D1 headphones, with an intoxicating quality to the electric guitar and bass, and excellent balance with the percussion instruments.

Listening to Led Zeppelin’s Kashmir (Live: O2 Arena, London) from the Celebration Day album is excellent and makes you feel like you're at the concert!

Listening to Queen’s We Will Rock You (Remastered 2011) and the D1 headphones sounds so natural, engaging, and emotionally moving. HEDD Audio has created a spectacular headphone that puts the entire headphone industry on notice, in my opinion, besting more expensive models.

I am a big fan of the HD650 and 660S2, which I use as references in many of the videos we create on this channel. The HEDDphone D1 is a better-sounding take on German-made dynamic headphones, priced higher, but, in my opinion, it is the exact upgrade from the HD650 and 660S2 that many listeners are looking for without spending a significant amount more. 

Listening to Thievery Corporation’s Fight to Survive and the D1 excel with this genre of hip hop style vocals and electronic rasta inspired beats. The deep, satisfying bass, the airy top end, and the excellent vocal presence are fabulous.

Listening to Cave from Yosi Horikawa on the Vapor album is mesmerizing and showcases the soundstage separation, detail reproduction, and low-end prowess the D1 is capable of. 

Listening to Desire from Bob Moses and ZHU, and I can’t get over how much I enjoy these headphones, and I rarely say this, but I feel like these headphones are going to set a new standard for headphones under $1000 and make other manufacturers re-access what their headphones offer if they are more expensive than $799.

Listening to one of my favorite contemporary electric jazz albums, Jason introduced me to many years ago —Snarky Puppy’s We Like It Here — is superb. The D1 sounds full, while still sounding airy, and tonally so delicious and accurate. 

The soundstage placement and definition of each instrument are spectacular, and the brass never sounds harsh or too bright, with the headphones providing impact and speed to some of the more complex passages on this album.

Listening to A Perfect Circle’s The Noose, gives me a physical reaction, releasing oxytocin and making my skin tingle. Maynard’s Vocals lead you into this amazing song in a soothing way, with such a superb tone. When Billy’s guitar and Josh’s percussion come in at 1:52, I get chills again. The headphones have a way of enveloping you in their sound with just the right amount of warmth without sounding too warm, balanced by the excellent mid-range and top end.

Listening to Judith from A Perfect Circle, and all I want to do now is clear my schedule and listen to Tool, A Perfect Circle, and Puscifer for the next several hours, which is precisely what I did!

 I believe Freddie and HEDD Audio have created a set of headphones that will appeal to listeners across all genres, as well as for music producers and musicians, shaking up the headphone industry at this price with their extremely comfortable fit, reasonable clamp force, superb headband, light weight, and, most importantly, spectacular class-leading sound quality. BRAVO, Freddie! I need a pair of these headphones for my collection!

The new HEDDphone D1 is available for purchase on our website, and purchase links can be found in the video description or by visiting us directly at thesourceav.com or at our 10,000 sq ft Showroom and headphone bar in SoCal, so that you can listen to the headphones yourself alongside many others.

Also, TSAV has added some great options on our website. Our rewards program lets you earn points redeemable for discount coupons on future purchases. We have also expanded our financing options. So, check those out and sign up for the rewards program today!

We have some exciting videos coming this year, featuring new product announcements, so please consider subscribing to our channel! From $100 earphones to multi-million-dollar home audio, cinema, and automation, TSAV is a HiFi paradise for building the system of your dreams.

This is the part of the article where we would love for you to share your thoughts on the new HEDDphone D1 in the comments. Let us know what you think! Until next time, friends, remember, let the music be your guide!