Selected Comparisons
The following comparisons to the HEDD Audio HEDDphone TWO GT were completed using the Ferrum WANDLA GSE DAC paired with the OOR/HYPSOS amp and PSU.
HEDD Audio HEDDphone TWO
The HEDDphone TWO was launched late in 2023, with our review coming out in early 2024. It is not a discontinued model but rather tuned and designed to appeal to a different target audience.
Technical
I have gone into significant detail regarding the technical differences between these two headphones, so I will keep it light here.
At a high level, both are open-back headphones with AMT drivers using a Klapton diaphragm.
The key difference here is the new multi-layered Kapton polyimide film combined with the external acoustic dampening materials to not only produce a new tuning but also a much quieter physical driver, i.e., no crinkle noise.
Both headphones are rated at 41Ω with a 1dB difference in SPL (mW) at 88 dB for the HEDDphone TWO GT and 89 dB/mW for the non-GT driver.
I found the GT version required more volume than the regular ‘TWO’ version, but both need decent amps to sound optimal; the more Vrms headroom, the better they will sound.
Design
I hope this is not purely anecdotal, but suppressing the HEDDphone TWO GT driver crinkle, combined with what seems to be a firmer frame,e has created a much quieter design than the non-GT model. That is a huge plus in my book.
The form factor and weight are unchanged, as is the unique HEDDband strap system. You should, with practice, get a nice pressure balance to suit your head size.
The new velour pads provide an important element within the HEDDband adjustment structure, mitigating a little more lateral pressure than the leather pads on my head.
The loss of the white labeling with a more understated etched pivot block and generally a darker theme is a step forward.
I like understated, which is why I like the general look of the new finish, but I am less keen on the garish white stitching on the HEDDphone TWO GT leather strap at the top of the carbon fiber headband arch.
The cable choices are unchanged, but the finishing has been upgraded with a new looser braided fabric jacket and gripper barrels. It makes a difference. They feel lighter and easier to manage, and the barrels are much better for grip.
Performance
I wouldn’t define the HEDDphone TWO GT as sounding warmer. A better description would be that it is more dynamic, and the HEDDphone TWO is more rounded-sounding.
Much of that has to do with how the low-end and upper-mids/lower treble are shaped. The HEDDphone TWO GT has more elevation around 100Hz, ensuring its mid-bass punch is more dynamic and fuller sounding.
From 20Hz up to 200Hz, the bass amplitude of the HEDDphone TWO GT FR has increased, so the corresponding fundamental frequency has also increased, making it a more appropriate performer for more bass-oriented modern synthwave, pop, and R’n’B.
However, the HEDDphone TWO has a more elevated lower-mids, so what it lacks in power, it compensates with a fuller sound from instruments through this range.
The TWO GT is sub-neutral in this region, so the improved power doesn’t translate into heavy warmth and thicker note presence through the mids.
Despite having more ear gain from around 1k-6k, the note weight is slightly leaner with more contrast than the rounder, richer TWO GT midrange.
Those differences also draw from the treble tuning. There is more of it from the GT, especially as we move into the upper treble around 8- 10k, which, harmonically, is picked up by a stronger 3- 4k presence.
That adds more contrast and reduces the decay a little more for me, giving a more precise and slightly cleaner sound for higher-pitching vocals and instruments.
The separation is there, perhaps even more so than the older TWO. The HEDDphone TWO GT sounds taller and deeper, with more midrange separation and a staging quality I would define as less intimate.
The HEDDphone TWO can sound more intimate and is more suited to those who want their vocals front and center with a more even harmonic coloration.
HEDD Audio HEDDphone
The original HEDDphone was launched in 2020, with our review being published in the same year. You can still buy this headphone directly from HEDD Audio at a reduced price of €1699.
Technical
On a high level, the HEDD Audio HEDDphone TWO GT driver retains the same basic principle as the first-generation version. Inside both circumaural open-back headphones is a full-range Air Motion Transformer driver, or AMT.
The 1st gen AMT driver pre-dates both of the newer versions, so whilst it has a folded Kapton diaphragm, the polyimide film is not multi-layered and lacks the same acoustical treatment as the HEDDphone TWO GT version.
That means it is more exposed to pressure and has a higher level of audible driver crinkle when applying pressure on the cups or moving them around. It also sounds very different, an aspect I explain in more detail in the performance section below.
The ratings are not hugely different, however. The HEDDphone TWO GT is 1Ω lighter at 41Ω for impedance and has a sensitivity level of 88 dB/mW, which is only 1 dB more sensitive than the original’s 87 dB/mW benchmark.
There is a very small difference in sensitivity in favor of the new HEDDphone TWO GT on paper, but testing from the balanced output of the Ferrum OOR, I found the original HEDDphone to be a tiny bit more sensitive and able to run at a lower volume.
Design
I have a hot take on the comfort differences between these two. The HEDDphone TWO GT is clearly lighter and, for many, the more comfortable headphone with superior adjustment via its unique HEDDband system.
However, there is something to be said about HEDDphone’s looser clamping pressure and bigger pads. I find them comfortable; that’s the hot take. Feel free to disagree.
Perhaps it’s the larger inner cavity on the pads, but my ears generally enjoy the additional space afforded to them from the original HEDDphone.
What is not controversial is the weight. The HEDDphone is super heavy, perhaps one of the heaviest headphones I have ever tested at 718g.
If you are not raised on a diet of older 600 g+ planar headphones, the gen 1 HEDDphone will seem uncomfortable with tons of vertical pressure from that old-school single headband system.
Aesthetically, the HEDDphone TWO GT looks more like a HEDD audio product than the original HEDDphone. The older design is a classic headphone system with massive cups, whereas the GT has more of an in-house identity, similar to how they finish their speaker systems.
The final significant change is the switch from larger mini-XLR connectors to slimline 3.5mm TRS angled ports molded into the base of the HEDDphone TWO GT cups. It’s a factor in the lighter weight of the GT headphones, for sure.
Performance
The HEDDphone TWO GT is the HEDDphone perfected. Those who are still fans of the original’s tuning will find a safer harbor by bypassing the HEDDphone TWO and going straight to the GT.
It has the original’s deeper staging quality, but this time with more mid-bass punch and impact, so it sounds more extended and powerful with a better fundamental frequency than the original.
If you are going for a driven ‘faster’ sound, the GT will provide more snap and dynamics, and for reasons explained below, it also sounds a little cleaner and more precise in delivering it.
The HEDDphone TWO GT retains some of that ethereal quality in the highs that the original did quite well in conveying. However, you will notice the GT has more treble fill and presence, given that the HEDDphone has less midrange and lower treble amplitude, especially around 5k-8k.
One thing to note with the original’s tuning is that it has a little more lower-mids amplitude than the HEDDphone TWO GT’s FR, specifically around 500Hz-1k, which can result in a more intimate, warmer sound for vocals and instruments pitching in that region.
However, the GT’s instrumental separation and vocal presence are much better. The sense of space and air through the mids is more palatable, whereas the HEDDphone feels a little more subdued in the same region.
My Verdict
The HEDD Audio HEDDphone TWO GT adds a new, wider, and more appealing dimension to their headphone sound signatures. Whilst the non-GT still has an edge for its beautiful, rich vocal sound, there is no denying that the GT version brings a more pleasing level of power and punch to the line-up.
This tuning immediately appeals to casual and discerning modern music lovers with its improved depth and headroom. And might I add, the driver build is physically so much quieter than the non-GT sample I currently own.
If that observation is not anecdotal, then credit to the HEDD Audio team for building a much smoother wearing experience.
Aside from that, everything else is pretty much steady as she goes, and overall, that is a good thing. A new lick of paint on an already unique headphone frame, combined with the flexible HEDDband system that should fit just about any head.
HEDD Audio HEDDphone TWO GT Specifications
- Concept: Open-back over-ear
- Driver: Full-range Air Motion Transformer (AMT)
- Diaphragm: Multi-layered Kapton polyimide film
- Frequency range: 10 Hz – 40 kHz
- Sensitivity: 88 dB/mW
- Impedance: 41 Ω
- Weight: 550g
- Power Requirements: 200mW (minimum), 1000mW+ (recommended)
- Cables: High-purity and silver-plated copper with nylon braids
- Ear Pads: Velour and sheep leather
