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HEDD Audio HEDDphone TWO

Air Motion Transformer Headphones By Sam Inglis
Published November 2023

Three years ago, HEDD Audio developed the world’s first AMT‑based headphones — and before anyone else has had time to catch up, they’ve now replaced them with the second generation.

HEDD Audio HEDDphone TWOIt can be disconcerting when your favourite products are superseded by new versions. When even the manufacturer acknowledges there’s room for improvement, maybe the original wasn’t quite as great as you thought! Or, worse still, the Mk2 could turn out to be one of those paper upgrades that never quite sounds as good as the old one. Either way, you’re going to be left with a piece of kit that’s worth less than it was yesterday, and an awkward decision about whether to upgrade.

Among my own longstanding favourites are HEDD Audio’s unique HEDDphones. Sometimes called a ‘ribbon tweeter’, the Air Motion Transformer is used as a tweeter in several loudspeaker ranges, but HEDD are the only manufacturers who have managed to design a pair of headphones around it. The open‑backed HEDDphones are bulky, costly, heavy, and inefficient — but they sound absolutely glorious. To my ears, they combine the sonic strengths of planar magnetic and moving‑coil headphones, with deep and articulate bass, a very natural midrange, and a clear and open treble. Nevertheless, the HEDDphones are no more, and in their place we have the HEDDphone TWOs.


Since the launch of the HEDDphones, their designers have been beavering away to try to encapsulate the same sonic virtues in a smaller, lighter and more manageable package. With their huge oblong earcups, the original HEDDphones are the largest cans I’ve ever used, and whether or not you find them uncomfortable as a result — I don’t, at all — there’s no denying that they can make the wearer look a bit daft.

The earcup shape is retained in the HEDDphone TWOs, but the dimensions are noticeably smaller. They’re still big headphones that stick out several inches, but it feels less like strapping a pair of NS10s to your head. And with the reduction in size comes a reduction in mass: at 550g, the new version is around 25 percent lighter. If you’ve tried typical models from manufacturers like Audeze and Hifiman, these won’t seem like outliers.

’Til The Band Comes In

There’s also been a revolution in how you strap these earcups to your head. The first‑generation HEDDphones used a pretty conventional headband, with the only adjustment on offer being the ability to make this longer or shorter as required. The HEDDphone TWO employs an entirely new, patent‑pending design called the HEDDband, which has multiple modes of adjustment, allowing not only the height but also the width and the pressure of the headband to be set by the user.

The HEDDband permits an unusual degree of flexibility of adjustment.The HEDDband permits an unusual degree of flexibility of adjustment.This is easier to understand by watching the video on HEDD Audio’s website than from a written description, but in essence, the outer, structural headband contains within it a floating, padded ‘roof’ that sits on top of your head. Straps emerge from either end and from the top of this ‘roof’ piece, pass through holes in the outer frame and are held in place by small pegs on the outside. By making these straps longer and shorter, it’s possible to control how far the ‘roof’ sits below the structural headband, and also how forcefully the earcups are pulled inwards.

It’s an ingenious system, and effective too, but you need to take the HEDDphones off in order to adjust the straps, so it can take a few attempts to find the optimal setting for any given head. Since the straps are secured using holes spaced nearly a centimetre apart, it seems at first as though the range of adjustment will be too coarse, but in practice, that’s not the case at all, and even if you adjust both sides at the same time, a difference of one hole either side is quite subtle. I had no difficulty achieving a setting that felt comfortable to me — but, having been perfectly happy with the comfort of the original HEDDphones, I didn’t notice a radical improvement in the TWOs.

Something that is a major improvement, however, is the provision of a high‑quality, lightweight, semi‑rigid case with a carrying handle. When you’re spending this much money on a pair of headphones, you want to be able to keep them safe when not in use! HEDD Audio are clearly confident that they are built to last, too, because they’re offering a five‑year guarantee.

Like the originals, the HEDDphone TWOs use three‑way connectors at the earcups to cater for balanced signals from headphone amps that can supply them. This time around, however, the cables attach using TRS mini‑jacks rather than mini‑XLRs. Two cables are supplied: a conventional unbalanced one terminating in a quarter‑inch jack, and a balanced one with a four‑pin XLR at the other end. These have their own little nest within the case.

The Air Motion Transformer generates sound from a diaphragm which is folded like the bellows of a concertina.The Air Motion Transformer generates sound from a diaphragm which is folded like the bellows of a concertina.

Next Level

Having succeeded in making the HEDDphones smaller, lighter and more ergonomic, have HEDD Audio also managed to maintain their sound quality? The answer, in the best possible way, is no — because they haven’t merely matched the sound quality of the original HEDDphones. They’ve bettered it.

With an impedance of 41Ω and a sensitivity of 89dB/W, the specifications are similar to those of the originals, but HEDD say they have significantly improved the performance of the Air Motion Transformer in the TWOs, and this is borne out in their subjective quality. It’s not a night and day difference, or one that’s equally apparent on all material; they still sound like HEDDphones. But, side by side, I consistently preferred the new version — which is impressive, considering how much I like the originals!

If I had to sum up what I love about the HEDDphones it’s that, paradoxically, they are the least headphone‑like headphones I know of.

If I had to sum up what I love about the HEDDphones it’s that, paradoxically, they are the least headphone‑like headphones I know of. Working with them feels more like working on a high‑quality speaker‑based monitoring system than is the case with almost any other cans. The HEDDphone TWOs simply take this even further, as though you’re working on an even better pair of monitor speakers in an even flatter room. The originals still present a marvellously clear and balanced sound, but the TWOs are somehow even smoother through the sibilance range. At the bass end, meanwhile, low‑frequency extension is impressive on both, but there’s an additional richness to the TWOs that somehow connects the bass to the low midrange more naturally, without ever sounding overblown or exaggerated. And, of course, all the existing strengths of the HEDDphones are retained.

When I reviewed the originals, back in 2020 (, I said that hearing music on them is a bit like being in a good mastering environment. They’re extremely revealing, but not in a brutal way. If you’ve overcooked the low end, overlooked sibilance or pushed the midrange too hard, they’ll administer the most polite of taps on the shoulder to let you know! And if the mixes are good, listening to music on them is pure heaven. Many times during the review period I put on test material to audition some specific aspect of their performance, and half an hour later found myself buried in a favourite album.

In their new incarnation, the HEDDphone TWOs are still relatively bulky, still quite heavy, and still require a good headphone amp. And, sadly, they still aren’t cheap. But they remain very much one of my favourite products — and if you’re considering a pair of high‑end headphones for producing, mixing or just getting lost in music, they need to be on your shortlist.


HEDD Audio’s innovative AMT‑based headphones have got smaller, lighter, more portable and more adjustable — and they sound even better!


€1999 including VAT.