The ADX5K packs a huge 58mm dynamic driver, a tungsten-coated diaphragm utilizing what Audio-Technica are calling “Core Mount Technology”. The driver, baffle, and voice coil are all mounted in one integrated unit without any moving parts. This was done to reduce unwanted resonance and create high rigidity for a better transient response. Translation: the driver is designed to resolve forward and rearward movement more quickly and accurately, meaning it can deliver fast detail and decay notes in as realistic a fashion as possible. And I will take Audio-Technica at their word for it, as it is a wholly accurate-sounding implementation.
Driver sensitivity is rated at 100dB/mW, and nominal impedance at 420 ohms, relatively high amidst a slew of low-impedance planar competitors. Fans of tube amplification – particularly of the output transformer-less (OTL) variety – will take delight in this fact. The ADX5K’s high impedance means they are a fine pairing for the relatively high output impedance of some tube amps.
So how do they sound? The short version: bright, nuanced, and intimate.
Pop the ADX5K’s onto your head, plug them into an appropriate source of good amplification (and good music!), and you’re immediately met with one of the most starkly detailed, transparent and airy tunings of any headphone I’ve ever tested. The ADX5K’s are a bright pair of headphones – there’s no point mixing words. The treble is definitely the star of the show here, but unlike other headphones that “fake” detail by pumping up everything above the 7kHz+ department, the ADX5K resolves treble detail with more aplomb that anything I’ve tested. I’m generally not treble-sensitive and do tend to prefer a more forward/brighter presentation. However, some headphones I’ve found simply too ‘much’ in the treble department – for example the original HiFiman HE-5, which I found to be a sibilant, hot mess; and the HiFiman HE6-SE, which I found nasal and uneven in the upper registers. While the ADX5K does fly close to the sun in that department, it balances those gobs of detail with linear performance right through-out the frequency response, for an incredibly rewarding and revealing listening experience.
Aiding the ADX5K’s sense of detail is its surprising speed. Those big 58mm tungsten-coated drivers are able to dispatch fast, snappy and complex passages with lightning agility, contributing to an overall tonal characteristic that leans towards dry, and metallic.
Bass-heads need not apply – there’s no mid-bass hump to add ‘warmth’ or the perception of bass extension, it simply isn’t there. What the ADX5K does have, however, is incredibly impressive bass texture. The ADX5K won’t thump-out deep-reaching, electronic bass in the way that a planar – say, for example, like the Audeze LCD-X might – but the ADX5K has the best presentation of stringed bass (bass guitar & double-bass), I can recall. Paul’s electric bass in ‘Golden Slumbers’ from Abbey Road (check the 50th anniversary remaster if you haven’t yet!), is taut, impactful and felt as well as heard. The double bass introduction from ‘California One / Youth and Beauty Brigade’ from The Decemberists ‘Castaways and Cutouts’ feels sounds like it’s being performed right in front of you, with the texture and resonance from the bow coming through with uncanny realism. The fast bass passages in ‘Peg’ by Steely Dan (especially around the 1:06 mark) are a real treat.
I’d be lying if I said the ADX5K were a master-of-all-genres, they ain’t. Their lean, airy presentation lends themselves best to acoustic, live, and stringed music; and intimate music at that. Unlike the ‘vast’ sound stage of the HD800/HD800s, the overall scape of sound painted by the AD5X is far more intimate and immediate. Rather than a ‘concert-hall’ presentation, it’s more of a small club. But, what a club it is you get membership to with the ADX5K. Distinct instruments, voices, and sounds can be located and plucked-out from inside a 360-degree field with laser-like accuracy. The combination of the left/right guitar tracks, soaring synth (with amazing decay), and snap + hit of the snare/tambourine combo in ‘Arizona’ by Kings of Leon makes for a simply awesome immersive, 3D experience (and a great tune too).
Rock music can be a bit hit-or-miss with the ADX5K. Take a well-produced track, like the Butch Vig-produced ‘In Bloom’, and you’re treated to a tight, brutal and enjoyable rock classic. But try listening to looser recordings, like some the heavily distorted (the bad kind, not the good kind of distortion) mixes from Baroness, and it’s a sizzling, fatiguing ordeal. A shame really, as their music is kick-arse.
Mids are where the music lives, and so does the human voice. And while voices don’t feel hugely ‘forward’ thanks to a dip around the 2kHz mark, combined with additional energy in the presence (~7kHz) and air (~12K) departments on the AD5K, they are presented with excellent texture and realism. The ADX5K slightly prefers the higher register of female voices, and a great example is ‘Soothing’ by Laura Marling, which it delivers with incredible realism and nuance. In fact, that track is all-round one of the best-suited tracks for the ADX5K that I can think of.
VS ZMF EIKON
The ZMF is another expensive dynamic headphone, but it takes a very different approach to both craftsmanship and playback. For starters, it’s a wooden close-back design with a bio-cellulose driver, and they are much heavier due to their ‘heirloom’-type construction. Although, I must say the Eikon does carry its portly form pretty well when worn. The ADX5K immediately displays far less bass impact and extension, particularly in the sub-bass region. The ADX5K does give a good account of itself representing the bouncing bass passages in ‘I am a Very Rude Person’ by Thom Yorke, whereas the bass booms with more visceral weight on the Eikon, although it is a little flabbier. Vocals are a little ‘boxy’ on the Eikon compared to the ADX5K – on ‘You and I’ by Chicago alt-rockers Wilco, Jeff Tweedy’s vocals sound ‘cupped’ by comparison on the Eikon, like he has his hands wrapped around his mouth. The AD5X, on the other hand, has a much ‘drier’ presentation mid-range and vocal presentation.
The comparisons continue on Page Three, CLICK HERE, or use the jump below