VS MRSPEAKERS AEON FLOW OPEN
The Aeon Flow Open from MrSpeakers is almost like the spiritual opposite of the AD5K. In some ways, it’s a terrific complement if you were looking to change things up depending on your mood, or style of music. The Aeons are very much a ‘lean-back’ style headphone, with a warm, smooth tilt and a warm mid-bass hump. The ADX5K, on the other hand, isn’t a ‘relaxing’ listen at all. They grab the music by the ears and extract every last trickle of detail and force-feed it to you without filtering. Take the classic AC/DC track ‘Whole Lotta Rosie’, for example. The ADX5K shoves more snap and snarl from Angus Young’s lead guitar into the mix, with huge amounts of energy and attack. The Aeons, on the other hand, transmit more of a ‘wall of sound’. It’s not at all unpleasant, but it’s far less aggressive, and it’s difficult to pull-apart the separate instrument track – Angus’ lead guitar track in the right channel nearly gets buried into the mix. The speed in which the ADX5K deals with transients is apparent in ‘Reverse Running’ by one-album supergroup Atoms for Peace (a great test-track for fast transients and bass quality). The staccato snap of the left-right-panned percussion is dealt-out with lightning-quick speed on the AD5X’s, by comparison making the MrSpeakers planars feeling almost ponderous, although this is probably emphasized by the (relatively) withdrawn mids on the AD5X which do make it feel less intimate and congested.
VS GRADO GH1
This was a somewhat surprising head-to-head. The first release from the Grado Labs ‘Heritage Series’ range – the maple-bodied GH1 – put-up a closer tonal and detail-retrieval match than anything else I had on-hand to compare the ADX5K directly to. The GH1 carries a fairly typical mid / treble-forward Grado signature and was nearly able to keep-up with the ADX5K in several aspects – mainly transparency, speed and tone + texture in the upper mid-range. But ultimately the Audio-Technicas pulled-ahead with superior resolution, linearity and overall refinement. Sticking with the Atoms for Peace record for a moment, the track ‘Stuck Together Pieces’ shows both cans to present similar levels of energy and bite, but the Audio-Technica nudges-ahead of the Brooklyn-born GH1’s for instrument separation and imaging. Khruangbin’s ‘Maria También’, from the excellent album ‘Con Todo El Mundo’ reveals the greater bass impact of the ADX5K, and the speed of the guitar and drums make for a more dynamic listen on the Audio-Technicas.
VS SENNHEISER HD600
This is probably a very unfair comparison, but the Sennheiser HD600 is rightly a legend in this hobby and remains a benchmark for many in terms of a neutral, natural presentation. A side-by-side comparison of the two headphones on ‘Know Your Enemy’, from Rage Against the Machine’s superbly-produced debut album (rightly a ‘benchmark’ in its own right) quickly shows the technical superiority of the Audio-Technica’s in nearly every regard. Powering them simultaneously out of the 2 x single-ended outputs on my Questyle CMA600i, it’s interesting to note that they take just about the same amount of power to reach similar sound-pressure levels. There’s immediately more dynamics, bass impact, and detail top-to-bottom on the ADX5K. The Audio-Technica’s mids feel relatively ‘scooped’ compared to the HD600s, adding to the sense of a greater sound stage, with clearly more apparent separation and more focused imaging. However, the HD600s do sound like they’ll be definitely less fatiguing and severe over long listening periods – they have a famously relaxed, neutral approach.
VS SENNHEISER HD800s
Disclaimer – I don’t have a pair of HD800s in the house at the moment to directly compare with, so please take these thoughts with a grain of salt. The ADX5K definitely has a far more intimate presentation in terms of soundstage compared to the truly wide Sennheisers. The HD800s is a ruthlessly revealing pair of headphones, but I think I give the edge to the ADX5K when it comes to ultimate transparency and air. Bass extension feels about on par (from memory), but the ADX5K feels like it has more overall weight and body top-to-bottom. Other things being equal, the build and design approach of the Audio-Technicas nudges them ahead in my books, along with their more intimate and insightful sonic character.
AMPLIFICATION AND PAIRING
During my review time with the ADX5K I powered it with a mix of both solid-state and tube flavour, including:
- Questyle Audio CMA600i
- Crack + Speedball upgrade from Bottlehead audio (with Sylvania 6SN7 input tube & Tung-Sol 5998 power tube)
- Hagerman Audio Labs ‘Tuba’ (with Mullard EL34 tubes) – review inbound too, by the way!
- Chord Mojo
Despite their relatively high impedance, the ADX5K didn’t prove onerously hard to drive. They do demand a quality desktop unit however. Mobile devices (and definitely smartphones) might run out of puff before powering the AD5X to proper listening levels. The ADX5K proved to be one of the toughest asks I’ve made of Chord’s Mojo, requiring the little mobile DAC/amp to get into the ‘double green’ volume area to get to satisfying volume levels. Bass impact on the Mojo did sound a little lean when quickly switched-over to the CMA600i, which is my go-to class-A reference solid state desktop amp. The Questyle happily powered the ADX5K at 9 o’clock on its motorized volume pot, and offered a typically neutral, powerful and dynamic pairing with the ADX5K.
Moving over to the pair of tube amps previously mentioned – the Crack + Hagerman ‘Tuba’, and things got a little more interesting. One of the benefits of high-impedance dynamics are their ability to pair with higher output-impedance sources, meaning you can make use of their comparatively different characteristics, as well as that of different tubes. If you want to go down that path. And, if you hate money (I digress). The Bottlehead amp offers an immediately more ‘polite’ upper octave, and slightly more bloom in the bass department. This is particularly interesting if you’re concerned about potential fatigue from the lean, analytic voicing of the AD5K, and also if you want to simply change things up from time to time. The ‘Tuba’ from Hawaiian manufacturer Hagerman Audio Labs has a lower output impedance (in the “HI” output) than the Crack – 32 ohms, versus ~90-120 ohms (depending on the output tube used), but proved to be a slightly different kettle of fish compared to the Crack. The Tuba easily powered the Audio-Technicas with plenty of headroom, but interestingly gave away nothing in terms of treble resolution compared to my solid state amp, and also tended to bring-out a richer and slightly less analytical character from the ADX5K’s, more noticeable over longer listening periods. The Tuba was a happy medium for me with the ADX5K, compared to the more euphonic presentation on the Crack, and the leaner style of the CMA600i (which is, in all likelihood the closest representation to the ‘truth’).
I’m not going to get into DAC pairings, but I will note that I especially enjoyed vinyl playback with the ADX5K via both tube amps mentioned above. A well-mastered recording + a well-maintained record and turntable system is an absolute joy with the right pair of cans, and the Audio-Technicas were superb to listen to LP after LP from my Rega Planar 2 and Shure M91ED cartridge. Perhaps the analogue chain took a bite out of the ADX5K’s ’reference’-style analytic approach, calming them down a notch? Or, perhaps I just enjoyed the ceremony of pairing a wonderfully-crafted pair of cans with albums that I’ve gone to the trouble of acquiring and playing-back via shiny tubes? Again, I digress.
So having spent a good fortnight or so living with the ADX-5000, how do I feel about sending them back? Well, I’ll genuinely miss them, to tell the truth – they’re unique. Objectively, they’re not for everyone, and there’s a lot of things they don’t do as well as other flagships. The HD800s have them handily beaten for sound stage, and, truth be told, for value. At $1,499 (at time of writing), with an included bonus balanced cable, it’s an easy decision if you’re splitting hairs – after all, they are more similar sonically than they are different. Most kilobuck planar options from Audeze (such as the LCD-X and LCD-3) best the Audio-Technicas for bass extension; and many other options in this price bracket (both dynamic and planar) offer a more romantic, easy to live with ‘musical’ tuning by comparison. What most impressed me about the ADX-5000 is the fact that they’re quite singular – they have a minimalist approach to design and comfort and have been engineered to deliver insight and detail into your music above all else. The ADX-500’s are a niche proposition, and an expensive one at that. But if I’ll remember one feature of the ADX-5000, it’ll be the sense of air. And in terms of where these Audio-Technicas are perched in the flagship headphone realm, they do occupy rarefied air indeed.