FedEx finally decided to deliver my Drop+Dan Clark Audio Aeon Closed X (hereafter referred to as ACX) cans today, after driving them around the city for 12 hours yeterday. I am auditioning closed back cans to be my work headphones. I have also obtained a Schiit Fulla 4 DAC/Amp to run from my work PC with MusicBee serving as my music player. I have a collection of FLAC music files of various resolutions, with the majority being CD-quality.
ACCESSORIES
The ACX comes in a zippered hard carrying case with no handle, but a nylon mesh pouch on the inside for cables. Also included are 4 "tuning" pads that can be placed inside the cups to attenuate various aspects of the sound. One pair comes pre-inserted. I used that for my listening today. A single ended 3.5mm cable with a 6.3mm adapter is included. I purchased a balanced cable from Fog City Audio on Etsy to use with my DAP (Sony WM1A).
BUILD
The ACX is very light, being a mix of plastic and what feels like aluminum around the cups. It is not, however, cheap feeling. The metal wire headband has a memory, and can be bent any which way with no damage. This makes for a very good fit on a wide variety of heads. A leather head strap is suspended by two friction-fit sliders, allowing for up and down adjustment. The headphone is extraordinarily comfortable on the head.The pads are memory foam, about 3/4" thick and 1" deep. The foam inside the protein leather does move around a bit and requires a bit of massaging to straighten out.
SOURCES
Running through the Schiit Fulla 4 from my Surface Book 2 laptop, there was more than enough power to drive the ACX to my preferred 70dB listening level. The knob floats mostly around the 10 o'clock position to achieve this volume. Volume is uncomfortable (and dangerous) past 12 o'clock on the dial. On my DAP via balanced cable, volume was set around 70/120. Single-ended more like 82/120. So again, still plenty of headroom. On my less powerful NW-A45 Walkman, which only has 3.5mm output, volume was set at 85/120. My Xperia 1iii phone drove the ACX to the same volume via 3.5mm cable at 75% of the Android volume slider. I detected no difference in performance on any of these devices. Bass was just as deep, soundstage was the same, regardless of the power level of the given device. Given these experiences, I do not think the ACX requires any external amplification.
SOUND QUALITY
The sound profile of the ACX is (according to DMS) apparently very close to the Harman Target. This sounds right. Bass is pleasantly rich, but does not crowd out the middle or higher portions of the frequency. It's very balanced. The soundstage is relatively wide for a closed back and stereo image is good as well, with easily separated positions for instruments. Closed back isolation is quite good, making this an excellent choice for offices, coffee shops, and other moderate noise environments (probably not airplanes, though).
I have two points of comparison for "audiophile" headphones against he ACX - the Sony MDR-Z1R (my daily driver at home) and the Hifiman HE400SE, which I auditioned and rejected for the office due to its lack of isolation.
Against the HE400SE the ACX is significantly better. More bass, better isolation, equal detail and soundstage.
Against the MDR-Z1R I did some extensive comparison listening. The Z1R is Sony's TOTL headphone, with a 70mm dynamic driver and a special resonance attenuation chamber design. Here are my notes:
Emerson String Quartet - Beethoven String Quartet No. 7
Z1R much more involving on cello sounds, deeper bass reveals inner voice more. ACX delivers nice detail but not more.
Big Win for Z1R.
Herbert von Karajan/BPO - Beethoven Symphony No. 5 (1977)
ACX provides very detailed rendition, strings more forward. Good hall resonance, perhaps slightly better than Z1R. Less crowded sound than Z1R. Z1R emphasizes contrabass more, which adds good low end and balances things out nicely. Smoother, less crunchy sound.
Tie.
Counting Crows - Omaha
ACX Acoustic guitar stands out more, bass guitar gets a little muted. Percussion still nice and impactful. Z1R kick drum booms and churns. Acoustic guitar is enveloped in mix more.
Slight win for Z1R.
Coldplay - The Scientist
ACX a little thin on piano resonance, Chris Martin's voice lacks bass. Acoustic guitar is more convincing. Z1R portrays piano and its inner voice better, Chris Martin's voice more rounded. Deeper bass.
Slight win for Z1R.
Lady Gaga feat. Beyonce - Telephone
Gaga's vocal is richer on Z1R, as is the classical guitar intro. Stereo effects are also more pronounced. Bass churns. Oddly, ACX seems less in balance - when the dance bass line kicks in it seems way louder than vocals.
Win for Z1R.
Miles Davis - So What
Cymbals are a little hissy on ACX. Stand up bass is too recessed. Z1R sounds richer and more like a room, less like an old tape recording. Sax is richer on Z1R. Still a nice showing for ACX.
Slight win for Z1R.
Aerosmith - Janie's Got a Gun
Z1R renders bass and percussion better. ACX does a nice job on details.
Slight win for Z1R.
Nine Inch Nails - Head Like A Hole (remastered)
ACX tuning emphasizes hiss in recording. Trent Reznor vocal stands out nicely, and more than Z1R. Z1R smoother and more impactful overall, much less fatiguing listen.
Slight win for Z1R.
U2 - With or Without You
Z1R is smoother listen with deeper bass guitar rendition. ACX emphasizes the Edge's guitar part more and puts Bono more forward in the mix. Both engaging listens.
Slight win for ACX.
The Strokes - Selfless
Z1R smoother and darker, ACX a bit crispier and puts vocals slightly more forward. Both very engaging on bass guitar part and overall presentation.
Tie.
So all told, 7-2-1 Z1R/Tie/ACX.
I think this is a very good score for a headphone that costs 1/4 of its competition (granting the fact that the original non-Drop Aeon 2 Closed retailed for $800, or half of the Z1R). The ACX is terrific for rock and orchestral, and quite good for EDM and Pop. I like it a little bit less for Jazz and Chamber music - it's not bad by any means, but I think it's a bit too treble forward and bass light for those genres, at least compared to the Z1R. Of course if one had no basis for comparison, one would probably love it for those genres, too.
CONCLUSION
At their current price (keeping in mind they are sold out on Drop until March) they are a superb value, especially if you need a closed-back set of cans for travel or more challenging listening environments. They are easy to drive and come with a carrying case, making for a light commuting package for such high-quality listening. The sound profile is very "audiophile" in terms of detail and tuning, while still having enough bass to be fun for rock and EDM.
