The ATH-A900X is a closed headphone Audio-Technica developped some time ago, part of the “ART” family of A-T headphones, serie of closed circum models while the “AIR” serie was the open-back line.
The ATH-A10, in 1994, was the first ART model, and since then, many, many iterations have been released.
Build quality is decent, and comfort a mixed bag ; I sometimes have issues getting a good seal since the A900X cups do not swivel in a Y-axis.
○ Release : 2011
○ Current status : Discontinued
○ Type : Over-ear / Closed-back
○ Measured weight : 341g
○ Impedance : 42 Ohms
○ Sensitivity : ~102.7 dB/mW
○ Average used price : $100-150
The ATH-A900X is a colored sounding headphone, substantially on the warmer side of neutral. It’s a relaxing and easy listen.
Mid-bass to lower-mids is quite strong, adding an enveloping amount of warmth and body to the sound and notes – I don’t mind it for particular listenings, but not for a polyvalent use. Sub-bass is soft between 40-60hz, and almost inexistent below that frequency.
Midrange is lower-mids emphazised, but remains quite present and not too withdrawn up to 2 khz. There is a major dip in the lower-treble area (4-7khz), where lot of resonances and harshness might happen. This dip, combined with the lower-mids warmth, is what makes the A900X sound smooth and relaxing. Mid and upper-treble are a bit lacking, though a minor peak at 10khz is apparent on some tracks.
This headphone sounds quite wide for a fully closed design, beating most closed headphones I have heard, and a lot of open-back models (Sennheiser HD600, for example). But the A900X lacks the transparency and openness, and isn’t a technically remarkable headphone, with just decent attack and transient response. Most “3d-wings” AT I have heard did not have great overall technicalities, like the Audio-Technica ATH-W1000X or ATH-AD900X.
Notwithstanding, I like the A900X for desktop use and relaxing sessions, when I am not looking for pure “audiophile” listening where I would reach for a more capable and balanced pair of headphones. This Audio-Technica has a decent build quality, with good comfort (when I can get a seal) and enough isolation for a lot of situations. At maximum $150 for a pair in mint condition, I believe they’re a good option.
Measurements & Resources
Bass roll-off below 40-50 hz, bump around 100-300 hz, recessed upper-mids above 2 khz, relaxed treble. This measurement exhibits a channel imbalance, pretty common with the A900X. My pair also had minor channel imbalance.