I’m here today with a review of the Aeon Closed RT, purchased back in 2021 for $500 as my first experience with DCA headphones. I eventually used it for a 15% Club DCA discount on the $4k Expanse and $900 Noire, so I’ve certainly gotten my money’s worth from the Closed RT.
No photos this time since I sold these to a friend before taking them.
Build and Accessories
For the price, the Aeon Closed RT is definitely one of the best built headphones out there – while it’s not especially premium (being mostly plastic-adjacent build), everything is solid, well fitted, and free of any odd creaks or squeaks. The Hirose connectors are my favorites, being secure, extremely durable, and easy to use. They do make replacement cables more expensive, but many custom cable shops seem to carry them now.
On the accessory front, the Aeon RT comes with a carrying case, cable, warranty card, 4 tuning filters, and the pre-attached ear pads. Nothing incredible, but good for the price. The carrying case is a nice and large hard shell, since the RT doesn’t fold like DCA’s higher end headphones, but this extra space makes for a nice area to store the cable and some other odds and ends. It’s certainly very protective, and a nice little value add.
The stock cable isn’t the best, and worth replacing fairly quickly. It’s heavy and a little stiff, but worst of all is that it’s very microphonic. With the price of Hirose connectors, a replacement cable hurts the value proposition of the Aeon RT quite a bit but is a necessary expense in my opinion.
Finally, the headphones come with 4 pairs of tuning pads, ranging in how much dampening they do. The thinnest black foam might as well not exist for how little it changes the sound. I’d say that at least it protects the drivers from dust and debris, but there’s already a thin fabric filter. Can’t hurt, I guess. On the other end, the white pad with 2 notches will significantly reduce the treble and effectively bring up the mids and bass.
It's nice that DCA provides these as options, effectively giving 5 different tuning options (even if the black foams aren’t much different from not using any filters). For this review, I used mostly the two white pads (1 notch and 2 notches) as well as no filter.
Comfort
Just as important is comfort, where the Aeon Closed RT really shines. The earpads are large enough for even my Dumbo ears, although the tips of my ears do touch the drivers and edges of the pads. This personally didn‘t bother me, and there were no sharp edges, but this is obviously very subjective.
They extend quite far – you’d have to have a pretty large head before that becomes a concern here. The earcup pressure is snug, but not skull crushing. One small complaint here is that they can be slightly uncomfortable if you wear glasses, depending on the width and placement of the legs.
Bass
The bass on the Closed RT is best described as ‘lean’ in kind terms, or ‘anemic’ in less kind terms. There’s really no way around the fact that, without any of the filters, the Closed RT has a frequency response shaped like / a slash. While there is bass, you’d have to turn up the volume to get much sensation of rumble, thump, or impact. And at that point the treble becomes piercing and fatiguing. And while the bass takes to EQ well, you’d need a pretty significant bump to bring the bass and subbass up to a ‘normal’ level. While things like iFi’s XBass II will bring up the low end, it ends up being very V-shaped instead of normal sounding.
Mids
Mid recessed, hollow and thin due to little bass. This applies to all kinds of vocal, both female and male, high and low. Lower voices tend to lack real rumble and it often ends up coming across as grit instead. With thicker pads, the mids become natural and filled out, but this comes with sacrifices to the treble and treble detail (not necessarily badly).
Treble
There’s an icy edge to higher vocals – the imbalance between mids and treble is so severe that it sounds like the higher portion of a voice within a single sound is over-emphasized while the lower portion is recessed. Miwa doesn’t sound hoarse, but instead oddly thin and piercing at times with a slight grain to her voice. Inhales and other breath sounds are almost sharp at times, as if they singer was gasping for breath. There’s also slight sibilance on s sounds and cymbal hits.
Adding the thickest (white with two notches) filter brings down the piercing sensation and makes voices more cohesive, but the treble is still fatiguing and slightly grainy. The filter also brings down the attack on leading edges, leading to a more smoothed over and generally less detailed sound. This isn’t necessarily a bad thing – the sound becomes much easier to listen to and goes nicely with the comfort and isolation to make for an all-day pair of headphones.
Conclusion
Overall, you can definitely tell that the Aeon Closed RT is the cheap little sibling of the bunch. It’s got the weirdest tuning, weakest detail retrieval, and least compact build. However, this doesn’t mean that the Aeon Closed RT is a bad headphone, especially for a closed back at this price.