The looks of an alien-phone?
Intro
Earlier, I reviewed the Aeon Open X and found it a bit underwhelming. Now, I’ve had the opportunity to evaluate its closed-back counterpart. Is it any better? There’s a common belief in this hobby that closed-back headphones are more challenging to tune correctly compared to open-backs.
This review will be shorter than usual given it’s more of a comparison.
Specs & Comfort
Retail Price: US$ 499
Transducer size: 62*34 mm (advertised)
Transducer type: planar magnetic
Earpad size: 120*80*33-25mm
Earpad fitting mechanism: glued-on
Sensitivity: 91 dB/mw @1kHz
Impedance: 14Ω @1kHz (measured), flat
Connector: dual 4-pin locking DUMMER type
Weight: 342 grams
Clamping force: medium-low
Headband swivel: Y (approx. 60°)
Comfort: 8.5/10 (very good)
Caveats (build quality etc.): NA
Mesurement & Sound
link to the frequency response measurement & more comparisons
Tonal balance:
Overall, it’s a clean and balanced sound, though perhaps a bit bland in the mids and highs. Most instruments are rendered realistically, but vocals can be somewhat sibilant and intense at times.
The bass is tight and thumpy, striking a nice balance between quality and quantity. There’s adequate slam and punch – not the most thunderous, but with good body and impact. The extra lift is clean and tight, avoiding any bleed into the mids, which would otherwise cause muddiness. I much prefer the bass on these over the open Aeon X. Compared to the Moondrop Para, the Aeon Closed X offers more bass quantity, although the bass structure is more ‘linear’ on the Para.
The midrange sounds quite neutral as a whole, but it leans slightly towards the lean and somewhat gritty side. ‘Uncoloured’ may not be the right word here, since the timbre is not the most natural. Perhaps ‘bland/faded’ would be an apt description. Notice the dip between 200Hz and 1500Hz in the frequency response; this contributes to the effect of less warmth and body in the mids. Apart from that, it’s fairly neutral. They remind me of the midrange timbre on the Moondrop Para. With well-recorded tracks, the mids feel lively and realistic. However, with certain female vocalists, they can be a bit shouty and sibilant, as discussed below.
The treble is bright yet somewhat intense, erring on the splashy side. Sibilance tones can be rather pronounced, even in songs not mastered to be particularly vocal-forward/bright. Consequently, many female vocals, such as Lana Del Rey’s “Ride” from Born to Die, can sound quite shrill. Male vocals are generally fine, as they typically don’t reach these high frequencies. Instruments, however, benefit from this tuning, sounding crisp and sharp.
Note that this is without any damping foam. But even with one insert, it remains quite bright and sibilant. It improves with two inserts, though it’s still somewhat peaky in the upper treble between 10-12kHz, which is apparent on instruments like the crash cymbal (or songs like Patricia Barber’s “The Wind Song”). This is reminiscent of Hifiman planars like the Ananda or the Arya. In comparison, the Open X offers a marginally smoother response in the high frequencies.
Other qualities:
- Soundstage and Imaging:
The soundstage is mediocre – which could be a compliment given this is a closed-back headphone. Despite the closed design, it doesn’t feel claustrophobic, which is a pleasant surprise. The mids are somewhat forward, but the horizontal stage doesn’t feel narrow or cramped. It’s not as wide and diffused as the Para, though. Stage depth is quite good, but the bass can be a bit indistinct and takes up considerable ‘room’. Elements in the mix are clear, with a sense of distance between them.
- Clarity:
The clarity is impressive for the price, though perhaps a bit overly articulate. With poorly recorded music, it can sound gritty and edgy. However, with well-mastered tracks, it’s typically very enjoyable, offering a clear sense of resolution and layering. The sense of texture and detail in the mids are commendable in particular. It is a much better performer in this regard than the Open X, the latter which suffers from considerable bloat in the upper-bass and lower-mids. It straddles somewhere between the Hifiman Sundara and the Moondrop Para in terms of overall level of clarity.
- Dynamics and Impact:
The dynamic qualities are decent, surpassing the Open version. However, there’s still some degrees of compression: the contrast between soft and loud elements tends to be a bit ‘mushy’, though better than the Open X. The attack and decay are much cleaner than the Open X, which may have contributed to a better sense of dynamics.
The sense of impact is very good, enhanced by the closed-back design. Leakage significantly reduces impact, though, with almost no bass immediately the seal is broken. But with a good seal, it feels adequate. Compared to the Audeze MM100, the Aeon Closed X offers more bass quantity and thump but doesn’t feel as linear.
With additional damping inserts, the dynamic qualities are somewhat dulled, although I still find it superior to the Open X overall.
Conclusion and value:
Priced at US $499, the Aeon Closed X stands as a commendable mid-fi planar. It offers a fairly neutral sound profile. When considering sound quality alone, its price point may seem slightly steep. My main complaint is the highs, which can sound rather sharp for most genres. If you’re comfortable with open-backs, there are better options for sound quality alone. To me the Moondrop Para, the Hifiman Edition XS offer better value for money.
Nevertheless, it seems to me the Aeon Closed X does carve out an ‘ecological niche’ for itself. Its closed-back design offers a bass boost seldom found in open-back planars, adding an element of excitement and fun. Additionally, they provide effective isolation from external noise. If these align with your priorities, the Aeon Closed X merits consideration. Keep an eye on Drop.com, as they go on sale quite often, making it a more attractive deal.
Pros: crisp and clear sound; tight and punchy bass; excellent midrange clarity and articulation; sparkly highs; ergonomics.
Cons: the treble can be intense without damping inserts; inserts dull dynamics; somewhat compressed sounding; tough competition at its price point.
Value Grade (assessment on value, NOT sound quality):
Notes on EQ
The DCA Closed X benefits quite a bit from EQ. I find a cut in the upper treble zing area between 10-13kHz essential for restoring natural timbre. The rest is more or less optional by comparison.
My EQ setting for this headphone:
Preamp: -6.0 dB
Filter 1: ON PK Fc 25 Hz Gain 6.0 dB Q 0.700
Filter 2: ON PK Fc 100 Hz Gain -2.0 dB Q 1.000
Filter 3: ON PK Fc 180 Hz Gain 2.6 dB Q 3.000
Filter 4: ON PK Fc 230 Hz Gain 1.5 dB Q 1.000
Filter 5: ON PK Fc 1000 Hz Gain 0.8 dB Q 3.000
Filter 6: ON PK Fc 2200 Hz Gain 3.5 dB Q 2.500
Filter 7: ON PK Fc 3300 Hz Gain -2.5 dB Q 3.000
Filter 8: ON PK Fc 5800 Hz Gain -1.5 dB Q 3.000
Filter 9: ON PK Fc 10600 Hz Gain -3.0 dB Q 3.000
Filter 10: ON PK Fc 12800 Hz Gain -2.5 dB Q 3.000
If you would like to EQ to the Harman Target, there’s an handy AutoEQ function built in Squiglink that you could use as a starting point (I personally do not recommend doing so – ideally you should adjust the filters to suit your own hearing especially in the treble).
MEASUREMENTS
Frequency Response Average (unsmoothed):
Bass extension cutoff is 10hz instead of 20hz on the extende frequency response measurement, so as to fully capture frequencies which though may not outside of the ‘audible range’, may be felt by our ears, bones and muscles and enhance the sense of ‘impact’. The response is obtained by an average of positional variations. The graph is unsmoothed to better show the peaks and dips that might be audible.
Positional Variation:
This graph shows how the tonality might be affected when you wear the headphones differently on the head.
Leakage Test:
This graph demonstrates how a small leakage (simulated using thin-armed glasses) can result in FR change.
Impulse Response:
Impulse response contains information about transducer movement when a test tone is played.
Channel Matching:
Channel matching graphs DOES NOT RELATE TO SOUND PROFILE.
a specialised configuration is used to capture channel differences to mitigate the interference from positioning on rig and the asymmetricity in GRAS pinnae design (legacy of KEMAR).
the Left (blue) and Right (red) channels are measured on a flat plate coupler with an IEC60318-4 ear simulator.
Electric Phase & Impedance:
The above graph shows the measured impedance (green) and electric phase (grey).
END OF THE ARTICLE
Disclaimer: This review is not sponsored or endorsed by any business or related entity. The headphones reviewed are my own unless stated otherwise. Any links or recommendations included are purely informational and do not involve any financial affiliation or endorsement on my part.
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