Headphone Reviews

Well, Sean Olive isn't going to like this review.

I was super excited for these to show up at my front door. In the midst of my RMAF show reports and trip to Boston for the Listen Inc. headphone measurement seminar, I found myself with a good stretch of time for just casually listening to the new Aeon Flow Open.

For me that means noodling around on Tidal for new music...music I'm not familiar with. I dig contemporary sounds from around the world so I decided to explore some African electronica. (Check out John Wizards, Zaki Ibrahim, Moonchild Sanelly, and Stab Virus.) The problem with musical journeying of this kind is you invariably stumble on numerous poor recordings. Somewhere along the line I found myself listening in a state of mild astonishment at how the Aeon Flow Open made everything sound good regardless of recording quality...within reason. But I'm getting ahead of myself.

Sound Quality
I find this headphone very hard to describe. Primarily it's because any time I use any adjective to give you a picture of the character of the sound quality you're impression will likely be too strong. The Aeon Flow Open is tuned with a very deft hand, and all its characteristics are remarkably subtle.

This is a mildly warm headphone; relaxed and inviting; both smooth and resolving. I'd say it's strongest characteristic is a very mild bloom in the upper bass and lower mid-range, and a slightly veiled or muffled character in the upper mid-range. If it sounds like I'm describing the HD600, you'd be right; this may be the closest I've heard.

In principle, I tend to think dynamic drivers have the upper hand in treble resolve over planars—both magnetic and electrostatic—which to my ears always have some sort of haze or blurring or zazz in the treble. I hear very little of that with the Aeon Flow Open; just a very slight zinginess 8-10kHz, which the included damping pads control very effectively. I'd also recommend wearing the Aeon Flow Open a little forward and low to reduce this effect. That said I do think it sounded ever so slightly rougher or grainier than the HD 600/650.

The Aeon Flow Open has significantly better bass extension and less distortion in the bass than the HD600/650—this is a significantly more weighty sounding headphone. I would like to hear a little more umph in the sub-bass, but that's rare to non-existant in an open headphone. MrSpeakers has done a great job of making an open headphone with an appropriately strong perceived bass response.

The Aeon Flow open comes with three sets of damping filters that very easily insert into the ear pad openings and which are held in place by a snug fit. The treble zing can be damped in ever increasing steps by: having no filter; inserting the black open-cell foam filter; the one notch white filter; or the two notch white filter. I don't hear these as effecting the treble amplitude response as much as I hear them imposing an ever stronger damping or deadening character. By the time you get to the two notch white filter it begins to sound like you're in an anechoic chamber...a little.

At first as I went through the filters I felt like the one notch white filter was for me, but as I listened over time I felt a little freer to use the filters both to modify the sound of the recording slightly, and, maybe to a greater extent, depending on my mood. Sometimes I wanted things smooth and mellow, and sometimes I wanted a little excitement. I found these filters very effective in adjusting the listening experience—more so than any other filering or tuning system in any other headphone I've experienced.

Imaging was very nice. While MrSpeakers calls this an open headphone, it has quite a bit more isolation than most other open headphones. So much so that I'm tempted to call it a semi-open headphone. In my experience, with open headphones that are almost transparent to outside sounds, you wind up not being able to develop a psychoacoustic differentiation of space between the musical space on the recording and the real acoustical space in the room around you. I think this gives you the impression of more depth to the music than is really there.

The Aeon Flow Open does provide a little isolation barrier between you and the acoustic space around you, which tends, to my ears, make the depth of image seem a little less than if it were a fully open headphone. None the less, the Aeon Flow Open delivers an image of very comfortable width and depth. Instrument separation and specificity are very good. The Aeon Flow Open strikes a wonderfully pleasing balance of precision and a sense of the whole in it's portrayal of space.

Likewise the dynamic punch is spot on. The Focal Elear, for example, has unbelievable punch; while I enjoy it, I find it at times a distraction form the musical experience. The Aeon Flow Open has plenty of punch when called for, but it's also not going to knock a tooth out. Again, a superbly balanced headphone.

One thing I noticed in measuring the Aeon Flow Open and confirmed in listening is that it's extremely sensitive to seal. If you don't have a good seal you're not going to get solid, punchy bass response. Those who wear glasses need to understand you'll not get the full experience with the Aeon Flow Open without removing your specs.

So why is Sean Olive not going to like this review? Well, the Aeon Flow Open really doesn't match up particularly well with the Harman target curve and yet I find it more pleasing than any other headphone I can think of, even when they match the Harman target better. MrSpeakers own Aeon Flow Closed is closer to the Harman target, yet I pretty easily prefer the Aeon Flow Open.

Even I can tell this headphone has a slightly more muffled or veiled sound than what I would consider technically neutral. And yet, over time the sound of the Aeon Flow Open tantalizes me with it's musical listening pleasure. I confirms my belief that getting close to neutral is important, but once close there's wiggle room to tune things around a bit to give the headphones a pleasing character. The Aeon Flow Open has taught me that while "transparent" is very good, "inviting" might be even better.

Summary
The Aeon Flow Open is a mildly warm and extraordinarily inviting headphone. Bass is powerful for an open headphone, but has a slight bloom in the upper-bass/lower-midrange. Midrange has a mild warm tilt and laid-back presence region. Very slightly muffled or veiled are both too strong a word, but it's there. Treble is articulate and without any harshness. There is a slight treble zing 8-10kHz, but is well controlled to taste with the included damping pads. Though not totally neutral, I find the Aeon Flow Open has an extremely alluring sonic character, and once my head had adapted to its sound I just didn't want to take them off.

Styling is a bit unusual, but quite appealing to my eyes. Comfort is second to none, though it's worth noting that the adjustment sliders do, from time to time, need to be tightened up to hold securely while donning and doffing the cans. Build quality is simply outstanding, with mostly metal and leather parts. Synthetic materials, when used, are top quality. Accessories are minimal having only a cable, 3.5mm to 1/4" plug adapter, and hard side, clam-shell case.

Hell yeah, the Aeon Flow Open is going up on the Wall of Fame. This is clearly, to my ears, the best sounding sub-$1000 open headphone on the market. Will it knock others off the wall? Hm. I think I've got to get the Focal Clear in here to do some comparing, but things will happen. In the mean time, get your head under a pair of MrSpeakers Aeon Flow Open headphones, this is a great headphone!

Video
View on YouTube here.

Resources
MrSpeakers home page and Aeon Flow Open product page.
SBAF thread and Hands post with CSDs showing effect of damper pads at 8kHz.
Head-fi.org impressions thread and review by MattTCG.