Got the Aeon 2 open and I am very happy with it so far!
These are the most natural sounding planars I have personally heard, they sound very similar to a HD650 with new earpads (new earpads part being important as the 650s treble rolls off some when the pads wear down!).
All the other planars I have heard have a kind of artificial edge to them, almost like turning up the sharpness filter a lot on a tv, very very clear but sort of unnatural. The Aeons somehow keep the clarity but make it sound more natural, really impressive.
I am not sure that I could have appreciated these without having tried a lot of other headphones though, as the way they impress is subtle. I didnt have my mind blown as soon as I put them on, I was just surprised as how "correct" everything sounded. After trying them for a bit I also got shocked by how much detail these produce, its really off the charts. Every tiny hiss,pop, chair squeak, etc is reproduced in a way you can hear clearly, but without being really irritating. I didnt realize there even was little hisses and pops in some of my recordings. These are definitely very capable of being a reference headphone.
FR is for the most part very good, there is some extra energy (2-3db) around 200hz which can make things a tad too warm sounding, but its not much a issue at all and I guess most people will like the effect. The midrange is perfect imo, very smooth and flat response giving mids a very natural sound, though a little warm with male vocals from the 200hz energy at times.
The bass is pretty well extended but drops off a lot after 24hz to my ears, even EQing it up this region is a little weak, bassheads will be disappointed. Not surprising as these are relatively small single sided planars, they arent going to be able to shatter your teeth the way some of the giant Audeze double sided drivers can. For me its the perfect kind of bass response as its gives a solid amount of impact and punch but it is not headache inducing. I like my bass but I am quite sensitive to it being too overblown in the subbass, it actually gives me a headache. So for me I am very happy with it.
Shockingly the region from 1-3k doesnt have the dip that 95% of planars on the markets have, its actually the proper level! Dan deserves a ton of praise for these feat alone, as I find most planars to sound very off without EQ because of that ubiquitous dip, but here its actually very well done. There is actually a little too much energy around 2.6k but again its like 1-2db over, very small thing and much preferable to the dreaded planar dip. Personally I dont mind it! This means guitars actually sound alive! The 3-5k region is a little relaxed compared to something like the Hd650. I think it could use a bit more energy around 4.5k especially to make it sound a little more lively, some may find it a touch boring because of this but its not too much of a issue.
The lower treble is probably the area that some will find bothersome as there is a lot of energy from about 5.4k to 6.1k, for my taste about 2-3 db or so too much. If you are really sensitive to this region, you will likely want to apply some EQ or use the tuning pads which I think address this region, but many people will likely like the effect this has and wont be bothered by it. The other potential treble issue is the region f rom about 7.1-7.8k which also has a lot of energy, for my tastes again its about 2-3db too much (a trend!). The amazing news is that this does not make the Aeon sibilant at all unlike many other headphones I have tried. The rest of the treble is spot on for my taste and extends very well and very clearly, easily goes up to 17.3k which is the limit of my hearing and does so at a near perfect level to my ears (sounds close to same volume as midrange, not too dipped or overblown).
Sibilance is just not a issue with the Aeon which is super impressive considering it actually has a fairly energetic treble response,most headphones with this kind of sound profile would be real sibilant. It either eliminates the sibilance entirely or changes it from a stab to the ear to a gentle poke, enough to let you know its there but not be bothersome.
The Aeon 2s soundstage is very interesting and quite unusual. Its again very much akin to the Hd650 style of soundstage, which is to say its not super wide, but its very accurate. However it can at times go considerably wider than the 650 and the imaging is much better. I say its unsuaul because with most songs it sounded like the 650 style of soundstage but when I tried Letters by Yosi Horikawa I was really suprised by how far out the pen writing across your head went. It sounded like it was well outside of the earcup. It also performed the feat of making it sound like the pen was going all the way from outside your head through your head and out the other ear that many headphones fail to do. I think it matches the HE5se for imaging which was the best I have heard previously.
Personally I prefer this kind of soundstage rather than the superwide style that some others go for, as I find they sound diffuse to me. Some may have a issue with this though if they are looking for that.
I have been comparing them with my VERY heavily EQed Koss ESP 95/x (13 bands of parametric EQ
) and the Aeon 2 is better even without any EQ at all. Didnt expect it to be able to beat an electrostat in detail but.. it does and it does so while sounding a lot more natural than the Koss does. The Koss does sound taller, larger and airer than the Aeon which is not surprising because its drivers are huge and its VERY open. The Aeon is actually closer to a semi-open or semi-closed headphone than a open one IMO, the isolation is surprisingly high and the rear grills have some dampening on them. I do think this makes it not as airy sounding as some other open backs, not a huge issue for me but if you are fan of that real open airy sound it might be.
Aeon 2 is really quite nice for gaming too, I have been playing Mafia 3 lately and its given me a lot of appreciation for how good that games sound and soundtrack is. Playing it with the Koss didnt give quite the same visceral, real sound that the Aeon does. Just walking around in the game impressed me as the thud of combat boots on a wood floor sounded so real right down to the creaks from the old wood. Squealing tires and gunshots all sounded so damn good.
I should mention all of my testing has been done with a Creative G6, which is not ideal for the Aeons I think as its USB powered. It may not be getting the current it needs which could affect the bass extension or other things, I still think it sounds outstanding though. Gonna get a better amp in the near future which will make it even better I am sure.
I wholehardly recommend the Aeon 2 open to people who like a natural style sound and dont care about a massive soundstage. They are really amazing. I never tried the original so I cant compare unfortunately. I see a lot of people saying the original had a super compressed soundstage, so I think that aspect has been improved upon as I dont find it to be congested at all, separation of the various elements is outstanding.
I also designed a EQ to fix my slight issues with Aeon 2s response which took it from very good to amazing for my tastes. I am not using any tuning pads with it. I will put it below.
Preamp -3.5db
Low Shelf Filter 70hz +3.5db
Peak Filters
200hz Q4 -1db
4500hz Q4 +2db
5600hz Q6 -2.5db
7200hz Q7 -2db