[Kodhifi]

I signed up as a backer #634 on their Indiegogo campaign and pre ordered it for $249 back in March of this year. After many set backs and delays they missed their ship date of June 2018, then missed July, then missed August. The item finally arrived 9/6 and I have my initial impressions after a few hours of use.

Overall impressions so far: They have absolutely no coloration, no audible phase cancellation or sudden jumps in how loud something seems at certain frequencies. Their sound signature is similar to the HD650 with a robust but not boomy low end, clear but slightly recessed mids, but with much more detail in the highs without getting grainy or sparkly. They are one smooth customer. Their impulse response, or how quick they sound, is what I would expect from planars, and it's in the ballpark of my electrostatic headphones. Snares and kick drums have instantaneous attack, and the bass is full without being boomy. It lets you know it's there without dominating. Their voicing is very ear pleasing and easy to listen to without any fatigue. Detail and sound stage are stellar and these may be the finest close backed headphones I've ever heard. There is a bit of ear plunger due to the sealed enclosures and very soft leatherette earcups. Noise is passively attenuated, however it's not equal between left and right cups. The left cup lets noticeably more sound in than the right due to the large microphone input slot. USB and Bluetooth audio quality was great, and the 3d positional audio tracks as you turn your head left and right, but I don't see myself using that when listening to music. It attempts to simulate a set of loud speakers so that music doesn't sound headphony.

Build Quality: They are very light, height adjustments stay where you set them. The passive noise attenuation is not the same for both ear cups with the left cup letting considerably more noise in. This is almost non noticeable when the microphone is plugged in, but with the microphone unplugged there is a slot in the left cup the size of a AAA battery, and that seems to be where the sound is leaking in. Plugging that hole with a foam ear plug helps when not using the included microphone. The headband is plastic but the flexible, not breakable kind. Seems strong. Weight is light and non fatiguing. Cables snap into place and don't fall out. The included case is form fitting and light, but not very compact. Included accessories were USBC-USBC cable for mobile use, USBA-USBC for PC and charging use, 3.5mm TRRS cable for direct connection to phone headphone jack. Detachable noise cancelling microphone.

Bluetooth: They advertised the ability to connect to 2 Bluetooth sources at the same time but this feature was pulled at the last minute. Bluetooth audio quality using LDAC and a Galaxy Note 8 was as good as USB direct audio. Pairing was easy and straight forward and it allows multiple pairing and will auto connect to whatever it was last using. Controls such as track forward/back, play/pause, answer/reject all work wirelessly. Connecting to a PC Bluetooth without LDAC (A2DP) the audio quality was acceptable but it was not possible to change 3d profiles such as forcing 2 channel or hi-res mode. It is possible to turn off the 3d effect though. It does not allow listening to audio while recording with the microphone at the same time unless it's in headset mode, which is very low bit rate and sounds horrible as it's made for phone calls not gaming.

USB Audio - I couldn't get the headset to detect. I later found that the USBC cable that plugs into the headset needs to click into place. I just hadn't used enough force when inserting it. USB charging was straight forward and allowed me to use the headset at the same time it charged. Windows 10 detected it as an 8.1 sound card at 24bit/96khz, and the microphone device as mono 24/44.1khz. It is possible to change the listening mode from the headset itself and select between surround, 2 channel direct, and hi-res. 2 channel mode re-detects in windows as a 2 channel audio device and hi-res mode disables the 3d effect. Hi-res takes it a step further and re-connects to windows as a 2 channel 24/96khz stereo source. Audio quality was superb and artifact free. Adjusting volume on the headset turns windows mixer up or down, and at 100% volume it can make you deaf. The track forward/back/play/pause all work over USB. Switching between 8.1, 2 channel, and Hi-Res causes windows to re-detect the headphone as a new device which can cause problems for applications like Itunes or if done during a game. It would be like unplugging your sound card and plugging a different one in, and you can't do that in the middle of using it. One nitpick is that it only locks to 24/96, no support for 24/44.1 or other sampling rates, so I can't use wasapi mode to listen to ordinary 16/41 cd's in foobar. It's 2018 and DAC's should support all standard sampling rates.

Comfort - I have a very large head, and finding hats and sunglasses is always a challenge. The Mobius fit with 3 clicks out on each side and with room to spare. Cup pressure was on the looser side of firm and did not cause discomfort even after a few hours of use. After a 3 hour listening session there was a slight build up of humidity in the cups but not nearly as bad as other close backs I've used. The earpads use a protein leatherette covering and have incredibly soft memory foam. They are shaped to conform to your head and seal very well. There is a plunger effect due to the tight seal that may bother some people when putting them on or taking them off. I could probably listen continuously for an entire work day and not get sore or uncomfortable. L and R markings are silk screened inside of the ear cup making identification easy. The cups also swivel 90 degrees allowing for DJ type one ear listening or putting them around your neck when not actively listening.

Microphone: The mic has a bipolar pickup pattern and seems to use noise cancelling. Recording in a noisy room left a very clear and easy to understand recording. There is a high pass filter in effect as well with no bass in the recorded microphone audio, leaving a very clean, if slightly thin sounding vocal. Pop was somewhat noticeable but manageable with mic placement. The microphone quality over USB is stellar and almost as good as my Plantronics Gamecon 780 which has the best USB microphone audio of any headset I own. Microphone over Bluetooth was pretty bad with a lot of compression artifacts but this is a limitation of the Bluetooth HSP profile. Apt-X HD may overcome this limitation but I do not have access to test (As others have stated, this headset doesn't have Apt-X, only AAC , LDAC, A2DP, and HSP)

Music Listening and audio quality: I loaded up Foobar and listened to a variety of FLAC 16/44 and 24/96 tracks over USB in hi-res mode. Audio quality was superb with a very pleasant voicing, and not a single hint of coloration anywhere in the band. Bass is robust but not boomy, and the over all sound signature reminded me of my Koss electrostatics but with a bass boost, or my HD650 but with a sweeter and more detailed high frequency profile. The built in amplifier did not have ridiculous amounts of gain, but at full volume it can make my ears bleed. I found myself listening to most music at about 50% volume. The initial release of the headset was recalled in testing due to some complaints of audible hiss and a factory refit was done to correct it. I noticed no hiss or audible noise floor in my testing, even at 100% volume on very quiet songs. Drum cymbals sounded authentic, which is a trait of a good planar/electrostatic that most dynamic headphones (HD800 aside) cannot pull off. Separation and sound stage were fantastic. These are the best sounding close backed headphones I've ever heard. They do not sound close backed at all. Most close backs have issues with phase resonance causing massive peaks and dips at regular intervals during a frequency sweep, but I can hear nothing like that. There is active EQ which they have used to correct for any of those problems with the close backed design and I'm happy to say it works very well, and you don't even realize it's there, which is what EQ should do. There are several EQ profiles you can select from including no EQ. Their house EQ and FLAT profiles sounded almost identical, so there is not much trickery or cheating going on to make them sound as good as they do (Sony MDR1000x I'm looking at you). Passive noise attenuation was decent but below average for a close backed headphone. I found my Blue headphone and my Oppo PM3's to have better passive attenuation. There is also a strange issue with the left ear cup being noticeably noisier than the right. After testing I found that covering the bottom of the earcup where all of the dials and jacks were, stopped noise leaking through. This was with the microphone disconnected, leaving a AAA battery sized hole in the headset where it plugs in. This seems to be where most of the noise was coming from. Covering this with my thumb almost (but not quiet) made the noise levels equal between left and right. The overall impression is without the microphone plugged in, I keep fidgeting with the left earcup because my brain is telling me the earpad must not be on right and is leaking sound, even when it's on as good as it's going to get. This is a minor peeve, and largely resolved by leaving the mic plugged in when not in use. Since the mic does not swivel back and out of the way, it's inconvenient to do so.

3d tracking: Is it a gimmick? No. It's not 3d audio the way that gamer headsets are. It's 3d audio the way that a producer, or recording engineer might use them when mixing surround sound audio for games and movies. The on board 3d implementation is similar to a software plugin that recording engineers use for mixing surround audio without a complicated in room 7.1 speaker setup. It lets them look around a virtual sound environment as if there were speakers in the room. To put it another way, the Mobius does for your ears, what the Oculus Go (pan and tilt no depth) does for your eyes. When you turn your head in a VR display, it pans and scrolls the image to trick your mind into thinking an object is staying still and it's you that's moving. The Mobius uses an accelerometer and a DSP reverb to simulate how a speaker would sound inside of an ideal listening environment, and then it tracks how you look around in that environment and pans the audio to match, tricking your head into hearing an invisible speaker in the room with you, that stays in place even if you turn your head this way and that. I see it being a more advanced kind of cross talk that headphone users have used to simulate loud speakers on headphones. The DSP virtual environment is similar to listening to music on Dolby headphone, but of course it tracks your head as you move around in a room, turn your head to look at something, etc.

Application - The Audeze companion app is great. After installing, you are presented with a 3d representation of your head. Tilt your head up or down or to the side, the head tilts; head bang, it head bangs. It shows you how smoothly and quickly it is tracking your noggin in 3 degrees of freedom. Since the tilt, pan, and side tilt are all tracked quickly, it makes me hopeful that game developers will make use of it similar to a TrackIR to allow real time head tracking in games like iRacing and first person shooters. We have the headphones on anyway, this would be a killer app and save you from wearing a ridiculous hat for the IR sensor. It allows personalization of the 3d environment to your particular features such as head size, distance between your ears, etc. This is in the HRTF (head related transfer function) section and allows adjustments to head circumference, inter-aural arc, and changes to the size of the virtual room. These changes are written to the headset and will work even if unplugged from the computer. The tool also shows remaining battery life, status of headset mute and 3d audio. The Sound Profiles section allows you to quickly change among the 7 built in EQ curves, Flat, Default, Foot Steps, Ballistics, Music, Racing, RPG. My review was done with Default selected, which was described as Audeze's house sound. A little fuller bass, subtle changes to midrange. Pleasant. Flat is not night and day but has slightly more rolled off bass, slightly more midrange.

Best things: Planar dynamic sound quality with stellar voicing and lack of coloration, in a wireless headset.

Worst things: Inability to use VOIP at the same time you're gaming when using bluetooth. It can act as a Bluetooth headset OR a wireless music/game headphone but not at the same time. This is a limitation of Bluetooth though not the headphone. AptX low latency may resolve that problem but I don't have access to one. (My bad, it does not use APTX, only AAC and LDAC)

I also really hope they add support for 44.1 in hires mode and other sample rates for WASAPI compatability. My Soundblaster E5 had this same problem out of the box but it was later fixed with new firmware so I remain hopeful.

Updates - no aptx support, lack of 44.1 in hires mode, amended what is tracked in 3d mode, Added information about the Audeze App.