Bluetooth? Maybe. Audiophile Headphones? Definitely.
I am going to split this review into two parts, Headphones and the Bluetooth receiver. This is due to the receiver being a separate piece included with the headphones rather than built in.
These are beautiful headphones, great looking and comfortable. The headband is memory foam lined and sewn together tight. The bottom of the band is plastic sealed, leading to a metal headband bent perfectly. The cans themselves are covered in plastic with a silver finish, looking really good with the tan pads and headband. I love the look, it looks quality. With all the plastic, it still feels nice, almost as premium feeling as it looks. It comes in a black box lined with satin, and with a 3.5 trrs to 3.5mm trs, a usb c cable braided nicely, and a 1/4 to 3.5mm adapter. These headphones come with a balanced single connection on the left cup! Balanced is a welcome touch at $300. The cable is nice, if a little long for portable use. But, you can use any 3.5mm cable with it, use one you like!
The Bluetooth adapter comes with one 3.5 trrs male to plug into the cans. A small plastic piece keeps you from connecting it the wrong way, it only fits in one way. Its perfectly formed to fit with these headphones and the weight of it is not noticeable. The bright AF LED is very noticeable, lighting up a whole dark room every time it blinks. It has a power button that doubles as a pause button only, and a power button. You can use these as USB to PC and charge it or hold the power button and not charge it, you chose! Its a nice feature to have control, as opposed to destroying the battery while using it in USB mode.
But Axel, hows the sound!? Awesome! Plugging these into my DX7s with the included 3.5 cable to 1/4 to 3.5 adapter sounds great!
The bass is what you expect from a planar headphone, their nano diaphragm sounds just like a planar while hitting at a cheaper price point. The bass is tight, present, and exactly how I like it. I like a tight bass that doesn't roll or sustain. You can get the sound I'm describing in the 770 pro, strong and over represented IMO. The Deva has exactly the bass I love from the $600 Aiva cans. The mid range is where the Deva is the boss. The mid range is forward, strongly presented, and perfectly accurate. These are my new mid range cans, nothing I've tried up to this point has beaten the Deva's mid range strength! The highs are clear, well presented, but not overpowering. While most people like a V-shape presence, i like a more neutral headphone with strong mid and high range presence and the Deva delivers. While I still prefer the high range on my Sendy Aiva these are easily the closest you can get to perfection at HALF THE COST!
The Bluetooth sound does not change one bit. But, here is my first complaint. These headphones are easily a $300 sound. The bluetooth adapter acts, lasts, and works like a $25 adapter. The weakest point of these headphones are the bluetooth. The bluemini puts out 230mw (in fact, as stated by their information) and 1125mw in theory. I can see the 230mw, but the quality suffers when you realize it lasts just under 6 hours (5h 50m in my testing before it beeps at me). As the volume control is given by your device (my DX7s to a bluetooth RX in my case) I don't feel that volume effects it too much. Freshly charged, I noticed the sound cutting out or quieting frequently. Soft songs do not present well through the bluetooth, rock and metal do find but soft INDIE music does not. Connecting to my Q5s or BTR3 fixed this issue and outperformed the Bluemini at every testing case.
I used Melanie Martinez as a early testing case for these headphones. "K-12" album by Melanie Martinez was my first test. All I can say is wow. The imaging is immaculate, incredible, stupendous, just perfect! The sound stage is close, but not as close as you would think. For many tracks on the album, it seemed like close (2 feet-ish). Some tracks really seemed wider, "Nurse's Office" was one of these cases. The coughing in the background sometimes presented within arms reach, other times 5 feet behind me. I don't know why this is, could be mastering or it could be the cans...
The last point I feel I need to make, why wireless open-back headphones? I feel the concept is lost on me, mostly. When I'm in my office, it doesn't make sense. Im sitting within arms reach of my DAC/PC/AMP and wireless seems pointless. But if I'm doing dishes, cleaning, sitting on the couch; I feel the ambient noise defeats the purpose. Taking these on the train or bus is out of the question, what is the use case? Its not a concept for me, but maybe it is for you.
Bottom line? Get these headphones if you are looking for a headphone that boxes at well above it's price point. These are $300 cans that fight at a $500 price. These give my Aiva ($600) a run for their money and will be a keeper in my home.
(Disclaimer: I purchased these direct from Hifiman's store. I did not get anything free, I was not asked for a review nor given any incentive for a positive review. The photo used is from google images, as I do not have a decent camera...)