This thing is great. so much better for running around my shop while connected to the desktop audio. it reaches pretty far too. The quality is acceptable, the build quality of the device is spot on. it's seriously impressive how they've matched the finish so well. The only con is the micro usb rather than usb c, but the overall functionality of the device still leads me to give it 5 stars for the price and fit.
The AAC Bluetooth means with Apple devices there’s no decode/recoding - the results are actually better than a wired connection to the 6s (the last 3.5mm jack equipped iPhone). Fiio know how to make excellent converters and headphone amps. This might not be high end, but paired with the flat profile of the athm50x it doesn’t miss much that my reference mastering-grade midfield monitors offer, and the best I’ve heard from my m50x’s. It’s great to hear that flawless m50x bass delivered an optimal signal.