DISCLAIMER: This was a review tour unit provided by Fiio. Fiio has become an interesting beast in the headphone community, chiefly for their ability to pack a lot of fairly high-quality features into low-cost products. They've been tearing things up with their various portable amps and DAPs, so when they decided to dip their toes into the IEM world with the F9 and F9 Pro, I was excited to hear what they'd come up with. The end result? Good, but not great. I'm going to be stacking these alongside the KZ ZS6, 1More Quad, Mee Pinnacle P1, and iBasso...