What phone are you using? My Pixel 3 XL automatically connects to the Mavin via aptX HD and did so from the first Bluetooth pairing with my phone, but I didn't realize it might not be automatic with all phones. I literally tried 3 or 4 different types of Comply foam tips and none of them worked because the bore size was always too small for the large nozzles on the Air-X. Per @mikp 's recommendation I went to aliExpress and ordered some "QKZ T400" memory foam tips that work well. They only seem to offer them in medium size, but I have large ears and they work ok. They're a pain to get on the nozzles, but they work because the bore stretches unlike the Comply foams. I also have found the Spinfit CP155 tips work well, but they can get pushed all the way down the nozzle so you don't get as deep of an insertion. The foam tips from aliexpress sound the best to my ears.