Keep testing Mavin Air-X.... The silicone stabilizers close my ear chamber a bit more, which makes a slightly smaller sound stage but add a bit more bass impact I was looking for. Good! Then ordered Spinfit CP155 tips. They fit Air-X like a glove. The sound has noticeable changes, but not profound. It becomes more crisp, better instrument separation, and more bass texture. Surprisingly they add a sparkling treble as well, but not so that causes any harshness. So the sound signature slightly shifts from Ath-E70 towards Sennheiser IE800.
Bad call quality, even in quiet environment. Earin M2 and MW07 win handily for this. Also I was not able to pair Air-X with a BT transmitter to watch TV, probably due to the new chipset and stereo plus thing. M2 (AptX) and Sabbat X12 pro (AAC) pair easily and sound great. X12 pro keep amazing me. Their open design gives a good sound stage when watching TV, and with their long battery life I'm ready for Super Bowl!