The OPO has 3 mics, 2 channels, 1 noise canceling near the camera lens. I also have the same problem, the speaker does not work at all, no matter what app I try (different audio / video recording apps). The top speaker, which is in question, is soldered to the mainboard like a lid with the contacts hidden underneath and I don't know if I can replace the mic with a standard fine tipped soldering iron without melting the insides. Afaik you'll need a replacement motherboard but those aren't sold. Also I don't know if it is a hardware or software issue... PS.: I already broke the white seal, so my warranty is gone...