Hopefully the answer is simple but here goes: We record our services on vMix using MP4. We then edit and send them to Youtube. They play fine on a PC or tablet from our website (https://www.bethesdabchurch.org/sermons), Facebook, or Youtube. However, whenever someone attempts to access them on a smartphone (iPhone or Android), the audio is garbage. I also attempted to play the unedited file and the audio is still garbage. We also use an older Panasonic camcorder for Sunday school class recordings and they sound fine from any source. Any suggestions as to what I might try? Thanks in advance!