Hi! I use my phone*, as mentioned later on, held about 9" (20-25cm) under my face. The first recording was a bit quiet, so I turned the gain up 1dB for the second - which is still a bit too quiet for me. Don't want to spend much time thinking about the technical aspects, for that way lies ruin. ;)

*An Android: Sony Xperia Z5 Compact. App: Hi-Q Mp3 Rec (Free). Its paid version allows > 10 minute recordings, though I can't imagine what I'd talk about for that length of time!