For a single speaking voice, mono is usually the simplest place to start. A centered mono track keeps the voice anchored in the middle of the mix and avoids recording empty or distracting stereo space when the subject is just one person. Shure describes mono cardioid as a useful choice for recording one person speaking, while its stereo mode is intended for capturing a wider sound field. Shure’s creator microphone guide

When mono works well

Use a mono track for a single lavalier, a boom mic focused on one speaker, a voiceover or a one-person vlog. In the edit, place that voice in the centre and adjust its level so it is clear above the music and background sound. If you record two people with two microphones, keep each mic on a separate track when possible. That gives you control over each speaker before you build the final mix.

When stereo helps

Stereo can be useful for an ambience recording, a live music performance, a wide outdoor scene or a two-person conversation recorded with a stereo microphone in a suitable configuration. It can communicate space and movement. It is not automatically better for speech: a stereo field that wanders or contains distracting room noise can make a simple voice harder to follow.

Shure’s guidance is a useful default, not a universal law. Your mic, app, camera routing and intended playback all matter. Check how the track sounds on headphones and on a phone speaker, especially if viewers are likely to listen on small devices.