2 Use a Separate Mic
Even the most stunning of videos can be completely derailed by bad audio. Thankfully, this problem can be easily fixed by using an external mic — there are a slew of options online. If you can’t get your hands on one, the iPhone’s mic is perfectly suitable if you get close enough to the subject or source. Otherwise, the ambient environment and room sounds will often drown out that audio.
Another easy trick is to use a separate iPhone to record audio. You can even use the native Voice Memos app to do so. You’ll just need to add the audio recording in during the editing process. Pro tip: clap at the beginning of each take, so you can have an easy reference point to sync the audio and video later.