Can you use two microphones at the same time for dual camera recording?

One input, no matter how many devices are nearby

A capture session on iOS does not ask which microphones are currently connected and mix them together; it asks the system for the current default audio input and records whatever that single device delivers. If a wired lavalier and a pair of AirPods happen to be connected at the same time, iOS itself decides which one is the default input right now — usually whichever connected most recently — and that decision, not anything inside the app, is what ends up in the recording. There is no setting in a dual-camera app that changes this, because the app is never shown more than one input to choose between in the first place.

What a two-person wireless mic kit actually does here

Two-person wireless microphone systems — a small receiver that plugs into the phone, paired with two clip-on transmitters, one per speaker — exist for exactly this situation, and they genuinely help. But to iOS, that receiver is one audio input device, the same as a single wired lavalier plugged straight in. Whatever the receiver combines internally before handing audio to the phone is what the recording app receives, and DualCam writes that into the one mono track every recording gets, the same as it would from the phone's own microphone. Two transmitters do not turn into two tracks you can separate afterwards.

What the kit genuinely buys you is proximity, not separation. A microphone clipped to each person's collar sits close to a mouth in a way a phone resting on a table between two people never does, and that closeness is most of what makes recorded speech sound clear. The two voices still end up mixed into the same track — closer to how a single boom mic captures a whole scene than to how a multi-track podcast setup works — but a clean mix of two close mics beats one phone mic picking up two people from a few feet away, regardless of whether the channels stay separate.

Why this isn't a setting waiting to be added

Recording separate, independently balanced tracks per speaker is a materially different feature from recording one track well. It needs the app to see multiple audio devices at once, decide which one feeds which track, and write a file structure that keeps them apart — closer to how a dedicated multi-track recorder works than to how a phone camera app works. DualCam's audio path follows the same rule as its video path: pull the current input, write it as one stream, alongside one already-composited video frame. It does not offer a device picker for audio, the same way it does not let you choose a different back lens mid-recording — some choices are locked in by the structure of the file rather than left to a toggle.

Getting two people to sound right in one track

• Put the phone, or the kit's transmitters, physically closer to whichever voice tends to be quieter — there is no fixing a balance after the fact.
• A two-person wireless kit is worth using for proximity alone, even knowing both mics land in the same track.
• If two independently editable tracks genuinely matter more than a single finished file shot in one take, record audio separately per person on another device and sync it in an editor afterwards. That brings back the alignment work that shooting both cameras into one file was meant to avoid, so treat it as a deliberate trade, not a default.