Does dual camera recording work with the microphone?
Yes, and the important detail is that you get one audio track, not one per camera. The two cameras produce two video streams that are composited into one image; the microphone produces a single audio stream that is written alongside it. There is no such thing as “front camera audio” and “back camera audio” as separate things you could balance later.
That single fact drives every practical decision below — how to shoot an interview, where to point the phone, and what you can and cannot fix afterwards.
One track, and what it is made of
DualCam writes the audio as a single AAC track at 44.1 kHz, mono, alongside the video in the same MP4. Mono is a deliberate choice for this kind of footage: a phone held at arm’s length in a room does not produce a stereo image worth preserving, and a mono track is smaller, more predictable, and impossible to get wrong on playback.
The source is the device’s default audio input. That means if you have a wired or wireless microphone connected and iOS has selected it as the input, that is what gets recorded — the app does not override the system’s choice.
Why you cannot get separate audio per camera
This is a question people reasonably expect to have a yes answer, because there are microphones at both ends of a phone. But the capture session takes an audio device, not a camera-associated microphone pair, and the device delivers one stream. Directional pickup on a phone is a processing decision made below the app, not a set of independent channels an app can split apart.
For an interview where two people are on opposite sides of the phone, the practical consequence is that both voices land in the same track at whatever levels the room gives you. Get the phone closer to whoever is quieter, and do not assume you can rebalance them later.
Mute has to be decided before you press record
DualCam has a silent mode that records video with no audio track at all. It is not a volume control applied afterwards — when mute is on, the audio track is simply not created in the output file.
That is why mute is locked once recording starts, alongside resolution and the countdown timer. The structure of the output file is fixed at the moment writing begins, and you cannot add a track to a file that is already being written. Decide before you hit record: silent for b-roll, screen-free time-lapse-style clips, or anything you plan to score with music later; unmuted for everything where the sound is part of the content.
What changes and what does not, mid-recording
- Locked once recording starts: resolution, mute, countdown.
- Free to change while recording: layout, picture-in-picture corner, inset size, inset shape, colour filter, and which camera is the main one.
If microphone permission is denied
A dual-camera app needs camera permission to function at all, but microphone permission is separable. DualCam treats it that way: if the microphone is unavailable, the entire audio path is skipped when the session is configured, the app forces silent mode on, and recording continues to work normally as video only. You get a usable file rather than an error screen.
If you later want sound, grant microphone access in iOS Settings and restart the app so the capture session can be rebuilt with the audio input included.
Getting better sound out of a phone
- Distance beats everything. Halving the distance to the speaker helps more than any setting.
- Kill the room noise you have control over: fans, air conditioning, a television, a fridge.
- Do not cover the bottom edge of the phone with a hand or a mount.
- Avoid placing the phone on a surface you will touch. Knocks travel through the table and into the microphone.
- Hard rooms with bare walls and glass sound worse than rooms with soft furnishing. If you have a choice, choose the sofa.
- Wind is unrecoverable. If it is windy, get physical shelter; no processing will bring the voice back.
Common follow-up questions
Can I record silently?
Yes. Mute records with no audio track at all. Because the track is created when recording starts, mute must be set before you hit record.
Will an external microphone work?
The app records from the system’s default audio input, so whatever iOS has selected as the input is what gets captured. The app does not provide its own device picker.
Is the audio stereo?
No, it is a single mono AAC track at 44.1 kHz written into the same MP4 as the video.
Can I mute one camera and not the other?
No. There is one audio track for the whole recording, not one per camera, so there is nothing to mute separately.
Want to just do this?
DualCam records the iPhone front and back cameras at the same time and writes one finished MP4 while you shoot. Free, no account, no ads, nothing leaves the phone.