iPhone not picking up sound from Nord piano 5

[Engineer_Patrick]

Hi folks, newbie here. Just got my piano 5 and encountered some problems that really need help.

My setup is very simple and I just want to record video on my iPhone and pick up the audio from my audio interface at the same time. I have a focusrite 4i4 connected to my iPhone. A condenser mic connected to INPUT1 (front panel of 4i4), piano 5's LEFT and RIGHT OUT connected to INPUT 3 and INPUT 4 respectively (back panel of 4i4). OUTPUT 1 and OUTPUT 2 are connected to my monitor speakers, and I connected a DT 770 PRO as monitor headphone.

Problem is the recorded video only has my vocal but has no piano sound. However, if I connect piano 5's LEFT and RIGHT OUT to INPUT 1 and INPUT 2 (front panel of 4i4), iPhone is able to pick up the sound. So it seems to me that the issue is iPhone wouldn't pick up sound from INPUT 3 and INPUT 4 somehow. While recording, I can hear both my vocal and piano sound from my monitor speakers and the monitor headphone. So really confused what's going on for my setup.

Please advise if you have any idea, thank you!!!

[analogika]

Whatever video recording app you’re using is only able to record tracks one and two (the regular main stereo inputs)

You either need to mix down the audio into two channels before it’s routed to the video recorder (either this can be done directly within the interface, or perhaps there is a way to do this via Audiobus?), or record multitrack audio in an audio recording app and mix it and add it to the video later on.

[StrangeAeons]

I second analogika: have you tried recording through Garageband or Cubasis? Since they're the most advanced DAWs available on iOS (for now), they're your best shot at getting your iPhone to recognise all of your Focusrite's inputs.

[analogika]

I second analogika: have you tried recording through Garageband or Cubasis? Since they're the most advanced DAWs available on iOS (for now), they're your best shot at getting your iPhone to recognise all of your Focusrite's inputs.

There's also Auria Pro, which is closest to ProTools on iOS.

[Engineer_Patrick]

Whatever video recording app you’re using is only able to record tracks one and two (the regular main stereo inputs)

You either need to mix down the audio into two channels before it’s routed to the video recorder (either this can be done directly within the interface, or perhaps there is a way to do this via Audiobus?), or record multitrack audio in an audio recording app and mix it and add it to the video later on.

Thank you, I ended up with mixing everything through a mixer and then connected the mixer's stereo outputs to the audio interface.