Recording quality

I intend to record with on OBS using OBS Cam (my Iphone), Ipad, one Canon camera, one external Mic at the same time. My computer is a MacBook air (2013 - intel core i5 Dual core). But I never get good quality on video, specially on OBS cam. Is my computer's hardware too old? Should I use thunderbolt instead of using USB to plug in the devices? should I have other video card?
 
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