I am looking to combine the system sound with an external mic plugged into the microphone jack and send the combined audio output to HDMI. Is this doable on my Macbook pro. I have tried different things with sound flower and creating aggregate devices and such without luck. I am able to create a recording in Quicktime which has the sounds sources mixed perfectly. But, I want to be able to send this output live through HDMI. Any help is greatly appreciated.

1 Answer 1


If you are looking to combine separate HDMI video and audio into a single HDMI connection (to go to a monitor, for example) you need an HDMI Audio Injector

This device is separate from your MacBook Pro and will work with virtually any digital video source and either an analog or digital audio source.

As for getting the sound to/from your MBP, you will need a Mini DisplayPort to HDMI for the video and perhaps a USB Audio Device. Here are two products I have personally used with good success:

Mini DisplayPort to HDMI

USB Audio Adapter

You hook the outputs up to the HDMI Audio Injector and you should get the results you are looking for.

I hope that helps.

  • Thanks for your reply. Let me clarify a little more. The macbook pro is sending out Video and Audio (from youtube or similar program) through HDMI out. I want to add another source of audio (from an external microphone) to the same signal before it goes into the TV to play both the video and Audio. In other words, I need to add a source of two of audio on top of what comes out of the computer before it gets to the TV. More like an opportunity for sound mixing. But, that would mean I have to buy a set of speakers that work with the mixer Jul 8, 2015 at 13:43
  • Do you want to do this live? Meaning you are going to put the additional audio on top of the streaming Youtube as it happens on the fly? Or is this something that is going to be prepared in advance? As for the speakers, I don't see why you need speakers that work with a mixer. Any 4ohm speakers should work.
    – Allan
    Jul 9, 2015 at 2:37
  • Yes, Live. I think I figured this out. I downloaded a program called Audio hijack from Rogue Amoeba and you can define how you want the sound to flow. I chose mic as one input, safari as the second input (all graphically on the app) and chose the HDMI as output and it all works seamlessly. No mixer or speaker Jul 9, 2015 at 3:17

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