How Do I Play Audio On Two Sets of Speakers Simultaneously?

Question:

Fred asks: I have a USB device from Xitel now called MP3 Streamer (it used to be called HiFi-Link), that supposedly bypasses the onboard preamp. I’d like to to be able to play both the sound from the headphone out (connected to “local” speakers) and the USB (connected to my audio system) at the same time. I believe you spoke about this in an episode a while back. I tried to pull it off then and was unsuccessful. I use Rogue Amoeba’s Sound Source to switch from one output to another.

Answer:

Fred, you’re close! Rogue Amoeba’s Airfoil will do this. It will also allow you to (simultaneously) stream to other Macs or Windows machines around the house, as well.

First run the Airfoil Speakers app, go to its menu-bar menu, and in the Preferences tell it to play audio through your USB device.Then run Airfoil, capture the iTunes audio, and from the “Speakers” menu make sure “Transmit to Computer” and “Transmit to <networked computer name>” are both checked. Audio should come out of both simultaneously. You could also accomplish the same thing with Audio Hijack Pro, though it’s not nearly as obvious (but far more flexible).