When you're listening to audio on your iPhone, iPod Touch, or iPad, you can send directly to an AirPlay device, like an Apple TV or AirPort Express. However, if you've used this functionality, you know that iOS is unable to send audio to multiple outputs at once! We know many users wish to do this, and it is possible, with a combination of Airfoil and Airfoil Satellite. Read on for details on using Airfoil to send audio from iOS to multiple outputs. These instructions are written for Mac users, but they apply equally well to Airfoil for Windows.
It's not possible to send audio directly from an iOS device to multiple outputs. Instead, we'll use a two-step process. First, we'll send audio from iOS to a Mac running Airfoil Satellite. Second, once the audio reaches the Mac, Airfoil on the same machine will pick it up and send it out to multiple speakers.
Above, audio flows from the iOS device to the computer running via Airfoil Satellite. Airfoil Satellite is then captured by Airfoil and the audio is passed on to multiple outputs.
Step 1: Send from iOS to your computer
First up, be sure you've got the latest versions of Airfoil and Airfoil Satellite installed on your Mac. Launch both applications on the same machine. On the iOS device, tap the AirPlay icon in the audio app you're using (below left) or use the system-wide AirPlay control found in the Control Center (below right).
The Airfoil Satellite instance you're running on your Mac will appear as an output option, and you can choose to send audio to it. Here, we see Airfoil Satellite receiving audio sent by an iPhone. Now, the iOS device's audio will be audible on the Mac.
Step 2: Send from your Mac to all your audio outputs
With the audio flowing from the iOS device to the Mac, you're halfway to your goal of sending that audio to multiple outputs. This feat is ultimately accomplished with the help of Airfoil. In Airfoil, select Airfoil Satellite as the audio source in the menu at the top of the window, then transmit to any and all outputs you like. Below, you can see that the audio originally from the iPhone is being pulled from Airfoil Satellite and sent out to a Bluetooth Speaker, a Chromecast, and an Apple TV:
Now, the audio from the iPhone is being heard through multiple audio outputs throughout the house. Happy listening!