Thank you for the question! If the software is up to date on your SoundTouch 10, you should be able to take a source connected via the 3.5mm AUX input and send it to another SoundTouch system. Do you envision sending the audio to another SoundTouch 10 or a differnet system? Our wired input broadcast feature is currently in beta. We have an article HERE explaining. It sends the audio using Wi-Fi, however, and not Bluetooth. One thing to note is that additional systems will have a 2-3 second delay with this feature. Please let us know if you have any additional questions!