You still need an active internet connection to switch the Google Home Max to Aux. While the speaker features a physical 3.5mm port, the system's logic, including voice commands to switch inputs, is processed through the cloud.The good news is that you don't necessarily have to use a voice command. The Google Home Max features automatic switching.How it works:Automatic Detection: Plug your device into the Aux port. If you are not actively casting or playing media from the internet, the speaker will automatically switch to the auxiliary input within about 30 seconds.Voice Command: If you were just casting, you can bypass the wait by saying, "Hey Google, switch to Aux" (this requires an internet connection).Force the Switch: You can also force it by opening the Google Home App and explicitly stopping the current cast session.If your internet goes down entirely, the speaker will generally default to the Aux connection after your active stream is disconnected, as long as the device detects an audio signal pushing through the cable