When first launched, Google received some pushback about the smart home speakers not being able to pair to an outside audio source like Amazon Echo. There was not even an AUX-out port so you could not even use an external speaker through a traditional 3.5mm jack. You could, however, use audio with a compatible Google Cast speaker or speaker connected to a Chromecast audio.
We still get no headphone jack with either Google Home, but Bluetooth support is now coming with the Google Home Mini (or Max). You will be able to pair a Google Home or Home Mini with a Bluetooth speaker so you can…