Amazon's original Echo set the mold for the budding smart home accessory packing the intelligence of the Alexa technology. Unlike the Echo Dot, the original Echo has a powerful speaker integrated within it, so Amazon didn't initially include support for external Bluetooth-enabled speakers.
However, the company has finally extended the same functionality found in the Echo Dot to the full-size Echo meaning you can connect to any existing Bluetooth speaker for audio streaming and Alexa playback. This allows you to connect to more high-end speaker systems as well as utilize wireless, battery-powered Bluetooth speakers in the center of a room without the reliance on a constant power connection.
The process of connecting a 3rd-party speaker to the Echo is rather simple and done through the Alexa mobile app. Once you've opened up the Alexa App > go to ‘Settings' > tap your Echo device > Bluetooth > pair new device.