updates the Echo Lineup and Introduces the Echo Sub, a sub-woofer for your Echo devices - Tech Raman

Echo Sub Review: Alexa, Goes Boom!

A Week With The New Echo Plus & Echo Sub

Echo Sub review: Echo Sub is $130, turns Echos into a 2.1 system - CNET

Echo Sub - Powerful subwoofer for your Echo - requires compatible Echo device : Devices & Accessories

Echo Sub review: Exactly what you need for Alexa-powered music

echo sub: Echo Sub review: No more bass complaints - The Economic Times

Echo Sub: Good Hardware Meets Limited Software

Echo Sub Review: An Affordable Subwoofer for Compatible Echo Devices

Technical Reviews Sumitomo Electric

Review: The tiny $129 Echo Sub is a huge audio upgrade