In this article, we'll tell you how to pair an echo sub with an Echo speaker to improve your overall audio experience.
Echo Studio review: finally, an Echo that sounds great - The Verge
Echo Studio First-Look: Apple, Google And Sonos Should Be Worried - SlashGear
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Echo Sub review: Exactly what you need for Alexa-powered music
Echo Sub review: Echo can finally go deep - CNET
Review: The tiny $129 Echo Sub is a huge audio upgrade
Echo Sub review: Echo can finally go deep - CNET
Echo Studio review: smart wireless speaker with 3D audio skills
and audio: Echo pairing and customer support - EDN