It's possible to listen to different songs in different rooms of the house. But every speaker will need to be connected to a different account within the family plan because it's not possible to listen on more than one location with one account.
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We think that it's best to talk to Amazon as they may have restrictions. If you're able to separate the speakers, or use a different Alexa account (and app) on another device belonging to the other family member, then you may be able to control one speaker per account.
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