In order to stream Spotify to the Audioengine B-FI or A1-MR, Spotify requires a paid Premium account. This unlocks the Spotify-Connect feature within the app to send the audio to your Audioengine B-FI/A1-MR.
A single device using a personal (1 user only) Spotify Premium account cannot play multiple songs simultaneously. However, this would be possible with a family plan and more than 1 device (B-Fi or A1-MR) though.
A single device using a personal (1 user only) Spotify Premium account cannot play multiple songs simultaneously. However, this would be possible with a family plan and more than 1 device (B-Fi or A1-MR) though.