This is normal when pairing two or more Rave 3S speakers via AuraCast, music plays through all speakers, but the wireless microphone sound only comes from the main (host) speaker. 

The included wireless microphone is currently designed to pair with only one Rave 3S speaker (host) in AuraCast setups, which means microphone audio routes only through the host speaker. We are continuously working to enhance product features and appreciate your understanding as we prioritize future improvements.

If you have additional questions, please contact us at service@soundcore.com for further assistance.