Transmit & receive 4ch audio Answered

I am looking for a cheap solution to transmit and receive 4 channels of audio.

Transmitter may be bulky, but the receiver must be small. (it is for an interactive installation)

Audio The 4 channels will be converted to 2 channels stereo, so in total 2 stereo signals of audio need to be transmitted and received (within ~10 meters). Note that achieving the best audio quality is not of top priority.

Technique Should I be looking at FM / AM of Bluetooth methods? I've looked at: https://www.adafruit.com/product/1958, but it would be nice if there is also a paired receiver board.

It would be nice if the proposed solution is scalable to 6 channels (3 channels stereo).