Streaming Audio to Multiple Wireless Speakers

Question

I would like to be able to stream audio from a raspberry pi to multiple wireless speakers in the same room (synchronized). I would also like to be able to control the raspberry pi with a computer or smartphone. My first instinct is to use MPD, but I am not sure if this is even possible. How would I go about implementing such a setup?

Answer 1

There are probably several alternatives to accomplish what you want, but one possibility is to use MPD running in a "server" raspberry pi (which may or may not have its own speaker) with audio output through pulseaudio, and then use pulseaudio to broadcast synchronized audio to your LAN over RTP to client machines connected to speakers, wirelessly or not.

Such a setup would require three independent but interacting pieces:

• MPD running on the "server" rpi, with audio output through pulseaudio. This implies adding and configuring the "pulse" audio output in your mpd.conf file:

  audio_output {
      type                    "pulse"
      name                    "MPD PulseAudio Output"
      sink                    "rtp"
  }
  

• A pulseaudio instance running on the "server" rpi, either as user or system session, with an RTP sink via the "module-rtp-send" module:

  load-module module-null-sink sink_name=rtp
  load-module module-rtp-send source=rtp.monitor
  set-default-sink rtp
  

• Instances of pulseaudio running on "client" machines (raspberry pis?) with the "module-rtp-recv" module:

  load-module module-rtp-recv
  

Configuration details are beyond the scope of an answer here, but you can find a decent how-to guide for MPD on the rpi here. An exhaustive guide on setting up RTP broadcast, specifically using raspberrys as both senders and receivers can be found here, and in the pulseaudio documentation.

I can confirm that this setup works, as I have done it. However, RTP is extremely demanding on wireless links so YMMV.