[on the client] add a local /etc/[pulse/]default.pa containing:
load-module module-tunnel-sink sink_name=rpi_tunnel server=tcp:192.168.2.13:4713 sink=bcm1
If you don't put a sink_name in, pulseaudio won't start. The sink refers to the sink name on the [server] side [determined via: pactl list | grep -C5 Sink | grep 'Name:']
M. Shetiya, N. Mane, P. Uplap, und P. Musale. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (3):
1421--1424(März 2015)