Sony 4-130-031-11(3) User Manual

This receiver allows you to use a 5.1 channel 
speaker system. To fully enjoy theater-like 
multi channel surround sound, be sure to 
connect all the speakers (two front speakers, a 
center speaker, and two surround speakers) 
and a subwoofer (5.1 channel).
You can place your speakers as shown below.

AFront speaker (left)
BFront speaker (right)
CCenter speaker
DSurround speaker (left)
ESurround speaker (right)
FSubwoofer

Since the subwoofer does not emit highly directional 
signals, you can place it wherever you want.