Surround volume

hawgfan88
hawgfan88 Posts: 12
Why is the volume so low when I switch from stereo to surround. I am running a pioneer vsxd811s the only speakers hooked to it are my surround. my fronts are hooked to a separate amp which is connected to the front preout and my sub to the sub out. Please help.
Rti12's
Csi3
DSW Pro 600
Onkyo M-282
Pioneer VSX D811S
Belkin Pure A/V PF60
PS3
Wii
Philips 47" 1080p