Hello, I have a ONKYO HT9100THX home theater system and i have a extra HT9100THX speakers laying around, can i stack the front 2 speakers on one top of each other and connect both on each side to one output of L and then 2 on the R output on the back of the ONKYO? Is that a problem or no? And then similarly i will stack and connect 2 center speakers in on center output. Please let me know.. Thank you.