I recently upgraded my system from a Pioneer 5.1 receiver, to a Marantz 6.1 receiver. As i already had my speakers in place for the 5.1 system I needed only one more speaker for my rear surround. As you know buying a single speaker is somewhat difficult, and I let the sales rep talk me into a centre speaker. Then I started to think (I don't know very much about speakers) am I missing out? Whats the difference between a centre speaker and a rear surround anyways? The centre was relatively inexpensive, but I am just wondering?