Adding Center Channel


I currently have my 2 channel providing the Audio for my projector. Unless I turn the volume up significantly the dialog is too low. I was told adding a inexpensive AV Receiver and center channel would help, so I did. I purchased a Marantz NR1607 and Monitor Audio Gold center channel. The NR1607 is used to drive the center channel only. The problem is I hear dialog through my main speakers before I hear it through the center channel. It almost sounds like an echo. I've tried everything and I can't solve the problem. Is it because I have two different amps(1 driving the main speakers and the AV receiver for the center channel)? I've contacted Marantz and Oppo via the phone and they couldn't resolve the issue. Any suggestions?
ricred1
"Prior to getting the center channel and AV receiver, the sound was coming through my 2 channel system."

So?  Do you get a strong center image for a soloist in stereo?  If so, why should HT dialog be any different?  I'd look elsewhere for the problem.

Yes, I  have great imaging/ soundstage with 2 channel. I've already added the center and AV receiver for when I'm watching TV or movies. There is a significant difference with the center channel.  When I listen to music I turn off the receiver/ center channel.
I'm thinking of trading up from the Monitor Audio Gold C350 to the Platinum PLC350 center channel speaker. Has anyone compared the two? I don't have the opportunity to compare the two and would like some feedback. Any thoughts on the value of expensive center channel speakers?