3 channel stereo music processor

I have 3 identical Tekton S-Lores for my LCR. What is the best (most flexible?) way to process two channel stereo music to originate the center channel signal for listening without the rear surrounds. I know everyone says to listen to two channels. But my set up is strange thanks to my wife's mandatory furniture arrangement. At this point for digital manipulation for a center channel I am using my Marantz receiver. I am considering a Harman Signature Citation 7.0 analogue processor as an improvement. Dose anyone have a comment on this or a alternative that is not crazy expensive?