Left center and right center speakers

@erik_squires +1, looking good there on that CC you built

By bringing the center forward it will widen the dispersion area. I know you are tight on space but maybe just test it to see if that helps.

That is a GREAT question. I run two center channel speakers, one below the screen and one above the screen (top center), you can see the pic in my profile.

I would NOT do that with your two left over book shelf speakers though.

As for the BEST use of those two left over book shelf channels I would recommend using them as wide channels (again, see the pic in my system of the wide channels). You need to set them at a 60 degree angle to your MLP and you will love it. Make sure the tweeters are the same height as your front channels.

FYI

The extra channels are called Left and Right Wide, Height, and Back Surround, and each requires its own speaker. The Wide speakers should be located at ±60 degrees from the center—that is, well outside the main L/R speakers but still in front of the listener. The Height speakers should also be located outside the main L/Rs at an angle of ±45 degrees, and they should be raised above the plane of the other main speakers at a vertical angle of 45 degrees. The placement of the two Back Surround speakers is not well defined, but they should be directly behind the listeners.

Why add these channels? Audyssey's extensive research clearly indicates that human perception of directionality is much more precise in front of the listener than behind. Thus, expanding 5.1 to 7.1 by adding back-surround speakers is not nearly as effective as adding speakers in the front. According to Audyssey's findings, adding the Wide speakers is the most effective at increasing the sense of envelopment, followed by the Height speakers. Adding Back Surround speakers is the least effective because our sense of directionality is relatively poor to the rear—in fact, a single Back Surround speaker works perfectly well.

A demonstration this week at Audyssey's facilities in Los Angeles definitely showed the effectiveness of the system.

@dmaddox77 , if you want to widen the dispersion you can place 2D diffusor or combo panels on the front wall between the center and L and R channels (again you can see the example in my pic).

Remember, when you get the trinnov the room correction can be used to assist. When you take measurements make sure to take a couple where you seem to need more coverage.

If you post pics of your room it would help if we can see.

Wow! Looks fantastic, have you tried moving your CC forward away from the wall a bit?

Before you go for the trinnov get the pro upgrade for the Denon ($200 in msft store) and the calibrated mic they recommend (about $50) my system was night and day different when I upgraded my marantz processor to the pro version of audyssey.

You can use isoacosutic stands to get those speakers off the ground.