For the next step...I took a piece of 1/4 pvc black plastic, a piece of 3/8 inch mdf and measure my cutouts for my speakers. In this case, I am using a pair of CDT Audio 2" accent fill speakers.
For this install, they require a 2 1/2" opening. But you can change the opening for whatever speaker you are using.
I marked the center of the opening in my frame for the speakers here...
And then drilled the 2 1/2 inch holes for the speaker mounts. I also drilled four holes along the perimiter of my mounting frame. They hold small 2 " bolts which will hold the entire assembly.
The picture just below that shows the PVC plastic faceplate with the CDT's mounted.
I then epoxied 2" PVC end caps to the back of my 1/4" mdf. These will be the chambers for the backs of these drivers and is what Ken at CDT Audio recommended for my accent fill...after that, I mock every thing up to make sure my assembly will fit together...