Where to add sound deadening mat? For adding door speakers and under carpet

[traut811]

Good morning everyone.

I pulled the lower door panels off my '67 C10 and found out someone cut holes for a 6x9 speaker with what appears to be a hammer and chisel, probably the reason a carpet lower panel was added to cover it. I'm making patch panels now to fix all the ugliness, to turn around and cut holes for a 6.5" door speaker. I would like to add sound deadening material inside the door.

Where all is recommended to put this? I know I need right behind the door speaker, but do I line the entire inside of the door, outer and inner skin? I plan to do under the carpet as well, and I guess up the back wall also. I ordered 50sqft of the 50mil kilmat this morning so hope to tackle it this weekend.

Thanks in advance for any advice or suggestions.