Four Titan Kicker speakers total, 2 are the mid-bass (6") and 2 are the co-ax's (6.5"). Don't hold me to the sizes but they are all around the 6"-6.5" range.
Ty, I added the second set of Infinity Reference speakers and the new Boss amp and I coudl here it riding behind it today. I think I need to get the settings on the amp dialed in, but it sounded pretty good. I will have to try to get some more pictures of the new set up with 4 speakers.