Mesa 12" speakers
 

Did mesa change the speakers that they were using in the walkabout scouts and Power House speakers

I can't speak to the powerhouse but they did change the Scout 12's from the Eminence Deltalite I to the Deltalite II's when Eminence stopped sourcing the I's to the public.

i went to there page and noticed that they didnt use neo's for the 12's anymore and it now says custom PH speakers

I know there were two versions of the Neo Powerhouse 12 as I owned a pair of Powerhouse 412 cabs at one point. The slightly newer cab (black grill) had much lighter weight drivers then the silver grilled cab. The silver grill cab was rated at 1000 watts and the newer one at 1200 watts. The older cab had a bit warmer tone to it. The newer cab sounded a bit more crisp and articulate. Both appeared to Eminence drivers. I noted my 2008 Walkabout Scout had the older heavier driver in it.