ATP3 to ATP5

hey guys is it possible to buy 2 more satellites and convert my atp3 into an
atp5???dus the sub for atp5 have more jacks(for more spkrs?) or its the same sub as the atp3?

this is the atp3:

http://www.alteclansing.com/product_details_intl.asp?pID=ATP3&region=asiapac&country_code=in

atp5:

http://www.alteclansing.com/product_details_intl.asp?country_code=in&region=asiapac&pID=ATP5