This is what i did,
Changed the 6x9's to a pioneer champion series 6x9 3-way,
I run a kenwood 1000w 4-channel amp for the 6's and the 6x9's.
The splits are run through my head deck.
Ive also got a Kenwood Champion Series 10' Sub, running through a 1000w Kenwood Monoblock...
so far i havent heard any cracking or crumbling and it sounds very nice!

In total cost me about $800 to do this myself (got some mates who have done their systems so I didnt get charged for installation) but im guessing with installation and everything would have maybe cost close to $1000-1200