Get the MOST bass without subwoofer --- ??

[basslover911]

I really dont want to add weight to the car (since I autox and stuff)... and I dont want to remove it everytime I autox (every week)..

SO

Would adding;
6-1/2" speakers up front
6x9 speakers in the rear

AND
Filter (through an aftermarket HU) the rear speakers to only pump out lower frequencies or even wire them to the sub output to produce much lower notes (since I've read that the rear speakers don't do much for stereo listening anyway)

?