Replacing Speakers

I have an 04 with the stock JBL. Im not too impressed with the sound, its decent for a stock system but nothing mind-blowing.

I have a set of Alpine component speakers SPS-600C but currently the tweeters are installed in a different vehicle. My plan is to use just the woofers and replace the front door speakers.

I know that the speakers will fit in the Prius, but will it sound awful if I just upgrade the door speakers and leave everything else stock? I understand that my car has 9 speakers, (4 tweeters, 4 woofers, and a center channel speaker above the mfd.)

I know I really ought to replace at least the front tweeters, but I don't have the money now to get another set of components. Will replacing just the front door woofers ruin the other speakers? (alpines are 4-ohm)

I do have the crossovers for the alpines, is it possible to use this with the stock-jbl tweeters? or should I just swap out the speakers and use the stock crossovers?

So basically to sum it up, is replacing just the front woofers gonna cut it? Ideally I want to spend some money on a sub to improve the bass and call it a day. If I were to replace all the speakers Id probally need a new amp to power it all- more money than im looking to spend

 

if the JBL speakers are like the ones i have in my other car (01 Sienna) then the bass will be fine. Upgrading those to alpines helped a lot with bass, but the sienna was a lot quieter inside so im sure that helped. Im researching baffles and sound deadening, definitely gonna improve the acoustics of at least the front doors when I upgrade the speakers.

I found alpine tweeters for about $40 on amazon so Im gonna give those a shot, they look like they should fit. Im not looking for a lot of bass from the front speakers, I want to improve the clarity of the mids and highs- later on this summer I plan on adding a subwoofer to give me better low-range sound.

From what Ive heard the front speakers are higher quality than the rears, so ill probably swap them to the back and toss/sell the rears. I know some people don't use rear fill speakers but I figure that I might as well use the enclosures. Another idea im throwing around is enlarging the holes, installing soundproofing, and putting some 8" subs in there. Don't know how good that will sound so i gotta do some more research before I go down that path lol.