Gen III JBL/Nav dash speaker upgrade

I have a 2010 Prius with JBL w Nav 8 speaker system. The dash speakers ("squawkers") are only 2.5 inches and do not produce a true midrange. The door speakers are straight woofers and don't produce midrange at all. I have read you can fit a 3.5" (and possibly a 4") speaker in the same dash compartment, which I hope will produce more mid-range, but I have read on earlier posts that the JBL amp directly limits the frequencies sent to each speaker so my new dash speakers would be limited in their range. I don't want to spend the $$$ for a whole new amp and speaker set up. Does any one know if bigger speakers on the dash would improve the mids? Any one know what the frequency response is on the existing JBL squawkers? I called JBL and Toyota and they each referred me to the other. Thanks

 

Thanks for your response Rebound, but it doesn't really answer my question. I looked at all the pdf's and all 9 pages posted. The post you referred me to involved installing a new head unit ( including the dash speakers) on a model II. I don't want a whole new head unit install and my Prius is a Gen III with JBL/Nav, 8 speakers. The PDF from spiderman re replacing the dash speakers involves 4 ohm speakers with capacitors. Mine are 2 ohm speakers with frequencies determined directly from the JBL amp. The PDF might help with the install, but that is not my issue. My issue is whether it will make any improvement in sound if I just replace my 2.5" tweeters with a larger 3.5 or 4" speaker to get more mid-range, or whether the jbl restricts the frequencies so much that my new speakers will only be playing the higher frequencies. If any one has tried just the dash speaker replacement on a Gen III with JBL/Nav/ 8 speaker system, I would love to hear from you.