What is the stock (non-JBL) system crossover frequency?

Well the used 2017 Prius Prime I purchased has one bad left door speaker (I didn't notice it on the test drive, since I was listening for any odd engine noises), it just buzzes & rattles and doesn't make any useful sound.

Does anybody know the stock (base) system's crossover frequency and the slope (dB per octave)? And is the stock head unit or amp tolerant of a slight impedance change? Let's say I run a new set of door speakers from 3.4 ohms and greater, will the head unit shut down if the impedance gets too low?

I've never been happy with my stock system, the bass is too heavy at the "center" setting and I have to run my EQ with bass cut quite a bit while the midrange and treble have to be higher. The EE in me is chasing flat, hi-fi sounding frequency response, but the stagehand in me also enjoys some bass, just not booming bass like the stock system has, so I'm conflicted...

Should I run a speaker-level to line-level converter, feed a DSP, and install a whole new system? Or would I get decent, acceptable sound by just replacing the door speakers? Keep in mind I have 1 failed door speaker and still ridiculous booming bass at the "center" setting, I wonder if that means I have a failed tweeter too?

These are what I am looking to replace the stock door speakers with: C 165 - Hertz car audio systems | The Sound Experience

I hate the blingy, boomy, tuned for hip-hop car audio products from the major manufacturers, so I'm going to try and stick with manufacturers like Hertz, Focal, Morel, etc. which are much more hi-fi sounding if possible.

Thank you all and hope you all have a safe Memorial Day weekend!