4ohm woofer 8 ohm tweeter standard crosov

The crossovers with the MB Quart set were designed *specifically for the tweeters (and woofers for that matter) that came in the component set. If you were to switch to the Pioneers, the crossover frequencies will be way out of whack.

https://www.the12volt.com/caraudio/cross.asp

Using an 8-ohm tweeter in a crossover circuit designed for a 4-ohm tweeter will drop the crossover knee frequency by half.  Meaning, if the crossover was designed for 1800 Hz with a 4-ohm tweet, placing an 8-ohm tweet in its place will change the Xover frequency to 900 Hz.  This may be very bad for the tweeter - indeed it may damage it - and it will certainly destroy the designed blend between the tweeter and the woofer.  Also, most passive crossovers include attenuation and filter circuits to match the sound of the tweeter to the woofer, or to create the quality of sound desired from the tweeter.  Changing the tweeter will affect these things as well.

in short, don't do it.