Don’t take this the wrong way but I really have to ask the question why do you think too much vocal is coming out of the woofers? What is the ‘correct’ ammount?
In a x.1 system where you have a separate subwoofer cabinet handling bass content absolutely avoid having vocal play through it.
In a multi way driver configuration within a single cabinet as long as the frequency range produced by each driver is loud enough, free of distortion and within excursion limits it really doesnt matter which driver does what as the entire cabinet sums together to make a single cohesive full spectrum signal.
My 2 way 6″ studio monitors cross over at 2500 meaning my woofers are producing most of the vocal range but at a comforatble listening distance i cant tell which frequency comes out of woofer vs tweeter.
Unless there are other reasons to alter the crossover e.g. different sized drivers overlapping each other too much at the crossover frequencies or you have dying or broken components in the current crossover I would suggest not changing it and make use of DSP on the signal feeding the speakers if you want to change the voicing of the speaker.
