bandpass crossover on amp-questions

so i was looking at my jl 700/5v2 amp i had from my last truck, channel 3 and 4 can be high passed or bandpassed.
would i be on track to think if i had channel 1 &2 high passed at say 500hz, that the bandpass setting on ch 3&4 would then play from the then selected highpass, say 80hz on up to the 500hz freqency or whichever freqeuncy is selected on ch 1&2?

on the amp itself, it shows a dotted line connecting the freq. location of ch 1&2 to ch 3&4. as shown underneath the dials



If i am on track with my thinking, what would be a good base line to bandpass a 6.5 woofer at to cover mid bass ranges?

i am going to tinker with doing a 3 way setup in my front doors if this will work as i imagine it should.
why am i going to try a 3 way set up? for the fun of it.

the crossover i am going to use for the midrange/tweeter will take the mid range from 600hz-4500hz, and then the tweeter will take over the rest.

 

Yes, that is exactly how it works. Check page 9 of the user manual,

“BP” (High-Pass):
Configures the filter to
attenuate frequencies below the indicated filter
frequency and above the Channel 1 & 2 Filter
Frequency, at a rate of 12dB per octave. This is
useful for connection of mid-bass or mid-range
speakers in a tri-amplified system.

A good midbass baseline HP is 80Hz. Adjust up and down from there. If your midrange is capable, I would recommend trying to cross it lower than 600 Hz. Like around 300 Hz. That would ensure the mid covers the midrange and your midbass really handles the kick and impact instruments. Check this chart for an idea on the instrument frequency ranges. http://www.independentrecording.net/irn/resources/freqchart/images/main_chart.jpg

Ideally you don't want crossover points within critical music ranges. The crossover components cause phase shifts and sometimes time delays, which can make the sound incoherent. Good luck and keep us posted on your progress!

 

awesome. I knew I could make this work!.
and thanks for link to the instrument ranges.