So I figured that if I measure the horn paths I could easily calculate delay for system time alignment, but I just read an article saying I need to account for the 360degree phase shift cause by LR-24.

How do I do this?

My system is 4-way:

SUB: BW HP 30hz, LR-24 LP 127hz, 50"hornLength

LOW: LR-24 HP 127hz, LR-24 LP 440hz, 30" hornLength

MID:LR-24 HP 440hz, LR-24 LP 5.5khz 10" hornLength

HI: LR-24 HP 5.5khz, off, 8" hornLength

What polarity setting and delay do I need

to properly time align system when using LR-24?

It is not that simple.

As you change freq-the "delay" (phase shift) of the filter also changes.

This is easily seen on a measurement.

And when you are figuring your "horn length", what is this based on? The actual length of the horn? or a distance to some point in space.

If the horns do not occupy the same physical space (and that is NOT simply being in the same cabinet) then the distance to a person listening will be different for each horn.

And once you move the position of the person listening-the distance from each horn will change.

You have to figure out "what position is most important" and go from there-and just accept the fact that all the other listening positions will be "off". No way around it.

The problem is that phase/delay is not something that is an "easy question".

You also need to account for the phase response of each particular driver.

That is why it is SOOOOOO much easier to simply measure and see the phase response than to attempt to "calculate it"-especially when there are "unknowns" in the equation.

You can adjust the delay time in real time-see the results-see the interactions above and below crossover freq and so forth.