James, perhaps you could pass on a few more details for us here? I don't want to go too far beyond layman's terms, but if you spent over an hour talking about this, then I sort of think you're obligated (to the group, and to Ron for that matter) to pass on a few more details.
In stereo systems, you find speaker designers who are adamant about using only first-order crossovers (arguing that these tend to be better at phase and time), and others who prefer fourth-order (possibly for more even frequency response and/or dispersion characteristics, but I'm stretching here). Maybe some thirds, not many seconds, I forget.
The concerns here, for hi-fi speakers, seem mostly related to the fact that you typically have multiple drivers in each enclosure, covering different frequency ranges, and therefore get some unfortunate phase cancellations around the crossover frequencies. Much of this seems to be based on distance between drivers, both vertically and horizontally, plus you have to think about the dispersion and interactions of two speakers in the room, and the resulting reflections and cancellations - something Ron dealt with on a much grander scale with the wall of sound. (There's a link to a great article on this, somewhere in here.)
Tied into this somehow, is the crossover slope - the rate at which output drops from one output, as it rises to the next. I'm pretty sure this is closely tied to the order of the crossover design, and typical slopes are 12 dB per octave, sometimes 6, and maybe 18 or 24.
if the crossover is steep enough (probably more than 12), then the range in which cancellation occurs might be small enough to mostly ignore. But if it's more like 6, then you could easily have an audible cancelling problem over more than an octave, which could be troubling.
There is another consideration, though I don't think this applies in most bass applications, because most cabinets either have a uniform set of drivers (e.g. 4x10) or they don't bother to include a crossover. But you probably still have to factor in the natural rolloff of the drivers, e.g. a good 2x10 is probably going to roll off below 40-50 Hz, and above 5-6 kHz. I think most drivers, in this range, tend to naturally roll off at about 12 dB per octave, but I'm also not sure about that. But somehow you have to think about whether the crossover slope is greater or less than the rolloff of the cabinets you are driving, because only one will really matter.
What we need here is some practical advice. Again, I don't have an F-1X or a manual, but my guesses would be something like this:
- If you are simply routing the outputs to two vertically stacked cabinets, you should reverse the leads to one of the speaker cabinets.
- If the outputs are routed to cabinets which are significantly spaced, either laterally or fore and aft (sorry, I'm a sailor, not a performing musician), then you might have to just listen, and figure out what sounds best.
- In this latter case, you can save a lot of time if you know what the crossover slope is, because it might (for example) tell you that you only have to worry about the range from 100-200 Hz, so you could focus your listening around a specific octave, or possibly less.
So James, based on your discussion, how would you expand on (or correct) these suggestions? Hopefully, the manual can be improved in the future.