Hi Peter, sorry I've been slow at thanking you for your generous reply. I've been running experiments trying to fully digest what you and Phil have been explaining.
I think where I've been hung up, is that I've been looking at it from the perspective of a signal spit into mutichannel passbands, with 'prewarping on each of those channels. IOW, from the perspective of tuning the DIYs.
It's hard to see how any reduced load on an amp channel occurs in this case.
But if I think about 'prewarping' a signal going through a single amp channel to a speaker with a passive crossover in place, I can kinda make sense of a reduced amp load. I've tried comparing a dirac pulse (which I take to be a good example of a highly organized signal !), before and after some FIR adjustment that could represent plausible corrections for a passive speaker, and I do see a reduction in peak amplitude, post correction. So I'm hoping this is a valid understanding of what you guys are showing.
And yeah, I remembered the square wave response in post #1 quite well. It prompted me many months ago to get an o'scope and arb function generator, to keep learning. I've got some pretty decent looking square waves from the DIY, but not quite so good as yours ....yours look almost electrical !!
