I went by Guitar Center today but the only XLR Y-adaptors they had were cheap (as opposed to inexpensive, which they weren't particularly), so I'll probably look at ordering something better online instead.
We'll see what happens when I get the splitters and let 'er rip, but my assumption is that I'll want to pad the bass even if it's just a little hot, because already the speakers are often on the edge of sounding more powerful in this room down low than I would ideally prefer. (I suspect that biamping, absent any introduced top-to-bottom gain imbalance, will probably tend toward alleviating this just by virtue of tightening things up a touch.)
I'd assumed it might be preferrable to attenuate at line level, if possible, rather than at speaker level, on grounds of sonic transparency and parts cost, but maybe that's wrong? But as for ease of installation, I don't think I would attempt the mod myself in either case, not being much of a techie or a solder-jockey. (And I have no way to measure complex impedances at the driver terminals to make calculations.)
I happen to live close by to the manufacturer of the amps, and maybe the possibility exists for me to have them modify the input sensitivity if needed. (I'm guessing that any added or changed resistors would follow the input trannys in the circuit and therefore wouldn't simply be done across the input jacks.)
My preference would be to not modify the speakers internally, so that comparative amp swaps could be made freely, which would rule out padding between the crossover and the woofers. I suppose an inexpensive external L-pad would be a good way to try things out for starters.
