Both the HT1s and HT3s include two pairs of binding posts in their default configuration, which will allow either bi-wiring (2 wire runs per speaker from a single amp) or passive
bi-amping (2 wire runs per speaker from two separate amplifiers). For bi-wiring and passive bi-amping, the designer's passive crossover remains in the signal path and retains its normal function. Take a look at the first 3 articles on this site
for a description of bi-wiring and passive vs. active bi-amping.
I'm no expert on bi-wiring, but from what I've read, people generally seem to see an advantage to bi-wiring only when their initial single-wire run didn't offer enough total wire gauge to handle the current demands. I'm sure that the RLC values of the complete system may alter in some manner and thus have an additional affect, but I haven't yet found a source discussing it.