well, it's simple. If you purposely have some of the drivers, even one, out of electrical phase with the other drivers, then there is no way all the harmonic content of timbre will be produced because, by design again, out of phase firing of part of the frequency response will actively remove content. Those step reponse measurements are, in my opinion, accurate and revealing of what a speaker is and is not capable of doing. A 30,000 Hz bandwidth pulse reveals what is going on in the time domain and it is simply a matter of when that speaker manufacturers finally realize this is a gotta have spec. Nuff said.
