I don't know how high the midranges are crossed to the tweeter, so I can't comment on that. But there shouldn't be a real issue unless it's over 3 kHz. As for the lower crossover point, you have to cross low if the woofers are on the side. Otherwise they will beam to the sides and you won't get a proper blend in the front listening position. So 160 Hz isn't a design flaw--it's a necessity. Is this an all-passive system, or are the woofers actively driven? It's quite difficult to achieve a 160 Hz crossover point passively, but if they've pulled it off, more power to them.
Dennis, you and I know you never really do pull that off. You end up with huge inductors and caps. Unless the inductors are very expensive you end up with high insertion resistance which really changes system Q and upsets tuning. You also end up with a an amp buster load and big amp stresses.
I gave up that road long ago. If you really need to crossover that low a semi active or fully active speaker is required. I think for passive designs a crossover point of 350 Hz is pretty much as low as you should go. I do will not do passive designs lower than that and have not for a long time. The trade offs are just not worth it sonically or economically.
The next issue is that unless the speaker is truly a full range one, and I can tell you having done it, that is a huge undertaking, that the speaker is going to be used with a sub. Then you have a situation were you have crossover points an octave or less apart. That is never a good thing, as it makes for an almost impossible perfect integration. Good designs, use the highest bandwidth drivers possible in the mid range and get the crossover points as far apart as possible, three octaves preferably.
So I agree totally with the AVS poster.