I am fortunate enough to own two Alembics. They're both walnut but they sound completely different (but neither of them sound like cardboard!).
My Custom 5 is 36 scale, Rogue body, Maple neck (w/ walnut stringers), Epic/Orion elecs, Mahoghany body and a gorgeous Burl Walnut top.
My Brown Bass is 30.75 scale, fretless, small standard body, Mahogany/Birch/Walnut neck, Anniversary elecs, Myrtle body and a gorgeous Walnut (maybe flamed?) top/back.
The custom has a bell-like tone. Both the high's and the low's just ring out and sustain for days. I can make this bass super bright by backing off all of the bass and boosting the treble and it doesn't sound harsh. OTOH, I can boost the bass and cut the treb and really get down in the basement w/o turning the tone to mush.
The BB has a very warm and mellow tone - but the highs can be a bit harsh if I don't back off on the tone filters. This bass is very good at getting an upright-type sound but it doesn't do a Jaco-esque tone real well. (That's alright, I'm not out to be a Jaco-clone.)
Everything about these basses is different EXCEPT the Walnut top laminate. Still, IMO, the main difference between the two basses is the sound of the neck wood. I don't think I hear the walnut in either of these two basses. But I'm certain that I hear the maple and mahoghany in the necks.
Kevin