Keavin,
While I truly appreciate your enthusiasm, I have some problems with your physics - not all of them, just some. And before I say anything more, I should note that I have a (solid) Rogue and only once, very briefly, played a Series bass.
Nevertheless, I'll just go ahead and state a few things as 'fact' and let others contradict me :-)
This is way too long, so feel free to drop out along the way. The main point I wish to make is that while there are many good reasons to buy a Series bass, the fact that it has a chambered body is not one of them (aside from keeping the weight down).
Point 1: Series basses sound different than other Alembics primarily because they use a different pickup design (single coil) and somewhat different electronics.
Point 2: In response to the original question, my personal sense is that for a solid body electric bass, mass and stiffness are more important than most other things. Different woods will certainly affect the tone, but on average if you just look at weight/mass/density, that will generally give you a good characterization of the overall contribution of the body to the tone.
For a deeper (more fundamental) tone, bigger is generally better, though I would first spend my weight and dollar allowances on stiffening the neck, because that will make much more difference than the body.
I should add that I personally believe there are some special cases here, such as the high oil content of coco bolo, possibly things like the long grain structure of vermillion, and so forth. But to put it in crude terms, I'd rather have an electric bass body made out of a heavy lucite or plexiglass (maybe Corian!) than balsa. And I would prefer that neither be hollow.
My sense is that a larger, more massive body will mostly allow the strings to continue to vibrate longer and in more interesting (harmonically useful) ways. The simple theory here is that the energy remains in the strings, rather than being dissipated into the body.
Hollowing out the body, and thereby reducing its mass, would actually be counter to that purpose.
This is a complicated issue. We had some inconclusive discussions on this about a year ago relating to the 'hippie sandwich' constructions, and one of the questions there was: assuming the energy from the strings somehow bleeds out into the body, how exactly does it make its way back into the strings - because that's the only way it can possibly get amplified?
My current thinking is that virtually none of the energy makes it way from the body back into the strings, and therefore the more important question is what frequencies get lost more easily in the first place.
Point 3: there is simply no significant relationship between the construction of a Les Paul and a Series bass. A hollow or semi-hollow guitar body is constructed of fairly thin and flexible plates, with a sufficiently large air cavity that the air vibrations can interact with the plates, and in turn somehow modify the behavior of the strings.
This is a bit problematic... but more on that in point 4. For the moment, I would note that while a Series body may be partially hollow, the air cavity is too small, and the surrounding wood too thick, for the chamber to behave in a resonate manner that would reflect back into the strings.
Yes, you might actually feel it breathe (vibrate) a bit more, and that might inspire your playing and so forth, but you will have a very hard time convincing me that these small chambers actually affect the sound.
Point 4: an upright bass is a completely different animal, even more so than the Les Paul.
Assume you are playing an upright bass, without amplification, in a modestly sized room; or playing an electric bass in the same room with a small amplifier.
In both cases, anyone more than a few feet away from the instrument is hearing virtually zero sound from the vibrating strings themselves. Maybe some string/finger noise, like plucking attack or fret noise or fingerboard slap, but not the main tone.
With the upright, the strings vibrate, they move the bridge, which is designed to rock sideways and thereby transfer the vibrations to the top plate, which in turn excites an extremely complicated and interacting set of air and wood resonances between the cavity and the front/back body plates. This is what moves the air in the room so that you can hear the sound - air molecules pumping in and out of the sound holes, as well as being shoved around by the vibrations of the wood plates (a large surface on an upright). But you get remarkably little air movement from the vibrations of the strings themselves.
With the electric, it's completely different. Essentially all of the sound is coming from string movement, 'picked up' by magnets/coils and then amplified and sent out through a speaker.
Yes, the sound will be different depending on the woods, construction, and of course the electronics. But fundamentally, you are relying on an electro-magnetic sensing of the vibration of the strings, plus subsequent amplification and driving of a speaker cone, rather than a physical movement of air and wood surfaces, to produce the sound. The string itself doesn't move enough air, nor does the trivial vibration of the solid - or chambered - body.
So with an electric, what really matters is what you can do to modify the vibration of the strings, or sense those vibrations differently.
Point 5: I don't believe anyone at Alembic is going to claim that they hollow out part of the Series bodies so that it will sound more like an acoustic, or so that it will otherwise sound better than solid models. They need more room for electronics, want to reduce the weight, and maybe even some of it is just because that's how they've been building them for years.
It might be useful to read the description of the Classico (Alembic's electric upright). As you'll see, it has a hollow core to reduce weight, but everything about the design is focused on keeping the energy in the strings - not on trying to take advantage of a resonant air chamber.
I'm probably being too picky here, but there is no reason not to put Series electronics in some other solid body shape (as many people have) - you'll still get the Series sound. It is not going to sound less full just because you don't have a couple of small air pockets in the body.
-Bob
