Why did you think it wouldn't be stiff enough without the ribs?
 
Just curious.

Rowka,
It sounds like this is done to address the tone of the resonance,instead of any concerns about a lack of stiffness.
 I would guess the overall tone will now have a few small resonant peaks in the sound, instead of two.

Rick - inquiring minds would like to know ...
 
There was some discussion about the effect of the chambered body, and I think it was Malthumb who commented that the chambered body made the lows sound more like coming from a tuba. With a non-chambered body, the lows sounded more like coming from a grand piano.
 
Does the idea behind the rib have anything to do with that?

The rib has significantly less science in it than everyone is thinking and more qualitative estimate. I tend to like the sound of the long scale basses with smaller bodies than the larger bodies. After much trying of various basses and tapping on the bodies I decided that some of the tonal difference was coming from the more hollow sound versus the more solid sound of the smaller bodies. So I added the rib to get the chamber sizes down closer to the smaller body chamber sizes and limit the maximum span of the top and bottom. I also know that this may have had little to do with the differences i was hearing since most of the tonality is in the neck. And I added ebony to this neck, which none of the basses i tried had. Additionally, this bass body is a modified version of the previously featured Hot Lava body and Mica noted that it sounded great, but was a little boomy, so if the body chamber sizes were causing that, the ebony would likely make it worse by strengthening the lower resonance points.  
Soooo....I''m holding my breath and hoping the rib will move the tonality in the direction I want.

Fair enough.

Or you could simply adjust the filters and amp EQ and call it a day. The subtle differences in the tone due to the so called hollowed out section(s)has very little to do with some mystical resonance tone chamber(s) but everything to do with the overall mass of the instrument. You have a 1/4 top and back wood which would not get the air vibrating in the chamber(s)if you hit it with a sledge hammer. The hollowed out section is to reduce weight more than anything else with the disclaimer that everything is synergistic on any instrument. Need a nudge? Next time you tune up watch the needle, strike a string with and without your finger and thumb on the tuner. You will see a slight increase say 3 cents with your finger on it because it's adding mass to the instrument.

Top laminate getting prepared for it's future appearance on the bass:

Thanks Mica!

Wonderfull to see such jewels being born... Thanks, Alembic.

Been collecting more pictures for you over the past month, so here's a big pile of goodies!  In the pipe clamps:

  Bob mapping out the routing:

  And here routed:

  Back too:

  Nice sandwich:

  More in carving:

  Heart Omega partially carved:

  I'll upload the sealer coat images in just a few minutes... stay tuned!

Here's the bass with the sealer coats:

 

 

 

 

 

  I can't stress enough that this bass looks even more beautiful in person.

Wow!

I love how this wood glows with warmth.

Amazing top,
Nice neck recipe too!

It may just be that beautiful bookmatch throwing me off but I can't tell if this is going to be a balance 'K' or the older full size balance omega?
 
Graeme