Wah Sound From CBUs

I've been thinking about it and I think I know what brings the "wah" sound from some CBUs. I didn't brace the back of my first CBU because I thought hey, the sides are 1/4 inch thick.. why brace the back. Well, i think he back not being braced is what's creating the wah.
If you've built a CBU with wah let me know what you think.

Vic, I think you're right that the missing bracing could cause - or at least add to - the wah effect. The brasiliana we recently built has this effect and also has an unbraced back. We were thinking along the same lines: not very big, sturdy sides, sturdy back wood, why bother....

On the other hand, if you check closely you will find that most acoustic guitars, ukuleles, etc. are dampened to some degree when you hold them against your chest. But the difference - between holding the back on or off your chest - is normally not that big, so you don't get a real wah effect.

This brings us to the subject of posture, how to hold your uke, different grips and positions, etc. - but I guess that's best left to another thread and might be more interesting for the players than the builders.