I apologize for being a little vague here. I might be way off base in my thoughts. And I skirted the story a little to protect someone as well as not be an out of step a-hole. A little more to my question(s). I actually had a bass made. So brand new. It's really nice but heavier than I figured it might be. My one experience with a chambered bass was with a friend's Sadowsky, which was crazy light. So I may have had my expectations up higher than reality. I don't want to say who made my bass because I don't want to say something due to my lack of knowledge. I asked for it to be chambered and paid for that but maybe it was forgotten... or not and I'm just inexperienced at identifying a chambered bass..? I've tapped on it and my other basses and on a semi-hollow bass. I can't with confidence tell a difference other than the semi-hollow, which is obviously different sounding. So maybe the top horn is slotted similar to how Sadowsky's are in the pictures I've seen..? Under the pick guard on the bottom horn it sounded hollow so I pulled the pick guard back and found the control cavity to be larger than needed for a passive bass. But that takes weight off so it makes sense. Anyway, I have a friend who is a chiropractor and he has an ultrasound machine. I don't even know if it is possible to test for but I was curious. And I asked here in case someone had ever done that kind of test before.