Lead shot questions

Putting metal weights inside a speaker enclosure is obviously a misunderstanding of the concept of weighting down the enclosure by external loading.

But, it brings to mind an idea that I have been kicking around for a while, but never got to try. Carbon dioxide, CO2, is an easily obtained and non-toxic gas that is heavier than air. One could drill two small holes in a speaker, top and bottom, and fill the enclosure with CO2 (slowly from the bottom). After filling plug the holes, perhaps with a cork. The extra weight would not be enough to affect the enclosure structure, but it would change the enclosure loading of the driver, perhaps in a desirable way. If the effect is in the "wrong" direction, one could try Helium, but that gas would tend to leak out (whereas CO2 would not). Has anyone tried something like this?

Mboldda1, you are right, I have never heard of a problem, though I do find Elizabeth's logic quite sound (no pun). Keeping it bagged would require woofer removal but still no big deal.

Eldartford, can you elaborate on the misunderstanding? Does the weight get stacked on top of the enclosure? I have read a lot lately about mass loading the Von Schweikert VR-4jrs, is that not internal?

The CO2 is interesting and doable. I have a 20LB CO2 cylinder I use to force carbonate Beer kegs. Though, like most B & Ws, the CDM9s are a ported design. I do have the bung plugs. They are made from foam rubber and with the port low mounted, I feel that over time the gas would leak out. Drilling would NOT be acceptable. I could lay the speaker on its back, fill it via the port, then plug it. Blasting the CO2 in for a while would stir the air and facilitate a high CO2 saturation but it would not completely displace the nitrogen and oxygen.

Lead shot will kill the stage. Tom

you noticed that too, huh?

Working with one manufacture to tame a resonance in the bass range..They used mass loading in the cabinet to squelch the peak before the newly redesigned woofer arrrived for replacement. They asked me what I thought .."Speaker sounds coherent but slow and shut down..You need to take the lead out"..After the lead was removed the stage opened up and back came the speed. That was the first step..The second step is another story..Tom