Originally Posted by
fscotte
It adds weight, which changes the modal frequencies, and subsequently the tuning of the air chamber. If your chamber is tuned to 300hz, adding 15 grams of anything.. clay, wood, fancy carved wood thingie, will drop the frequency a bit to something like 296hz. That alone changes the timbre of the tone.
Anything else the virzi supposedly does, isnt supported by any evidence Ive seen. The differences one hears is likely due to the lower timbre caused by the added weight, which is provable and evident.