I agree with crASH. A bell is
made to resonate. It's size, shape, material and thickness will all have a dramatic effect on the sound it makes, not to mention the hammer or mallet.
Suspend and iron, aluminum, FE, SB, etc. and see how they sound when struck. They will all sound a little different and have resonant frequencies but they probably won't translate well to the [glorius] sound of a BB and the [bothersome] noise of a SB.
I'd say it's the C/R, bore, heads, headers and pipes, even fuel probably, moreso than the mass of metal.
I wish the builders would chime in (no pun intended).
