At last ! I was personally waiting for those kind of results for a long time, and this is just the first ones out of the lab. The question asked here is : what would be the contribution breakdown between shell radiation and head radiation in the total sound of a snare drum ? The curves above show, for a snare played in an anechoic room, the vibration spectra (FRF to be precise) of the top head (red curve), bottom head (green curve) and vibration at two location on the shell. No surprises, below 1500 Hz (try out to filter a snare sound hi passed at this frequency you ‘ll realize you have lost quite some sound) the heads are way above the shell (we are talking a factor 10), and this would be a factor 1000 below 750 Hz…The snare used for this test is a hi-end instrument 14×6,5 Mahogany shell (with reinforcement rings, so not exactly the hardest shell you’d find ou there)….
Measurements of the « emissivity » of top, bottom heads and shell for various snares. X axis : Third octave frequency band, Y axis : % of potential participation to the global sound under external excitation
Participation of the various components under a « calibrated hit » made with a stick attached to a robot arm, for various drums.