Robert, the drum suspension system I referred to is called R.I.M.S., the letters standing for Resonance Isolation Mounting System. An L.A. studio drummer named Gauger invented and introduced them in 1980, and licensed the manufacturing rights first to DW (Drum Workshop), one of the most progressive drum companies around. R.I.M.S. revolutionized drum mounts, almost every company now using them or making their own version of the same principle. R.I.M.S. attach to the drumhead tensioning hoop rather than the drum shell, allowing the shell to freely vibrate, increasing it’s sustain (the length of time the shell "rings") considerably. A mount attached to the shell itself "chokes" the sound of the drum.
The term resonance in reference to a drum shell is in regards to the length of time it "rings", it’s sustain. But the nature of the construction of the shell also affects it’s resonance; thinner shells usually resonate longer and at a lower pitch than do thicker ones, the extra wood of thicker shells raising the shell’s resonant frequency (it’s "fundamental") and acting as a form of self-damping. The timbre of that resonance is a different matter, timbre being what civilians ;-) call "tone". Timbre is determined by the relative strength of the harmonics of the fundamental. Drums are not considered a "tuned" instrument (an exception being the tympani and Caribbean steel drums), the way guitar and bass are. That’s because drums produce so many overtones (not just harmonics, but intermediate notes) having as much strength as the fundamental itself, that the fundamental is hard to distinguish.
Drums used for recording often have damping applied to the heads, to change the sound of the drum towards the "tighter" sound you mentioned. Tighter in, ironically, having less ring, but in this case of the higher overtones only. The damping absorbs only the highest overtones, making the fundamental more audible. I saw studio drummer Jim Keltner (Traveling Wilbury’s, Ry Cooder, George Harrison, Randy Newman, hundreds of others) playing live on a sound stage in Burbank, and his DW’s rang so long the drum sound was a real mess---far too much sustain for my liking. The struck notes were not audible individually, each still resonating loudly as the next was played---one big, rumbly mess. The opposite of that is the sound Levon Helm of The Band is known for---"thumpy". Gene Krupa’s drums also sound thumpy on those recordings from the 1940’s, but that’s because plastic drum heads had not been invented yet. Plastic heads weren’t available until the late 50’s, and they rapidly replaced the calfskin used until then. Calf heads don’t need damping, as they already sound dead (pun intended ;-).
