Nick5 wrote in post #18655619
Without any scientific data to back this up, I will go with personal Human experiences on a drum kit. Certain size toms will resonate the snares on a snare drum when you play it. My 7x8 Tom when tuned properly would always cause the snares to rattle. Tuned in a certain note range or frequency. If tuned low and flat, out of tune, snares reduced, Just an awful tone from the Tom. All of the other toms not so much. There's always that one frequency, note range and frequency.
Years ago in 2009 when I bought my 70-200 f/4 L IS, my IS was "Louder" than all of the IS lenses at that time. 24-105 f/4 L IS and the 100-400 L IS. Was there something wrong with the IS. Why is it louder?
Then I went back to my drum kit. The IS has a certain frequency, note to it. The IS dropped into certain drum shells, lens barrels with different heights and widths will certainly become more or less pronounced. Thus creating more resonance. These two combinations will make it sound that the IS is actually "Louder".
Since then the "Louder" IS has never been a burden as it is not a burden when I play my kit and striking that 7x8 tom.
Like the sound of the drum and the images created with my 70-200 f/4 L IS Version1, a smile is always on my face.
Enjoy your new lens.
I've been a drummer for almost 60 years and my son plays professionally. First, I suspect very few posters here will completely understand your analogy of the sympathetic vibrations of the very thin snare side head (not the snares themselves) caused by other drums being struck. Actually, all the heads will vibrate to one degree or another sympathetically, as very thin membranes under tension tend to do. It's just that in the case of a snare drum, the snare side head is vibrating against the metal snares causes the sound you hear, but even when the snares are released the head still continues to vibrate. Vibrations from a lot of sources will create the same effect, most notably low frequency tones from an instrument like a bass guitar.
I believe practically everything has a resonance frequency which will cause measurable vibrations if the amplitude is high enough. I am sure there are engineers here who can define the process much better than I can.
Second, and more to the point of this thread, the very noisy IS of the original EF 70-200 L IS USM is not the result of sympathetic vibration, it is a artifact of the design. All sound is the result of vibrations. A change in barrel size might alter the sound and perhaps even dampen the quantity a bit, but the noise itself is not caused by the barrel vibrating. I haven't heard the Mark II version so I have no idea whether it sounds the same as the original version.