I often see a cylinder underneath the mic head on "studio" desk/podium mics from the 30s and 40s. They routinely appear to be around a foot or more long and 4 to 6 inches in dia. What porpoise, other than supporting the mic, did these serve?
The tubing can house a preamp for sure, but they also alter the microphone response.
A microphone is a "tuned system," much like a speaker or an antenna. While an antenna is unlikely to cover more than a few octaves, mikes and speakers do that. Everything about the structure and its housing impacts that.
Now they can be computer modeled, but the old mikes weren't, they were designed empirically based on lots of experimentation.
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