Comparing two audio interace mice pre's for self noise.
Preamps often have 1/F noise not white noise so the majority of the noise power you will read on a flat meter will be low freq, which will not always be audible.
A better measure of how noisy it _sounds_ would be to use A or some other weighting to make the measurement.
But it is also true, most eletret mics effectively have a built in preamp so I would also do a test with the actual mic you want to use as well as with the terminator.
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