Please remember that you need truly isolated room from the outside sources of noise.
You wouldn't believe how really quiet noise sources can change whole graph.
There are different techniques of measurement known from 60 years or so. If someone is interested in the topic i would suggest to find few different norms (is it right word?) for acoustical measurements of transducers.
You wouldn't believe how really quiet noise sources can change whole graph.
There are different techniques of measurement known from 60 years or so. If someone is interested in the topic i would suggest to find few different norms (is it right word?) for acoustical measurements of transducers.