These are the user forums maintained by measurement software manufacturers.
Rational Acoustics – main forum page
Metric Halo – Spectra Foo forum
The following are threads from various public usergroups related to audio measurements. I’ve come across some random threads I think are worth reading. If you have a suggestion for one you don’t see here, contact me.
Sound Forum thread about how many mics people use – condensed version
Sound Forum thread about how many mics people use – full version