Is there a "rule of thumb" for the maximum MPH of wind that is acceptable during outdoor speaker testing?
Not specifically in MPH but on the wind created noise.
Make a measurement but without feeding any audio into the speaker, what you get will be the "noise baseline", you decide whether it´s acceptable or not.
As a side note, avoid wind hitting the microphone.
Minimum protection is the classic foam cover, even better set up some cloth barriers around.
Similar to this voice pop filter, but larger, just cloth on some kind of frame, all around:
Make a measurement but without feeding any audio into the speaker, what you get will be the "noise baseline", you decide whether it´s acceptable or not.
As a side note, avoid wind hitting the microphone.
Minimum protection is the classic foam cover, even better set up some cloth barriers around.
Similar to this voice pop filter, but larger, just cloth on some kind of frame, all around:
There's the big furry "dead cat" microphone covers, but I have no idea if they affect frequency response.
https://www.movophoto.com/blogs/movo-photo-blog/what-is-microphone-wind-muff-for
Some discussion here on DIY alternatives, and an explanation of why these things work:
https://www.vegascreativesoftware.info/us/forum/ot-making-a-diy-deadcat--93202/
If you're using digital magic like MLS, maybe it will also magically remove wind noise.
https://www.movophoto.com/blogs/movo-photo-blog/what-is-microphone-wind-muff-for
Some discussion here on DIY alternatives, and an explanation of why these things work:
https://www.vegascreativesoftware.info/us/forum/ot-making-a-diy-deadcat--93202/
If you're using digital magic like MLS, maybe it will also magically remove wind noise.