Jerryfreak those calibrators are very finicky about how well you seal the transducer in the collar and how far away the capsule’s membrane is from the transducer. I’m sure you are being careful and trying to be repeatable, but if you are not using a mount specifically made for the calibrator and mics you are testing, I’m not sure you can be confident in 0.5dB differences. Using it for directional mics is, as mentioned above, not a valid test.
Those Dayton Audio measurement mics look like they come from the same Chinese factory as the ones Behringer used to (still?) sell. Good value for a decently flat mic. You need a calibrator like the one Jerryfreak has to match their wild sensitivity differences if you want to match pairs or more. I ran 6 of those into a multiplexer for a few years before building a custom measurement set up using matched Primo EM72 capsules with calibration files.
An easy way to insure you place the mics in front of the source signal speaker in the same spot everytime, is to use a tight string stretched across the test area at the same height as the tweeter. Put a marker dot on the string right where you want to place each of the capsules. Place the capsules touching the dot on the string behind their grille. Just don’t bump into the string mounts.
You can get more complicated with laser pointers etc...
I’d like to see some of the impulse responses and freq responses when you start to take them. Good luck!
I run DPA4060 >> homemade 9V BB >> R09HR LINE IN all the time with my Jecklin disc and it works perfect for a wide range of music and loudness levels. Output at Max SPL (134dBSPL) is 2Vrms. That’s line level in my book.
. Hard to beat the size vs quality of this set up.
Miq