You can use any microphone for measurements. Taking into account various factors it has more or less utility. I have in fact made measures with a large diaphragm omni vs small diaphragm measurement omni, and there is little difference. I've made measures with a cardioid and those are okay until about 200 hz. So using the mic you have has usefulness as long as you know its limitations. And yes, beyond the range of proximity effect you'll get repeatable reliable measures with a directional microphone. I assume that is what you mean by stable after 1 meter. Down where we care the most, below the Schroeder frequency for a room, almost any omni is fine large or small with or without a cal file.
Exactly! For now, I don't care much if it's 100% accurate... I just want to see if there's differences between different set ups... (different speaker/mic positions, or between different speakers, or adding some improvised room treatment and see what changes, etc...).
With my mic I can get fairly consistent frequency measurements over 30-40Hz (depending on which speakers I'm using), all the way up to 20-25kHz.
I can see changes (consistently) if I change speaker position or mic position.
I can see clear differences in freq. response between different speakers.
I can even calculate the distance of where the main reflections happen and see some disappear when I hang a blanket on wall.
I can also confirm there's little to no difference between 2 different DACs.
Some people here seem to fail to understand that I'm not trying to build a audio certification lab at home... nor that I'm not willing to spend a lot of money on a fancy measurement mic. I'm just experimenting with REW and trying to understand how things work for now.
@Blumlein 88 thanks for baring with me and for all your patience and valuable tips!
I borrowed some mics from a friend and I'm going to do some measurements with them tomorrow... curious to see how big of a difference I'll see (in frequency response) between those mics...
And... for the despair of those obsessed with accurate measurements... neither of those is a measurement mic! (I got a ribbon, a LDC cardioid and a dynamic one).
It'll be a wild mic party!