How to choose a mic and make sure not to overcahrge it


I'm not sure that's the right forum to ask this question but I'll do it anyway .

in my project, I've to listen to different machines using an MEMS mic by fixing the mic directly on the machine ,
the problem is that I get, is that all the records that I need are overchaged so useless, my question is how should I choose the mic for really loud measurements.

here is a link to the device:

thanks in advance for any hint.

Best Answer

You could lower the gain on the amplifier by changing R4 to a lower value. That should help a lot.

Right now, the amplifier has a gain of 67. If you change R4 to 1.5K then the gain would be one. I would start by reducing the gain to 10 (R4=15K.)

How to calculate gain: Gain = R4/R3

ETA: The pictures don't show the locations of R4 and R3. You will need to see which is marked 105 (100K) - that will be R4. You could also download the eagle files and check the layout.

Building on Andy aka's information, you should probably set your gain down to 1 (R4=1.5K)