Review on 🎤 Adjustable Electret Microphone Amplifier by Adafruit by Erin Walker

I trust people so if this unit has good response at low frequencies but worse above 1kHz I have to assume I just got a bad block. The vendor's data says the electret microphone has a full frequency range (about 25Hz-20kHz), I wonder if the supporting circuitry has such a good wide range. My O'scope says no, but then again I have to assume my module is just a lemon until I get another one that confirms a correct output. The bottom line for me is that this device is best for low audio detection requirements (25Hz - 500Hz), but the output drops drastically on the device I have. never mind I'll just order another one.