You did not read about the LM386 gain and did not read about the electret mic that is definitely polarized. It will produce no output if it is connected backwards. Its metal case is connected to its "ground" pin (if it has only 2 pins) and the Jfet inside needs a positive current.
Why do you have such a tiny low power speaker? Headphones are tiny low power speakers.
I do not really understand the purpose of your comment.
I have read about the LM386 gain but must have mixed up that "fixed gain" part with another IC. I have read about so many op-amps in the last few weeks to try to find one that works for my project and I am quite busy with my medical studies, so it isn't surprising that I mix up some stuff. Where do you think did I get the number 20 ( which is correct if there is nothing connected to pins 1 and 8 ) from ?
If the mic is polarized, how comes it has no marking on the pins to differentiate between the Gnd pin and the Vcc/Output pin ? And how comes it works on my PC and the LM393 circuit in either directions. I have seen many different electret mics online where both pins were clearly different since they were polarized but the ones I use don't have any such feature.
I am really bad with Op-amps but I know how headphones work, thank you. My project simply requires a speaker of around the same diameter as the mic.