As teacher you are not only tough but unfair:
but why isn't that an high pass filter as well?
I still don't get why C4 R6 do not configure as an high pass passive filter.
understand C1 is there to prevent DV voltage to reach the AC source, but I don't understand how come such event can occur,
Any audio amplifier has a frequency responce, it wil only amplify frequencies over a certain range, so you might call it a band pass filter but no one else will. It is important that you use the same words as the rest of the world if you want to communicate with them.
Without C2 & 3 the power supply might oscillate or your chip might oscillate so making the whole circuit not work.
One end of the microphone is connected to your vertuial ground. Any DC offset on the output of the op amp will produce the corresponding DC offset on the -ve input which will then put it through your microphone, thus destroying or damaging it. Remember a speaker and microphone are essentially the same thing so any DC signal will push the diaphragm to one side distorting any input.
Which means you do not suggest to even try the circuit without those? I'm having difficulties in sourcing capacitors here in this s**th**e where I live.....
the cut-off frequency
Then what values of capacitor are available there in "s**th**e"?If you have the 1uF (C4) then get more of those for the 4.7u (C3): place 4 or 5 in parallel.Maybe you can live without the 100uF (C2).Again, depending on what you have available, there may be an alternative.
Quotethe cut-off frequencyDo you know what that means? The frequency where the capacitave reactance equal the resistance is the 3dB point. It is not the point where no more signal is let through.
If this is not good enough Then you are better off using a larger capacitor than lowering the resistance this is to make the vertuial ground more robust than it would be at 10K. But you can up it to 10K. If you want.
Increasing the capacitor value lowers the beak frequency as does increasing the resistor value. By using lower values of resistor you make more current flow through the resistors and so the vertuial ground is more robust. That is to say it is less suceptable to noise and disturbance.
Greater capacitor doesn't mean greater current draw at a specific frequency?
QuoteGreater capacitor doesn't mean greater current draw at a specific frequency?Sorry I don't know what you mean.What current are you talking about?