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If a circuit calls for a capacitor with a specific capacitance, what happens if a capacitor with a different capacitance is substituted?

I have a circuit that calls for a 250uF capacitor to power a small speaker. What would happen if I substituted it for a capacitor with less/more capacitance?

Why can't I substitute it for a 220uF capacitor?

Why can't I substitute it for a 300uF capacitor?

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VerySeriousSoftwareEndeavours
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  • It depends on what the capacitor is supposed to do in the circuit. Substituting the steel on the roof of your car for a different material is a lot different than substituting the steel in your engine for a different material because even though the same thing is in both places, it's meant to do different things. – DKNguyen May 29 '20 at 21:54
  • A capacitor can only power a speaker for miliseconds. It is obviously not powering the speaker. – pipe May 29 '20 at 21:55
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    If it's a series capacitor between amp and speaker : 220uF will give marginally less bass; 300uF marginally more. If it's a 3 inch speaker that probably won't make any difference at all. –  May 29 '20 at 22:00
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    An largish electrolytic capacitor such as the one you are discussing will typically have a tolerance no better than +/-20% and perhaps as bad as +80/-20%. So a 10-15% difference is unlikely to have much noticeable effect in an audio application. – Spehro Pefhany May 29 '20 at 22:03
  • The capacitor sits between the audio amplifier chip and the speaker. If it is not needed to power the speaker in any way, why is it needed in the first place? Can i remove it entirely from the circuit? – VerySeriousSoftwareEndeavours May 29 '20 at 22:09
  • It isn't "powering" anything. It's filtering. – JYelton May 29 '20 at 22:22

1 Answers1

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The capacitor is there to block DC from blowing up the speaker. It's value is not that important. However it affects the bass response, which most likely is not that great to begin with, as you describe it being a small speaker.

Justme
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