2nd try: Looking for 2.4µF non-polarized caps

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#21
You can't use a polarised capacitor in either leg. You must use a non-polarised capacitor with sufficient voltage rating for the intended use. The convention is to place it in the (+) side, but it will function correctly as long as it is in series with the tweeter.
 
#22
johnmath said:
You can't use a polarised capacitor in either leg. You must use a non-polarised capacitor with sufficient voltage rating for the intended use. The convention is to place it in the (+) side, but it will function correctly as long as it is in series with the tweeter.
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Thank you for clarifying, John. So ... if I'm reading the earlier links correctly (Solen, Panny, Dayton) I'm back to Square One. They all seem polarized because they don't state otherwise.
 
#23
deckeda said:
Thank you for clarifying, John. So ... if I'm reading the earlier links correctly (Solen, Panny, Dayton) I'm back to Square One. They all seem polarized because they don't state otherwise.
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Capacitors supplied as being for loudspeaker crossovers will not be polarised, even if they are electrolytic.

Film capacitors are not polarised (although there are polar and non-polar plastic materials used for the film which does have some bearing on sound quality, but not whether they need a DC polarising voltage).

Electrolytic capacitors need a polarising voltage to maintain the anodised film that insulates the two halves and makes the dialectric. Reverse biasing an electrolytic capacitor erodes the dialectric insulating film and eventually the capacitor will short circuit, overheat and possibly explode.

Bi-polar electrolytic capacitors are two polarised electrolyte capacitors (double the nominal value of the component) in series back to back in one package. The leakage current through each one of the two capacitors when reverse polarised is enough to create and maintain the dialectric film of the other capacitor of the two. You can make your own bi-polar 2.35µF capacitor by putting two 4.7µF polar electrolytic capacitors in series back to back, i.e. (+) joined to (+), or (-) joined to (-). It doesn't matter which way you do it.
 
#26
A terminal marked »+« or red, doesn't mean, as others yet said, that it is positive in the sense of the current through the speaker. AF signal current always is AC. It's just a convention for most (there are notable exceptions as well!) manufacturers that the voice coil will move outward when a low voltage battery is connected with it's positive terminal to the marked one.

Without the intention to offend anyone here, I'd also recommend a non-polarized foil capacitor instead of a 'lytic. Elytics simply are cheap, but foil caps aren't unjustifiably expensive, see the Mouser recommendation above, plus they usually are of tighter tolerance and are more reliable over time. No, I won't comment on sound quality here 😉.

Best regards!
 
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