You cut the LF to reduce FM distortion.
In the case of a vented enclosure the driver will unload below the tuning frequency and large signal in this region can cause the driver to flap around with no output at best, and at worst can smash into the backplate.
When (active) XOing to (sub) woofers one of the biggest pluses is the improved midrange because of less bass to the midtweeter.
dave
In the case of a vented enclosure the driver will unload below the tuning frequency and large signal in this region can cause the driver to flap around with no output at best, and at worst can smash into the backplate.
When (active) XOing to (sub) woofers one of the biggest pluses is the improved midrange because of less bass to the midtweeter.
dave
Im using big 200v 1000uF cap, so I think I was safe.
I have bought today 2 pair to connect them the right way.
Thanks
The voltage rating is irrelevant, the fact it is polarised is the problem. You only need a few volts reverse voltage to make a firework 🙂
planet10 explained it.
Im using a subwoofer to play LF. No need for my Fullrange to move like crazy trying to make pseudo LF.
What does the amplifier 'see' in terms of impendance with the capacitors added at speaker level? Also do the capacitors essentially change any of T/S parameters of the speaker?
The amp will see a gradually increasing impedance as frequency goes lower. The T/S parameters are usually affected, but only by a small amount as you normally size the cap to be effective below box resonance.
Basically yes they are, but I would rather buy one than make one using back-to-back polarised ones. Any voltage over 50V will be fine for a 100W/8R amp.
Ok, But i didnt find any non polarized cap that have low impedance like polarized cap.
By now I have 2 Rubicon ZLG (ultra low impedance) polarized 35v 1000uf with an amplifier of 33w/8R.
What you tell me is Im better to use a non ploarized cap instead of those right? Like the Panasonic M (SU replacement) or Rubycon NA.
By now I have 2 Rubicon ZLG (ultra low impedance) polarized 35v 1000uf with an amplifier of 33w/8R.
What you tell me is Im better to use a non ploarized cap instead of those right? Like the Panasonic M (SU replacement) or Rubycon NA.
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In practical terms, it matters little (2x polarised back-to-back versus one non-polarised). You will need to know the ESR (Equivalent Series Resistance) of each capacitor type, then judge whether 2 or the Rubicon caps in series have lower ESR than a single non-polarised cap.
A polarised electrolytic capacitor is in itself two capacitors in series. The capacitance value and voltage rating is set by the thickness of oxide coatings which are formed on the two electrodes of the capacitor. One electrode has a thick coating which can withstand the specified voltage rating of the capacitor. The other has a much thinner coating which can withstand only a few volts. But because it is thinner, it has a much higher capacitance. Capacitances in series have voltage drops in (inverse) proportion to the capacitances, just as resistances in series have voltage drops in proportion to the resistances.
Note that you have to have both electrodes oxide coated, or you will get electrolysis (gas generation) on the "bare" electrode. If you exceed the coating's voltage rating, you again get gas generation - and a subsequent explosion if the pressure rises high enough.
So, imagine a 1000 uF 30 volt capacitor. Those values are set by one electrode. The other might be 10,000 uF and 3 volts. Now apply a voltage that varies from 0 to 33 volts. 30 volts will be dropped across the 1000 uF electrode and 3 volts across the 10,000 uF electrode. Since in your application you need to handle the other polarity as well, you need to add a second capacitor "back to back".
A "non polarised" capacitor "cuts out the middle man" by having both electrodes coated with thick oxide layers. In the above example, both electrodes would have "1000 uF" coatings. Ohm's law shows that the two coatings in series result in a 500 uF capacitor.
A polarised electrolytic capacitor is in itself two capacitors in series. The capacitance value and voltage rating is set by the thickness of oxide coatings which are formed on the two electrodes of the capacitor. One electrode has a thick coating which can withstand the specified voltage rating of the capacitor. The other has a much thinner coating which can withstand only a few volts. But because it is thinner, it has a much higher capacitance. Capacitances in series have voltage drops in (inverse) proportion to the capacitances, just as resistances in series have voltage drops in proportion to the resistances.
Note that you have to have both electrodes oxide coated, or you will get electrolysis (gas generation) on the "bare" electrode. If you exceed the coating's voltage rating, you again get gas generation - and a subsequent explosion if the pressure rises high enough.
So, imagine a 1000 uF 30 volt capacitor. Those values are set by one electrode. The other might be 10,000 uF and 3 volts. Now apply a voltage that varies from 0 to 33 volts. 30 volts will be dropped across the 1000 uF electrode and 3 volts across the 10,000 uF electrode. Since in your application you need to handle the other polarity as well, you need to add a second capacitor "back to back".
A "non polarised" capacitor "cuts out the middle man" by having both electrodes coated with thick oxide layers. In the above example, both electrodes would have "1000 uF" coatings. Ohm's law shows that the two coatings in series result in a 500 uF capacitor.
No you will be fine with those caps. But you don't need super low ESR ones, that is just a parameter for switch mode power supplies really, for very high frequency use.
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