How to approach this...
BeautifulLight said:
There are certainly holes in my understanding and no I am not familiar with calculating series/parallel impedance -I'm still stuck on understanding how a capacitor "blocks" low frequencies.
Electricity seems baffling at first because the basic units are all named after people, not something that'd help you remember them.
The analogy of water in pipes is popular but can lead one to some misconceptions...
so let's stick to electrical charges in the wires.
You can think of charge as sort of a fluid. We measure it in a strange unit "Coulombs
a Coulomb being the amount of charge that would be carried by 6X10^18 electrons...
it's large but not huge... imagine a waterglass full of charges and call it a Coulomb.
Look up who Coulomb was and you'll see why they picked that name.Impedance is just what it sounds like - something that impedes the movement of charge.
A copper wire allows almost unimpeded movement of charge. So it has not much impedance.
We measure impedance in Ohms, a measure of the difficulty with which charges are pushed through something.
A typical loudspeaker has four or eight ohms which isn't a lot.
When you connect two impedances in series they numerically add. (it's a vector addition but save that detail for later)
When you connect two impedances in parallel, you must add their reciprocals and take the reciprocal of that result. We call that reciprocal "Mhos', Ohms spelled backward(no kidding)
So: 2 four ohm loads in
series gives four ohms plus four ohms = 8 ohms
likewise 2 four ohm loads in
parallel gives 1/4mho + 1/4mho = 1/2 mho, and 1/(1/2mho) = 2 ohms
Now a capacitor's impedance is directly related to frequency
the equation is :
ohms = 1/(2 X pi X frequency X Farads)
So your 500 uf capacitor has what impedance at 100 hz?
1/( 2 X 3.14 X 100 X 500X10^-6) = 3.18 ohms
Can you figure what it'd be at 1000 hz? and at 10 hz?
And why it'd short out your amp at high frequency were it connected across speaker output terminals?
I hope you get interested and dig into electronics.
old jim