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A short response on the math is such:


Any time you have a circuit with speakers in paralell you use this formula:

1/((1/x)+(1/y).....) Basicly you keep on adding more 1 divided by whatever as you needed

So as an example. If i had a speaker of 8 ohms and 16 ohms and i put them in paralell, i'm just grabbing random numbers btw, it would look like:

1/((1/8)+(1/16)) = 5.33

Now if I added another speaker say 1 4 ohm speaker

1/((1/4)+(1/8)+(1/16))=2.28

You see how It works now? Also on the 1/4 if you have mroe than one you could do 2 there instead of 1. Series is much easier you just add the ohms per speaker up.
 

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Or to simplify the above for those that still don't get it.

Let's start with two of the three 8 ohm speakers, then do this:

8x8=64, 8+8=16. Now divide 64 by 16. It should equal 4

Now take that 4 and do the same thing with the remaining 8 ohm speaker.

4x8=32. 4+8=12. 32 divided by 12 = 2.6666666666667
 

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Or to simplify the above for those that still don't get it.

Let's start with two of the three 8 ohm speakers, then do this:

8x8=64, 8+8=16. Now divide 64 by 16. It should equal 4

Now take that 4 and do the same thing with the remaining 8 ohm speaker.

4x8=32. 4+8=12. 32 divided by 12 = 2.6666666666667
*sniff* *sniff* you saying I don't explain good!!!! LoL

Also an easy self check that tells you if your math was right is simple. If your number you got is smaller than the resistance of the smallest speaker your right! So in the case above where i had a 4 8 and 16 ohm speaker my answer HAS to be smaller than 4, and it was!
 

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I must have a simple mind.

If all the parallel resistances are the same, simply divide one resistor's resistance by the total number of resistors. Or in your case 8/3 as already posted.

If the any of the resistances are different, take the inverse of each resistor's resistance and sum (add) them up. Then take the inverse of the answer.

In your case with 8 ohm resistors:
So 1/8 + 1/8 + 1/8 = 0.375

Then take the inverse of that for the parallel resistance:
1/0.375 = 2.67
 

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I must have a simple mind.

If all the parallel resistances are the same, simply divide one resistor's resistance by the total number of resistors. Or in your case 8/3 as already posted.

If the any of the resistances are different, take the inverse of each resistor's resistance and sum (add) them up. Then take the inverse of the answer.

In your case with 8 ohm resistors:
So 1/8 + 1/8 + 1/8 = 0.375

Then take the inverse of that for the parallel resistance:
1/0.375 = 2.67
Exactly how I do the calculation in my head. Easy when the resistance of each of the resistors is the same.
 
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